The Science Behind the Spray

No secrets. No empty claims. Discover the real research behind every drop of Dual-Clear.

The Science Behind the Spray

No secrets. No empty claims. Discover the real research behind every drop of Dual-Clear.

Niacinamide 

  • The role of nicotinamide in acne treatment (2017)

  • The effect of 2% niacinamide on facial sebum production (2006)

  • Mechanistic Insights into the Multiple Functions of Niacinamide (2024)

Key Findings

  • 6 of 8 studies using topical nicotinamide led to significant reduction in acne compared to baseline
  • Both studies using oral nicotinamide supplements resulted in significant acne reduction
  • No major adverse side effects noted
  • Nicotinamide has potent anti-inflammatory properties
  • Addresses antibiotic resistance concerns in acne treatment

 

What's in the DUAL CLEAR MIST:

Each bottle contains 5% of niacinamide (yes 5%!) which is the same as prescription-strength concentrations used in dermatology clinics. 

 

Source: Walocko FM, Eber AE, Keri JE, Al-Harbi MA, Nouri K. Dermatol Ther. 2017 Sep;30(5). doi: 10.1111/dth.12481 Study Type: Systematic review of 10 clinical studies 

 

 

 

Key Findings

  • Japanese study: 2% niacinamide significantly lowered sebum excretion rate (SER) after 2 and 4 weeks
  • Caucasian study: Casual sebum levels (CSL) significantly reduced after 6 weeks
  • Sebum control is crucial as it's responsible for facial shine and comedonal/inflammatory acne lesions
  • Niacinamide modulates sebum production rather than just absorbing it

 

What's in the DUAL CLEAR MIST:

Each bottle contains 5% of niacinamide (yes 5%!) which is the same as prescription-strength concentrations used in dermatology clinics. 

 

Source: Draelos ZD, Matsubara A, Smiles K. J Cosmet Laser Ther. 2006 Jun;8(2):96-101. doi: 10.1080/14764170600717704 Study Type: Double-blind, placebo-controlled trial (100 Japanese subjects) + randomized split-face study (30 Caucasian subjects) 

Key Findings:

  • Ceramide and niacinamide-containing moisturizer (CCM) significantly improved non-inflammatory, inflammatory, and total acne lesions compared to hydrophilic cream after 8 weeks
  • Improvement in global worst score, hemoglobin index, melanin index, TEWL (trans-epidermal water loss), skin hydration, sebum production, and skin surface pH
  • No serious side effects from clinical application in mild to moderate acne patients
  • Ceramide and niacinamide-containing moisturizer in combination with anti-acne medication can significantly improve acne lesions and decrease cutaneous irritations toward satisfactory treatment outcomes

 

What's in the DUAL CLEAR MIST:

Each bottle contains 5% of niacinamide (yes 5%!) which is the same as prescription-strength concentrations used in dermatology clinics. 

 

Source: Tempark T, et al. Journal of Cosmetic Dermatology. 2024 Feb 1;23(5):1758-1765. doi: 10.1111/jocd.16212

Eucalyptus Essential Oil 

  • Essential Oils in Acne Treatment - Comprehensive Review (2022)

  • Sebaceous Gland Inhibition Study

  • Anti-Propionibacterium Acnes Activity (2019)

  • Anti-inflammatory and Skin Protection (2024)

Key Findings

1. Chemical Composition: 

  • 1,8-cineole (eucalyptol): 11.3–76.6% (main active ingredient)
  • p-cymene: 8.8–20.2%
  • α-pinene: 5.6–20.1%
  • D-limonene: 6.2%
  • γ-terpinene: 8.9%
  • α-terpineol acetate: 4.8%
  • Alloaromadendrene: 4.0%

2. Anti-Acne Properties:

Antimicrobial Activity:

  • Kills harmful bacteria that cause acne
  • Effective against C. acnes, S. aureus, and S. epidermidis
  • 1,8-cineole is especially good at targeting S. epidermidis

Sebum Production Control:

  • Significantly reduces the size of overactive oil glands
  • Lowers excess oil (sebum) that clogs pores and forms pimples
  • Dual action: less oil and fewer infections

Anti-inflammatory Effects:

  • Provides anti-inflammatory and antioxidant benefits
  • Reduces production of tyrosinase and melanin
  • Lightens acne scars and evens skin tone

Clinical Efficacy:

  • A cream with 2% eucalyptus oil was more effective than a 5% benzoyl peroxide acne gel
  • Confirmed antimicrobial and anti-inflammatory action for treating acne

 

Source: Nurzyńska-Wierdak R, et al. Plants (Basel). 2022 Dec 24;12(1):90. doi: 10.3390/plants12010090 

Key Findings

  • Sebum Control: Eucalyptus oil shows promising results for reducing excess oil production
  • Alternative Pathway: Offers a different way to help manage acne besides traditional treatments
  • Sebaceous Gland Size: Helps shrink enlarged oil glands in the skin

Source: Referenced from search results - NOPR/ResearchGate

Key Findings

  • Antimicrobial Potency: Eucalyptus oil showed strong ability to kill P. acnes bacteria that are resistant to common antibiotics (macrolides)
  • Sebum Reduction: Clearly reduces excess oil on the skin
  • Resistance Management: Works well against acne bacteria that no longer respond to antibiotics

Source: Biomedical and Pharmacology Journal. 2019 Jan 29

Key Findings

  • Anti-inflammatory Properties: Eucalyptus globulus has strong anti-inflammatory effects
  • Antimicrobial Activity: Fights a wide range of germs and bacteria
  • Enzyme Inhibition: Blocks acetylcholinesterase (AChE), an enzyme linked to inflammation
  • Skin Applications: Useful for treating irritated and inflamed skin conditions

Mechanisms of Action:

 

1. Antimicrobial Activity:

  • 1,8-cineole is the main compound that kills bacteria
  • Works against both regular and antibiotic-resistant acne bacteria
  • Fights many types of skin infections

2. Sebum Regulation:

  • Shrinks overactive oil glands
  • Reduces extra oil (sebum) on the skin
  • Helps stop clogged pores (comedones) from forming

3. Anti-inflammatory Effects:

  • Calms redness and swelling in acne
  • Antioxidant action protects skin from damage
  • Soothes and relieves irritation

4. Scar Prevention:

  • Lightens dark acne marks and scars
  • Improves overall skin tone and texture
  • Supports faster healing of breakouts

Safety and Efficacy:

  • A cream with 2% eucalyptus oil worked better than a 5% benzoyl peroxide gel
  • Provides a natural alternative to chemical acne treatments
  • Effective against antibiotic-resistant bacteria
  • Tackles acne through multiple actions at once

 

Source: Springer Link. 2024 Nov 5. doi: 10.1007/s10787-024-01588-8

Hyaluronic Acid

  • Hyaluronic Acid Decreases Lipid Synthesis in Sebaceous Glands (2017)

  • Efficacy Evaluation of Topical Hyaluronic Acid Serum (2021)

  • Microbiome Effects (2023)

Key Findings

Sebum Production Reduction: 

  • The side treated with HA showed a clear drop in oil production
  • 15 out of 20 volunteers had much less oil on the HA-treated side
  • This reduction in oil was still significant 2 weeks after treatment

Animal Model Results: 

  • In hamsters, HA injections shrank the oil glands and lowered oil (lipid) production

Mechanism: 

  • HA works by blocking lipid production through the CD44/RhoA signaling pathway

Skin Type Differences:

  • Oily skin may react more strongly to HA than normal or dry skin

Source: Journal of Investigative Dermatology. 2017. doi: 10.1016/j.jid.2017.02.963 

Key Findings

• Skin Hydration: Skin moisture increased by 134% right after applying the product (p < 0.001)

• Sustained Hydration: A 55% increase in hydration was still present after 6 weeks (p < 0.001)

• Skin Improvements at Week 6:

  • Smoothness: 64% better
  • Plumping: 60% better
  • Hydration: 63% better
  • Fine Lines: 31% reduction
  • Overall Assessment: 43% improvement

• Safety: Excellent tolerance—no irritation or increase in skin inflammation (no rise in IL-1a)

• Mechanism: Improves the skin’s ability to hold water; works well for all skin tones and types (all Fitzpatrick skin types)

 

Source: Draelos ZD, et al. Dermatol Ther (Heidelb). 2021 Jun;26;11(4):1385-1394. doi: 10.1007/s13555-021-00566-0 

Key Findings

  • Pathogenic Bacteria Reduction: Applying HA to the face lowers harmful bacteria like Cutibacterium and S. aureus
  • Beneficial Bacteria Increase: Encourages growth of good bacteria on the skin
  • Microbiome Balance: Helps keep a healthy balance of skin microbes

Mechanisms of Action for Acne-Prone Skin

 

1. Sebum Production Regulation:

  • Directly reduces oil (lipid) production in the skin’s oil glands
  • Works through the CD44/RhoA signaling pathway
  • Lowers phosphorylated Akt levels (linked to oil production)
  • Especially effective for oily skin

2. Skin Barrier Function:

  • Maintains the skin’s natural moisturizing factors
  • Improves the skin’s ability to hold water
  • Strengthens the skin barrier without blocking pores

3. Anti-inflammatory Properties:

  • Calms inflammation caused by acne
  • Speeds up healing of acne lesions
  • Soothes irritated skin

4. Microbiome Support:

  • Lowers acne-causing bacteria (C. acnes)
  • Increases good bacteria
  • Supports a balanced, healthy skin microbiome

5. Non-comedogenic Hydration:

  • Gives deep hydration without making skin oily
  • Balances oil production
  • Safe and suitable for acne-prone skin

Source: Referenced from search results - Wiley Online Library

 

Green Tea Extract

  • Systematic Review and Meta-Analysis (2020)

  • Comprehensive Review - Tea Polyphenols and Sebum Production (2016)

Key Findings

• Inflammatory Lesions: Green tea extract (GTE) significantly reduced inflamed acne lesions (–9.38; 95% CI: –14.13 to –4.63)
• Topical vs Oral Application:

  • Topical GTE: Greatly reduced inflammatory acne (–11.39; 95% CI: –15.91 to –6.86)
  • Oral GTE: Only a small effect on inflammation (–1.40; 95% CI: –2.50 to –0.30)

• Non-inflammatory Lesions:

  • Overall: No significant reduction overall (–21.65; 95% CI: –47.52 to 4.22)
  • Topical GTE: Significantly reduced non-inflamed acne (–32.44; 95% CI: –39.27 to –25.62)
  • Oral GTE: No effect (0.20; 95% CI: 0.00 to 0.40)

•  Safety: No significant side effects seen with topical use
•  Conclusion: Applying GTE directly to the skin helps treat acne effectively and safely

 

Source: Kim S, Park TH, Kim WI, Park S, Kim JH, Cho MK. Phytother Res. 2021 Jan;35(1):374-383. doi: 10.1002/ptr.6809 

Key Findings

  • Sebum Production: Studies show that tea polyphenols in creams or gels can lower oil (sebum) production
  • Acne Treatment: Evidence supports using tea polyphenols to help treat acne
  • Application Routes: 7 studies tested topical (skin) use of tea polyphenols; 1 study looked at taking them by mouth
  • Tea Sources: Green tea used in 6 studies; 2 studies didn’t specify the tea type

Mechanisms of Action

 

1. PI3K-Akt-mTORC1 Pathway Inhibition:

  • EGCG lowers mTOR activity, which is linked to acne
  • EGCG blocks PI3K and mTOR by competing with ATP
  • Reduces overactive mTORC1 signaling that increases acne

2. Sebum Production Reduction:

  • EGCG cuts down fat (lipid) production in oil glands
  • Stops insulin and IGF-1 signals that trigger more sebum
  • Acts naturally to block mTORC1

3. Anti-inflammatory Effects:

  • Tea polyphenols reduce skin inflammation
  • Help calm irritation caused by P. acnes bacteria
  • Antioxidants protect skin from damage

4. Antimicrobial Activity:

  • EGCG stops the growth of P. acnes (Cutibacterium acnes)
  • Fights acne-causing bacteria

Key Components

  • EGCG (Epigallocatechin-3-gallate): Main active compound
  • Catechins: Make up 30–42% of green tea extracts
  • Flavonols: 5–10% of the extract
  • Other Flavonoids: 2–4% of the extract
  • Green tea has more polyphenols than other types of tea

 

Source: Saric S, Notay M, Sivamani RK. Antioxidants (Basel). 2016 Dec 29;6(1):2. doi: 10.3390/antiox6010002 

Tea Tree Oil

  • Comprehensive Review - Tea Tree Oil: Properties and the Therapeutic Approach to Acne (2023)

  • Basset et al. (1990) - RCT Single-blind

  • Enshaieh et al. (2007) - RCT Double-blind

  • Malhi et al. (2016) - 12-week uncontrolled pilot study

Key Findings

  • Tea tree oil has strong germ-fighting, calming, and protective effects
  • Helps reduce inflamed acne spots, especially papules and pustules
  • All reviewed human studies found it effective for treating acne, mainly inflammatory types
  • Few side effects reported; generally well tolerated
  • Works well against Cutibacterium acnes (formerly Propionibacterium acnes), a main acne-causing bacteria

Source: Nascimento T, Gomes D, Simões R, Miguel MG. Antioxidants (Basel). 2023 Jun 12;12(6):1264. doi: 10.3390/antiox12061264 

Key Findings

  • Inflammatory lesions: Benzoyl peroxide (BP) worked significantly better than tea tree oil (TTO) for reducing inflamed acne spots (p < 0.001)
  • However, both treatments were effective overall in reducing inflammation
  • Non-inflammatory lesions: No major difference between BP and TTO groups
  • Both treatments lowered non-inflamed acne (TTO group (p < 0.05), BP group (p < 0.01))
  • Safety: More side effects reported in the BP group (79%) compared to the TTO group (44%) (p < 0.001)
  • Adverse effects: Common issues included dry skin, itching, stinging, burning, and redness
  • Skin oiliness: BP showed increasingly less skin oiliness than TTO group (p < 0.02)

Source: Referenced in comprehensive review above 

Key Findings

 

• The treatment group had a 43.64% reduction in total acne lesions (p = 0.035, significant)
• The control group had a 12.03% reduction (p = 0.09, not significant)
• There was a clear difference between groups (p = 0.000)
• Tea tree oil 5% was 3.55 times more effective than placebo
• Only mild side effects reported

  • Pruritus: 10% in the TTO group, 6.66% in the control group
  • Burning sensation: 3.33% in the TTO group, 6.66% in the control group
  • Minimal scaling: 3.33% in the TTO group

Mechanisms of Action

  1. Antimicrobial activity - Kills acne-causing bacteria (C. acnes)
  2. Anti-inflammatory properties - Reduces swelling and redness in acne lesions
  3. Antioxidant effects - Protects skin from damage caused by free radicals
  4. Better tolerability - Fewer side effects than common treatments like benzoyl peroxide

 

Source: Referenced in comprehensive review above 

Key Findings

 

• Lesion Count Reduction:

  • Baseline: 23.7 acne lesions
  • After 4 weeks: 17.2 lesions
  • After 8 weeks: 15.1 lesions
  • After 12 weeks: 10.7 lesions
  • Total lesion counts improved significantly over time (P < 0.0001)

• Investigator Global Assessment (IGA) Score:

  • Baseline: 2.4
  • 4 weeks: 2.2
  • 8 weeks: 2.0
  • 12 weeks: 1.9
  • Significant improvement seen over time (P = 0.0094)

• Safety: No serious side effects reported
• Minor side effects: Minor issues included peeling, dryness, and scaling, all resolved on their own
• Conclusion: Tea tree oil products significantly improved mild to moderate acne and were well tolerated

 

Source: Malhi HK, Tu J, Riley TV, Kumarasinghe SP, Hammer KA. Australas J Dermatol. 2017 Aug;58(3):205-210. doi: 10.1111/ajd.12465 

Calendula Flower Extract

  • Systematic Review of Calendula for Wound Healing (2019)

  • Multifaceted Therapeutic Potential Review (2023)

  • Anti-Acne Gel Formulation Study (2025)

  • Anti-inflammatory Activity Study (MDPI)

Key Findings

Acute Wound Healing:

  • Faster reduction of inflammation and quicker growth of new tissue
  • Consistent positive results seen in 5 animal studies and 1 clinical trial
  • Healing improved through several different mechanisms

Chronic Wound Healing:

  • Venous ulcers: 2 clinical studies showed smaller ulcer size compared to untreated controls
  • Mixed results in diabetic leg ulcer healing
  • Moderate evidence that healing from inflammation was faster

Radiation Dermatitis Prevention:

  • 2 clinical trials tested prevention of skin damage after radiation therapy
  • One study found better results compared to trolamine cream
  • Results were mixed when compared to other standard treatments

Source: Givol O, et al. Wound Repair Regen. 2019 Sep;27(5):548-561. doi: 10.1111/wrr.12737 

Key Findings

 

Anti-inflammatory Mechanisms:

  • Cytokine Inhibition: Blocks key inflammation-causing proteins (IL-6, IL-1β, TNF-α, IFN-γ)
  • COX-2 Inhibition: Stops the COX-2 enzyme that drives inflammation
  • Nitric Oxide Reduction: Lowers nitric oxide production in a dose-dependent way
  • Safe Concentrations: Only becomes toxic to cells at high doses (147 μL/mL or more)

Active Compounds:

  • Triterpenoid fatty acid esters: Main anti-inflammatory ingredients
  • Faradiol esters: Most common types are lauryl, myristoyl, and palmitoyl esters
  • Secondary metabolites: Includes alkaloids, tannins, flavonoids, essential oils, sterols, saponins, carotenoids
  • Also contains triterpene alcohols, mucilage, polysaccharides, and resin

Clinical Applications:

  • Acute inflammation: Helps reduce swelling caused by dextran and carrageenan
  • Chronic inflammation: Effective against long-lasting swelling induced by formalin
  • Skin conditions: Supports cell repair, speeds up wound healing, and reduces inflammation

Source: Shahane K, et al. Pharmaceuticals (Basel). 2023 Apr 18;16(4):611. doi: 10.3390/ph16040611 

Key Findings

  • Anti-acne formulations containing Calendula officinalis extract showed efficacy
  • Combination therapy with Tretinoin enhanced effectiveness
  • Topical application suitable for acne treatment

Source: ResearchGate publication (Assessment of Anti-Acne Gel Formulations) 

Key Findings

  • iNOS inhibition: Helps treat injured skin by blocking iNOS (an enzyme linked to inflammation)
  • Skin conditions: Effective for skin diseases where iNOS plays a role
  • Calendula oil: Shown to be helpful in treating various skin problems

Mechanisms of Action for Acne-Prone Skin

 

1. Anti-inflammatory Effects:

  • Cytokine Modulation: Lowers inflammatory proteins (IL-6, IL-1β, TNF-α, IFN-γ)
  • COX-2 Inhibition: Reduces production of inflammatory chemicals
  • Nitric Oxide Reduction: Less nitric oxide means less inflammation
  • Inflammation Resolution: Speeds up the healing phase of inflammation

2. Wound Healing Properties:

  • Granulation Tissue Formation: Boosts growth of new healing tissue
  • Cell Rejuvenation: Encourages skin cell renewal and repair
  • Epithelization Acceleration: Faster rebuilding of the skin barrier
  • Tissue Regeneration: Helps damaged skin heal more effectively

3. Skin Barrier Support:

  • Soothing Effects: Calms irritated, inflamed skin
  • Protective Properties: Shields skin from further harm
  • Moisture Retention: Keeps skin hydrated and strengthens the barrier
  • Antimicrobial Activity: Prevents secondary infections

4. Acne-Specific Benefits:

  • Post-inflammatory Healing: Fades acne marks and scars
  • Lesion Resolution: Speeds healing of active breakouts
  • Skin Texture Improvement: Promotes smoother, healthier skin
  • Redness Reduction: Minimizes visible redness and irritation

Safety Profile

  • Well-Tolerated: Used traditionally with a good safety record
  • Low Cytotoxicity: Safe at recommended amounts
  • Topical Application: Gentle for sensitive, acne-prone skin
  • Natural Origin: Plant-based alternative to synthetic treatments

Clinical Evidence Summary

  • Moderate to strong proof of anti-inflammatory effects
  • Consistent positive results in animal and human studies
  • Effective for quickly reducing acute inflammation
  • Helpful in wound healing and skin repair
  • Can be combined with other acne treatments

Source: MDPI. Anti-Inflammatory Activity of Calendula officinalis L. Flower Extract 

Squalane

  • Squalene Peroxidation and Biophysical Parameters in Acne-Prone Skin: A Pilot “In Vivo” Study

  • Daily use of a bakuchiol and squalane-containing face serum impacts skin esthetics

Key Findings

  • This pilot study looked at how squalene (an oil in skin) oxidizes in acne-prone skin compared to healthy skin.
  • The goal was to measure and compare squalene and its oxidized form (squalene peroxide).
  • While the main focus was squalene, the findings help explain why squalane (the stable version) may be useful.

Quantitative Results with Statistical Significance:

  • Acne-prone skin had higher levels of squalene and its peroxide form.
  • More sebum and higher porphyrin levels were linked to more oxidized squalene.
  • This shows that oxidized squalene contributes to acne by irritating skin and clogging pores.
  • Because squalene is unsaturated, it easily oxidizes into squalene monohydroperoxide, which is strongly comedogenic.

Mechanism of Action:

  • Squalene is a key part of human sebum.
  • In acne-prone skin, squalene turns into an oxidized, irritating form—especially after sun exposure.
  • This oxidized squalene causes inflammation and helps acne form.
  • Squalane, however, is fully saturated and does not oxidize.
  • Small amounts of squalane occur naturally in skin oil and are considered safe and stable.

Safety Profile:

  • The study didn’t directly test squalane’s safety.
  • However, because squalane does not oxidize, it likely avoids the harmful effects of oxidized squalene.
  • Squalane is generally known to be non-comedogenic and well-tolerated.

Clinical Relevance for Acne Treatment:

  • The findings suggest that using squalane instead of squalene can help moisturize acne-prone skin without causing oxidation or clogged pores.
  • Squalane is stable, non-irritating, and helps hydrate skin—important since acne treatments often dry the skin out.
  • Its non-comedogenic nature makes it a good choice for people with acne.

 

Source: Condrò, G., Sciortino, R., & Perugini, P. (2023). Squalene Peroxidation and Biophysical Parameters in Acne-Prone Skin: A Pilot “In Vivo” Study. Pharmaceuticals, 16(12), 1704. DOI: 10.3390/ph16121704

Key Findings

  • This study was done with 50 healthy Indian women aged 18–50 with medium to tan skin tones (Fitzpatrick types III and IV).
  • For four weeks, they applied a face serum with bakuchiol and squalane once daily at night.

Quantitative Results with Statistical Significance:

  • The serum was safe and well-tolerated.
  • Although the main goal was to look at overall skin appearance, the study noted that:
  • Squalane works as a moisturizer and antioxidant.
  • Natural squalene in skin oil can turn into squalene peroxides, which can clog pores and worsen acne.
  • Squalane, which is the hydrogenated (more stable) version of squalene, keeps the moisture benefits without this problem.

Mechanism of Action:

  • Squalane is a stable, non-greasy oil that doesn’t clog pores.
  • It copies the skin’s natural oils to hydrate and protect the skin.
  • It helps keep skin moist and supports a healthy skin barrier—even for acne-prone skin.

Safety Profile:

  • The study found the serum was safe to use, with no major side effects reported.

Source: Rastogi, R., & Gholap, A. (2023). Daily use of a bakuchiol and squalane-containing face serum impacts skin esthetics. CosmoDerma, 3, 182. DOI: 10.25259/CSDM_224_2023

Arnica Montana Flower Extract

  • Clinical Trials, Potential Mechanisms, and Adverse Effects of Arnica as an Adjunct Medication for Pain Management

  • Anti-Inflammatory Activities of Arnica montana Planta Tota versus Flower Extracts: Analytical, In Vitro and In Vivo Mouse Paw Oedema Model Studies

Key Findings

  • This review article looked at many clinical studies on Arnica, mainly for pain relief.
  • While not directly about acne, it shares helpful information about Arnica’s anti-inflammatory and antibacterial effects, which can be relevant for acne.

Quantitative Results with Statistical Significance:

  • The review found that Arnica creams and gels help reduce pain and swelling, thanks to their anti-inflammatory, antioxidant, and antimicrobial properties.
  • It did not give specific numbers for acne, but these benefits are well-supported in studies on other conditions like post-surgery pain and muscle aches.

Mechanism of Action:

  • Arnica contains special compounds (helenalin and dihydrohelenalin) that block NF-κB, a key driver of inflammation.
  • This stops the release of inflammation-causing proteins in the skin.
  • Arnica also fights bacteria and reduces oxidative stress, which can help protect skin.

Safety Profile:

  • Arnica is usually safe when used on the skin.
  • Taking it by mouth is not recommended because it can be toxic.
  • Some people with sensitive skin may get irritation.
  • Germany’s Commission E approved Arnica flower for external use only (bruises, swelling, joint pain).

Clinical Relevance for Acne Treatment:

  • While Arnica is mainly used for bruises and sore muscles, its anti-inflammatory and antibacterial actions could help with acne.
  • Reducing inflammation can mean fewer and less severe pimples.
  • Fighting bacteria may help control acne-causing germs.
  • Arnica could be a helpful ingredient in acne products to calm redness and irritation.
  • However, more studies are needed to prove exactly how well Arnica works for acne.

Source: Iannitti, T., & Palmieri, B. (2021). Clinical Trials, Potential Mechanisms, and Adverse Effects of Arnica as an Adjunct Medication for Pain Management. Medicines, 8(10), 58. DOI: 10.3390/medicines8100058

Key Findings

  • This study compared how well whole Arnica montana plant extracts worked versus just the flower extracts.
  • Researchers used lab tests (to see how they block inflammation pathways) and a mouse paw swelling model.
  • The goal was to see if the whole plant worked better at reducing inflammation.

Quantitative Results with Statistical Significance:

  • Whole plant extract blocked NF-κB (a key inflammation trigger) much more effectively (IC50 = 15.4 μg/mL) than flower extract (IC50 = 52.5 μg/mL).
  • It also reduced swelling in mice more than flower extract.
  • These results show the whole plant extract has stronger anti-inflammatory effects.

Mechanism of Action:

  • Arnica contains active substances like sesquiterpene lactones, flavonoids, and phenolic acids.
  • The sesquiterpene lactones mainly reduce inflammation by blocking NF-κB and enzymes (5-LO and COX-2) that create inflammatory chemicals.
  • Using the whole plant provides a broader mix of these helpful substances, leading to better results.

Safety Profile:

  • The study was done in lab tests and animals, not humans.
  • Although results were promising, more studies are needed to confirm safety and tolerability for people, especially for acne treatment.

Clinical Relevance for Acne Treatment:

  • The strong anti-inflammatory effects are important for calming red, swollen acne lesions.
  • Whole plant extracts may work better than flower-only extracts in reducing acne-related inflammation.
  • Less inflammation can mean less pain, faster healing, and more comfort.
  • Arnica’s known benefits in wound healing may also help fade red marks and discoloration after acne.

Source: Kiselova-Kaneva, Y. D., Badjakov, I., Dincheva, I., & Caretto, S. (2023). Anti-Inflammatory Activities of Arnica montana Planta Tota versus Flower Extracts: Analytical, In Vitro and In Vivo Mouse Paw Oedema Model Studies. Plants, 12(6), 1348. DOI: 10.3390/plants12061348

Allantoin

  • Treatment of acne vulgaris comparing two similar lotion formulations, one with ('Actinac') and one without chloramphenicol

  • Allantoin for Skin: Benefits, Uses, and Expert Tips

Key Findings

  • This was a double-blind, randomized study with 37 people who had acne vulgaris.
  • The study compared two similar lotions: one with the antibiotic chloramphenicol and one without it.
  • Both lotions also contained Allantoin.
  • Patients used the lotion twice a day for 4 days, then once every night for 3 months.

Quantitative Results with Statistical Significance:

  • Both lotions significantly reduced acne lesions at all check-ins.
  • After 3 months:
  • The antibiotic lotion reduced average lesion counts from 28.8 to 9.3.
  • The lotion without the antibiotic reduced counts from 39.5 to 14.3.
  • While the antibiotic group improved faster in the first month, by 3 months the difference was not statistically significant.
  • This suggests that the base lotion with Allantoin helped improve acne on its own.

Mechanism of Action:

  • Allantoin helps soften and remove dead skin cells (keratolytic), moisturizes, and soothes irritation.
  • It promotes new cell growth and healing, which helps repair damaged skin and calm inflammation.
  • Although this study didn’t test Allantoin separately, its presence likely contributed to the improvements seen.

Safety Profile:

  • No major side effects were reported from the lotion containing Allantoin.
  • Allantoin is generally safe and well-tolerated when used on the skin.

Clinical Relevance for Acne Treatment:

  • While this study mainly looked at the antibiotic, the lotion without it still reduced acne, showing Allantoin’s helpful role.
  • Allantoin supports healing, reduces irritation, and moisturizes skin, making it a good addition to acne products.
  • It can help counteract dryness and redness caused by stronger acne treatments, improving skin’s appearance and comfort.

Source: Fraser, N. B., Main, R. A., Stewart, T. W., & Thornton, E. J. (1980). Treatment of acne vulgaris comparing two similar lotion formulations, one with ( 'Actinac' ) and one without chloramphenicol. Current Medical Research and Opinion, 6(7), 461-465. DOI: 10.1185/03007998009109468

Key Findings

  • This article brings together insights from dermatologists and past research about allantoin.
  • It mentions a 2015 study on comfrey extract (which contains allantoin) and a 2010 study using scar gels with allantoin.

Quantitative Results with Statistical Significance:

  • The article describes allantoin as a strong water-based moisturizer, a mild exfoliator, and an anti-inflammatory ingredient.
  • While it doesn’t give specific numbers for acne, it notes allantoin helps prevent skin dryness, which is helpful for acne-prone skin.
  • In the 2010 study, scar gels with allantoin improved skin lesions.

Mechanism of Action:

  • Allantoin helps keep moisture in the skin.
  • It gently removes dead skin cells by boosting skin turnover.
  • It calms inflammation and soothes irritation.
  • It may also help wounds and scars heal faster by lowering inflammation.

Safety Profile:

  • Allantoin is usually safe, non-irritating, and works well for sensitive skin.
  • It is widely used in many skincare products.

Clinical Relevance for Acne Treatment:

  • Allantoin’s moisturizing helps prevent dryness, which can cause the skin to produce more oil.
  • Its anti-inflammatory effects calm redness and irritation from acne.
  • Gentle exfoliation helps keep pores clear.
  • While it doesn’t directly treat acne, it supports skin health and reduces side effects from stronger acne treatments.

Source: Mayer, B. A. (2021, December 8). Allantoin for Skin: Benefits, Uses, and Expert Tips. Healthline. https://www.healthline.com/health/allantoin-for-skin

Glycerin

  • Randomised controlled trial of topical kanuka honey for the treatment of acne

  • Glycerin-based Leave-on Products Provide Fast-acting Hydration in People with Moderate Skin Dryness

Key Findings

  • This randomized controlled trial tested Honevo, a cream with 90% medical-grade kanuka honey and 10% glycerin, for facial acne.
  • Researchers compared using the honey product plus antibacterial soap vs. using antibacterial soap alone.
  • The main goal was to see how many people had at least a 2-point improvement in acne severity after 12 weeks.

Quantitative Results with Statistical Significance:

  • The study did not find clear evidence that adding the honey-glycerin product worked better than soap alone.
  • No significant improvement in acne severity using the main measure.
  • A detailed analysis adjusting for starting acne levels showed weak evidence of improvement in the honey group (odds ratio 2.0, p=0.075).
  • Most secondary measures showed no benefit.
  • People using the honey product reported feeling their skin improved, but this could be biased since it was self-rated.

Mechanism of Action:

  • The study looked at honey and glycerin together.
  • Glycerin acts as a humectant, drawing moisture into the skin and helping maintain a healthy skin barrier.
  • While this wasn’t tested directly, good hydration may help reduce dryness from other acne treatments.

Safety Profile:

  • No major side effects were reported from the honey-glycerin product, showing it was safe for the skin.

Clinical Relevance for Acne Treatment:

  • This study did not show strong evidence that the honey-glycerin mix improves acne better than antibacterial soap alone.
  • However, glycerin’s moisturizing effect can help prevent dryness and irritation when used with other acne products.
  • More studies are needed to see if glycerin can directly help with acne by affecting oil production or inflammation.

 

Source: Semprini, A., Braithwaite, I., Corin, A., Davitt, M., Sheahan, D., Tofield, C., ... & Beasley, R. (2016). Randomised controlled trial of topical kanuka honey for the treatment of acne. BMJ Open, 6(2), e009448. DOI: 10.1136/bmjopen-2015-009448

Key Findings

  • This randomized, evaluator-blinded study tested how well three glycerin-based products (moisturizer, lotion, cream) hydrated dry skin.
  • 30 women with moderate leg dryness tried a single application.
  • Another 32 women with sensitive, dry, itchy skin used a glycerin cream twice a day for 2 weeks.

Quantitative Results with Statistical Significance:

  • All products significantly improved skin hydration after one use, measured visually and with a corneometer.
  • In the 2-week group, dryness, itching, and hydration improved noticeably by day 1 and stayed better throughout the study.
  • Results were statistically significant compared to baseline and no treatment.

Mechanism of Action:

  • Glycerin is a humectant that pulls water into the top layers of the skin.
  • This improves hydration and strengthens the skin barrier, making skin healthier and less likely to get irritated.
  • Though the study focused on dry skin, this benefit also applies to skin care in general.

Safety Profile:

  • No adverse effects were reported.
  • Glycerin was well tolerated, even by people with sensitive skin.

Clinical Relevance for Acne Treatment:

  • While not about acne, the findings are important for acne care.
  • Many acne treatments dry out the skin and damage its barrier.
  • Glycerin hydrates, calms irritation, and strengthens the barrier, which can reduce side effects like dryness and flaking.
  • This helps people stick to their acne treatments and keeps skin healthier overall.

Source: Caratelli, L., Smith, H., & Friscia, D. (2023). 42021 Glycerin-based Leave-on Products Provide Fast-acting Hydration in People with Moderate Skin Dryness. Journal of the American Academy of Dermatology, 89(3), AB171. DOI: 10.1016/j.jaad.2023.07.693

Chamomile Extract

  • Efficacy of two plant extracts against acne vulgaris: Initial results of microbiological tests and cell culture studies

  • A Comprehensive Study of Therapeutic Applications of Chamomile

Key Findings

  • This lab study tested two plant extracts (AE1 and AE2) against Propionibacterium acnes, the bacteria involved in acne.
  • Researchers also studied how the extracts affected gene activity in skin cells grown in the lab (HaCaT cells).
  • AE1 was a mix of walnut husk, myrtle leaves, chamomile flowers, stinging nettle leaves, and rose flowers.
  • No human clinical trials were conducted.

Quantitative Results with Statistical Significance:

  • Both extracts had strong antibacterial effects, with MIC values below 1/2048 µg/mL.
  • AE1 significantly:
  • Increased TNFα levels (1.1719, P < 0.0001), which suggests immune activity.
  • Decreased IL-1α (0.0588, P = 0.0231), reducing inflammation.
  • Decreased SRD5A1 (0.3081, P = 0.0351), which may help lower sebum production.
  • Overall, results suggest antibacterial, anti-inflammatory, and sebum-regulating benefits.

Mechanism of Action:

  • Chamomile extract (Chamomilla Recutita) in the mix helps fight bacteria and calm inflammation.
  • It reduces IL-1α, a key inflammatory signal in acne.
  • Lower SRD5A1 suggests less sebum (oil) production, which can help prevent clogged pores.

Safety Profile:

  • This study did not test safety in humans.
  • However, chamomile is widely used on the skin and is generally considered safe and soothing.

Clinical Relevance for Acne Treatment:

  • The results show that chamomile extract, especially combined with other plants, could help treat acne.
  • Its ability to kill acne bacteria, reduce inflammation, and possibly control oil makes it a strong candidate for acne products.
  • These lab findings support its use in skincare, but human studies are needed to confirm how well it works in real life.

Source: Kılıç, S., Öktem Okullu, S., Kurt, Ö., Sevinç, H., Dündar, C., Altınordu, F., & Türkoğlu, M. (2019). Efficacy of two plant extracts against acne vulgaris: Initial results of microbiological tests and cell culture studies. Journal of Cosmetic Dermatology, 18(4), 1061-1065. DOI: 10.1111/jocd.12814

Key Findings

  • This is a review article that summarizes many studies on chamomile.
  • It covers chamomile’s benefits, including anti-inflammatory, antioxidant, pain-relieving, and antimicrobial effects.
  • The review includes lab (in vitro) and animal (in vivo) research.

Quantitative Results with Statistical Significance:

  • Chamomile has important compounds like flavonoids, terpenoids, and coumarins that give it medicinal properties.
  • German chamomile (Matricaria chamomilla L.) has stronger effects than other chamomile types.
  • While it doesn’t give specific acne data, the review supports chamomile’s ability to reduce inflammation and fight bacteria, which are both helpful for acne.

Mechanism of Action:

  • Anti-inflammatory effects come mainly from chamazulene and bisabolol, which block inflammation signals in the skin.
  • Antimicrobial properties help fight bacteria linked to acne.
  • Antioxidants in chamomile protect skin from damage caused by oxidative stress.

Safety Profile:

  • Chamomile is generally safe to use on the skin and has a long record of use in traditional medicine.

Source: Sah, A., Naseef, P. P., Kuruniyan, M. S., Jain, G. K., Zakir, F., & Aggarwal, G. (2022). A Comprehensive Study of Therapeutic Applications of Chamomile. Pharmaceuticals, 15(10), 1284. DOI: 10.3390/ph15101284

Sunflower Seed Oil

  •  Anti-Inflammatory and Skin Barrier Repair Effects of Topical Application of Some Plant Oils

  • Sunflower Oil for Skin: Benefits, Limits, and How to Use It

Key Findings

  • This review article looked at how different plant oils, including sunflower seed oil, affect skin health.
  • It combined results from human studies, animal research, and lab tests.
  • The review focused on benefits like reducing inflammation, fighting oxidation, healing wounds, and repairing the skin barrier.

Quantitative Results with Statistical Significance:

  • Sunflower seed oil is rich in linoleic acid, which is important for keeping the skin barrier strong.
  • Studies showed that applying sunflower oil can reduce water loss through the skin (TEWL) by 33–50% and improve hydration.
  • Although the review didn’t focus specifically on acne, these skin benefits are well proven.

Mechanism of Action:

  • Linoleic acid in sunflower oil helps build ceramides, which keep the skin barrier healthy.
  • A stronger barrier prevents moisture loss and blocks irritants.
  • Sunflower oil also has anti-inflammatory effects that calm redness and irritation.
  • It is non-comedogenic, so it won’t clog pores, making it safe for acne-prone skin.

Safety Profile:

  • Sunflower seed oil is generally safe and well-tolerated.
  • It’s especially helpful for sensitive or damaged skin because it strengthens and protects the skin barrier.

Clinical Relevance for Acne Treatment:

  • Sunflower seed oil is useful in acne products because it supports the skin barrier and reduces inflammation.
  • Acne treatments often dry and irritate the skin, so sunflower oil can help keep it hydrated and calm.
  • Because it doesn’t clog pores, it’s a good choice for people with acne-prone skin.

 

Source: Lin, T. K., Zhong, L., & Santiago, J. L. (2017). Anti-Inflammatory and Skin Barrier Repair Effects of Topical Application of Some Plant Oils. International Journal of Molecular Sciences, 19(1), 70. DOI: 10.3390/ijms19010070

Key Findings

  • This article brings together findings from different studies and expert opinions about sunflower oil for skin.
  • It mentions a small study with 19 people comparing sunflower oil and olive oil, plus an animal study on wound healing.

Quantitative Results with Statistical Significance:

  • Sunflower oil is non-comedogenic (doesn’t clog pores), absorbs easily, and hydrates well.
  • The small human study showed sunflower oil was better than olive oil at keeping skin hydrated and protecting the skin barrier.
  • Linoleic acid in sunflower oil helps reduce inflammation when applied to skin.

Mechanism of Action:

  • Sunflower oil has linoleic acid, oleic acid, vitamin E, and sesamol.
  • Linoleic acid supports the skin barrier and keeps moisture in, while calming inflammation.
  • Vitamin E acts as an antioxidant, protecting skin from damage.
  • Because it’s non-comedogenic, it’s unlikely to clog pores.

Safety Profile:

  • Sunflower oil is usually safe and gentle for most people.
  • People with ragweed or sunflower seed allergies should be cautious, as they may react.

Clinical Relevance for Acne Treatment:

  • Sunflower oil is great for acne-prone skin because it won’t block pores.
  • Its linoleic acid content helps calm redness and irritation.
  • It keeps the skin barrier strong and hydrated, which is important when using drying acne treatments.
  • The antioxidants in sunflower oil also help support overall skin health, making it a gentle, effective ingredient for acne care.

Source: Whelan, C. (2019, August 7). Sunflower Oil for Skin: Benefits, Limits, and How to Use It. Healthline. https://www.healthline.com/health/sunflower-oil-for-skin

Caprylic Triglyceride

  • Anti-bacterial and anti-inflammatory properties of capric acid against Propionibacterium acnes: A comparative study with lauric acid

  • The Science of Caprylic/Capric Triglyceride in Skin Care

Key Findings

  • This study tested how capric acid and lauric acid fight Propionibacterium acnes, the bacteria linked to acne.
  • Experiments were done in lab-grown human skin cells (sebocytes and immune cells) and in mice with bacteria-induced ear swelling.
  • No human participants were involved.

Quantitative Results with Statistical Significance:

  • Both acids killed P. acnes bacteria.
  • Lauric acid was stronger at fighting bacteria than capric acid.
  • Both significantly lowered IL-6 and IL-8 (inflammatory signals) in skin cells.
  • In immune cells, both reduced IL-8 and TNF-α, which cause inflammation.
  • In mice, both acids reduced swelling and microabscesses caused by the bacteria.

Mechanism of Action:

  • These fatty acids likely work by blocking NF-κB activation and MAP kinase activity, which are pathways that trigger inflammation when P. acnes is present.

Safety Profile:

  • The study didn’t test safety in people.
  • However, fatty acids like capric acid are generally known to be safe for topical skincare.

Clinical Relevance for Acne Treatment:

  • While this research focused on isolated fatty acids, it suggests capric acid has antibacterial and anti-inflammatory effects that could help with acne.
  • Ingredients with capric acid may help lower bacteria and inflammation, improving acne symptoms.
  • More studies in humans are needed to confirm these benefits when used in acne treatments.

Source: Huang, W. C., Tsai, T. H., Chuang, L. T., Li, Y. Y., Zouboulis, C. C., & Tsai, P. J. (2014). Anti-bacterial and anti-inflammatory properties of capric acid against Propionibacterium acnes: A comparative study with lauric acid. Journal of Dermatological Science, 73(3), 232-240. DOI: 10.1016/j.jdermsci.2013.10.010

Key Findings

  • This is an informational article that reviews what is already known about Caprylic/Capric Triglyceride in skincare.
  • It does not report new studies or involve new participants.

Quantitative Results with Statistical Significance:

  • The article states that Caprylic/Capric Triglyceride is non-comedogenic, so it usually doesn’t clog pores.
  • It creates a protective layer on the skin to lock in moisture, which is helpful for dry or sensitive skin.
  • It also has antioxidant benefits.

Mechanism of Action:

  • This ingredient comes from coconut oil and glycerin.
  • It works as an emollient, forming a light, non-greasy barrier that helps keep moisture in by reducing water loss.
  • Its fatty acids help neutralize free radicals (antioxidant action).
  • Because of its structure, it’s less likely to block pores compared to heavier oils.

Safety Profile:

  • Caprylic/Capric Triglyceride is generally safe and well-tolerated by most skin types, including sensitive and acne-prone skin.
  • It has very low risk of irritation or allergic reaction unless someone has a severe coconut allergy.

Clinical Relevance for Acne Treatment:

  • This ingredient is especially useful in acne skincare because it moisturizes without clogging pores.
  • Acne treatments often dry out and irritate skin; this helps protect the skin barrier and prevent moisture loss.
  • Its soothing and antioxidant effects also support overall skin health, making it a good choice for acne-friendly moisturizers and creams.

Source: Skin Type Solutions. (2024, December 23). The Science of Caprylic/Capric Triglyceride in Skin Care. Retrieved from https://skintypesolutions.com/blogs/skincare/caprylic-capric-triglyceride

Caprylyl Glycol

  • What’s Caprylyl Glycol? Uses, Safety, and More

  • Antimicrobial, Preservative, and Hazard Assessments from Eight Chemical Classes

Key Findings

  • This is an informational article that reviews expert opinions and existing research about caprylyl glycol.
  • It is not based on a new research study.

Mechanism of Action:

  • Caprylyl glycol works in several ways:
  • Acts as a humectant, pulling moisture into the skin to keep it hydrated and smooth.
  • Functions as an emollient, softening the skin and helping maintain a healthy barrier.
  • Has antimicrobial effects, stopping bacteria growth in products and extending shelf life.
  • Improves the texture and spreadability of skincare formulas.

Safety Profile:

  • Generally safe for most skin types at the low levels used in skincare.
  • A 2012 safety review confirmed it is safe.
  • Because it can help other ingredients absorb better, careful formulation is important.
  • People with sensitive skin may want to patch test first.

Clinical Relevance for Acne Treatment and Skin Complexion Improvement:

  • Caprylyl glycol helps keep skin hydrated and supports the barrier, which is important for acne-prone skin.
  • Good hydration can prevent excess oil production and reduce irritation.
  • Its antimicrobial properties may help limit acne-causing bacteria.
  • Because it doesn’t clog pores, it is suitable for acne-prone skin and can improve overall complexion.

Source: Healthline. (2021, September 29). What’s Caprylyl Glycol? Uses, Safety, and More. https://www.healthline.com/health/beauty-skin-care/caprylyl-glycol

Key Findings

  • This study tested 130 substances from eight chemical groups to see how well they fight germs and how safe they are for people and the environment.
  • Caprylyl glycol was included to evaluate its ability to act as a preservative against fungi (Aspergillus brasiliensis) and bacteria (Pseudomonas aeruginosa).

Quantitative Results with Statistical Significance:

  • Caprylyl glycol was one of only two substances that provided strong preservation in test products.
  • It balanced good antimicrobial action with better safety compared to many traditional preservatives.
  • The abstract didn’t include specific numbers just for caprylyl glycol, but it was considered a top-performing ingredient.

Mechanism of Action:

  • As an alcohol, caprylyl glycol likely kills microbes by damaging their cell membranes and quickly breaking down proteins.

Safety Profile:

  • Caprylyl glycol showed a safer toxicity profile compared to harsher preservatives like isothiazolinones and formaldehyde releasers.
  • This makes it a less hazardous option for skincare products.

Clinical Relevance for Acne Treatment and Skin Complexion Improvement:

  • Its antimicrobial effects can help reduce acne-causing bacteria and fungi on the skin.
  • Using it as a preservative helps keep acne treatments stable and effective over time.
  • Because it’s safer and less irritating than many older preservatives, it’s a good choice for sensitive, acne-prone skin.
  • This contributes to clearer, healthier-looking skin.

Source: Lynn, L., Scholes, R. C., Kim, J. H., Wilson-Welder, J. H., Orts, W. J., & Hart-Cooper, W. M. (2024). Antimicrobial, Preservative, and Hazard Assessments from Eight Chemical Classes. ACS Omega, 9(16), 17869–17877. https://pmc.ncbi.nlm.nih.gov/articles/PMC11044204/

Honey

  • Randomised controlled trial of topical kanuka honey for the treatment of acne

  • Honey: its medicinal property and antibacterial activity

Key Findings

  • This randomized controlled trial tested Honevo (90% kanuka honey and 10% glycerin) for treating facial acne.
  • 136 people aged 16–40 with moderate acne joined the study.
  • They were split into two groups: one used the honey product plus antibacterial soap, the other used antibacterial soap alone.
  • Everyone used the soap twice daily for 12 weeks.

Quantitative Results with Statistical Significance:

  • The main goal was to see how many people improved their acne score by 2 points or more after 12 weeks.
  • 7.6% of the honey group improved vs. 1.9% of the control group.
  • Odds ratio for improvement was 4.2, but the p-value was 0.17, meaning this was not statistically significant.
  • In short: adding the honey-glycerin product did not clearly outperform soap alone.

Mechanism of Action:

  • While this study didn’t prove the honey formula worked better, honey itself is known to:
  • Fight bacteria (antimicrobial)
  • Reduce inflammation
  • Help wounds heal
  • These effects come from honey’s high sugar content, low pH, hydrogen peroxide, and plant compounds.
  • Glycerin helps draw moisture into the skin (humectant).

Safety Profile:

  • No major side effects were reported.
  • Some people dropped out (15 from the honey group, 14 from the control group), but reasons were not fully explained.
  • Honey is generally safe when applied to the skin.

Clinical Relevance for Acne Treatment:

  • This study showed that adding kanuka honey and glycerin to antibacterial soap did not result in clear, better acne improvement.
  • While honey has known benefits, more high-quality studies are needed to prove it works better than standard treatments for acne.
  • This trial shows why it’s important to test natural products carefully before making treatment claims.

Source: Semprini, A., Braithwaite, I., Corin, A., Sheahan, D., Tofield, C., Helm, C., ... & Beasley, R. (2016). Randomised controlled trial of topical kanuka honey for the treatment of acne. BMJ Open, 6(2), e009448. DOI: 10.1136/bmjopen-2015-009448

Key Findings

  • This review article looked at many studies about the medicinal uses of honey.
  • It focused mainly on honey’s ability to fight bacteria and help wounds heal.

Quantitative Results with Statistical Significance:

  • Honey has strong antibacterial effects against many harmful bacteria.
  • In most honeys, this comes from hydrogen peroxide produced by enzymes.
  • Some honeys (like Manuka honey) still work well even without hydrogen peroxide because of their low pH and high sugar content.
  • Medical-grade honey has been shown in lab tests to kill antibiotic-resistant bacteria effectively.

Mechanism of Action:

  • Honey fights bacteria in several ways:
  • Makes hydrogen peroxide (which kills bacteria)
  • Has a low pH that stops bacteria from growing
  • Contains high sugar, drawing moisture out of bacteria (osmolarity)
  • Includes bioactive compounds that support healing
  • Honey is also thick, creating a protective layer over wounds.

Safety Profile:

  • Honey has been safely used for centuries as both food and medicine.
  • The review confirms it is generally safe for topical use.

Clinical Relevance for Acne Treatment:

  • Honey’s strong antibacterial effects can help fight Cutibacterium acnes, the bacteria involved in acne.
  • It also reduces inflammation and helps skin heal, which can calm red, irritated pimples and speed up recovery.
  • By keeping wounds moist, honey may help heal acne lesions faster and lower the risk of scarring.

Source: Mandal, M. D., & Mandal, S. (2011). Honey: its medicinal property and antibacterial activity. Asian Pacific Journal of Tropical Biomedicine, 1(2), 154–160. DOI: 10.1016/S2221-1691(11)60016-6

Ethylhexylglycerin

  • Ethylhexylglycerin Impairs Membrane Integrity and Enhances the Lethal Effect of Phenoxyethanol

Key Findings

  • This lab (in vitro) study looked at how ethylhexylglycerin (EHG) helps boost the bacteria-killing power of 2-phenoxyethanol (PE), a preservative.
  • The study used E. coli bacteria as a model.

Quantitative Results with Statistical Significance:

  • When combined, low doses of EHG (0.075%) and PE (0.675%) killed over 99.999% of the bacteria within 30 minutes.
  • EHG alone damaged bacterial membranes even at low levels.

Mechanism of Action:

  • EHG works by breaking down the bacterial cell membrane.
  • This damage causes the bacteria to leak important contents, disrupts their energy production, and changes their shape.
  • This makes other preservatives more effective.

Safety Profile:

  • The study focused on how well EHG kills bacteria, not on its safety for people.
  • EHG is widely used in cosmetics as a preservative booster.
  • There have been a few reports of contact allergies to EHG.

Clinical Relevance for Acne Treatment and Skin Complexion Improvement:

  • EHG’s strong antibacterial action can help fight Cutibacterium acnes, the bacteria that cause acne.
  • By reducing bacteria and inflammation, it can help prevent breakouts.
  • Because EHG helps other preservatives work better, products can use lower preservative levels, which may reduce irritation for acne-prone skin.
  • This supports healthier skin and a clearer complexion.

Source: Langsrud, S., Steinhauer, K., Lüthje, S., Weber, K., Goroncy-Bermes, P., & Holck, A. L. (2016). Ethylhexylglycerin Impairs Membrane Integrity and Enhances the Lethal Effect of Phenoxyethanol. PLoS ONE, 11(10), e0165228. https://pmc.ncbi.nlm.nih.gov/articles/PMC5082626/

1,2-Hexanediol

  • Food-grade antimicrobials potentiate the antibacterial activity of 1,2-hexanediol

  • The efficiency of humectants as skin moisturizers in the presence of oil

Key Findings

  • This lab (in vitro) study tested how well 1,2-hexanediol kills different types of bacteria.
  • It also looked at whether combining it with food-safe antimicrobials could make it work better.

Quantitative Results with Statistical Significance:

  • 1,2-hexanediol showed strong antibacterial effects against many bacteria, with effective concentrations (MICs) between 0.5–2% by volume.
  • To fully kill bacteria, concentrations only needed to be 1–2 times the MIC.
  • When combined with certain food-grade antimicrobials (like macelignan and octyl gallate), its effective concentration dropped by half or more against Gram-positive bacteria.

Mechanism of Action:

  • 1,2-hexanediol works by damaging bacterial cell membranes and disrupting their internal balance.
  • When mixed with other antimicrobials, it works even more effectively, showing a synergistic effect.

Safety Profile:

  • The study did not test safety on humans.
  • It noted that combining it with food-grade antimicrobials could be safe for use in cosmetics, suggesting it is considered safe in formulation when used properly.

Clinical Relevance for Acne Treatment and Skin Complexion Improvement:

  • The strong antibacterial properties are important for acne care because they help control Cutibacterium acnes, the bacteria that causes breakouts.
  • By reducing bacteria, 1,2-hexanediol can help lower inflammation and prevent new pimples.
  • Its broad-spectrum action also helps keep products stable and may support a healthier skin environment, contributing to clearer, calmer skin.

Source: Yogiara, S., Hwang, S. J., Park, S., Hwang, J. K., & Pan, J. G. (2015). Food-grade antimicrobials potentiate the antibacterial activity of 1,2-hexanediol. Letters in Applied Microbiology, 60(5), 431–439. https://pubmed.ncbi.nlm.nih.gov/25631558/

Key Findings

  • This study used guinea pigs to test how well different humectants, including 1,2-hexanediol, moisturize dry skin.
  • Dry skin was created by applying sodium lauryl sulfate.
  • Researchers tested the humectants mixed in either water or MCT oil.

Quantitative Results with Statistical Significance:

  • 1,2-hexanediol dissolved in MCT oil did not improve skin moisture.
  • When humectants like glycerol were mixed with water, they effectively treated dryness.
  • This shows that the type of base (water vs. oil) is very important for humectant performance.

Mechanism of Action:

  • 1,2-hexanediol attracts and holds water in the skin (humectant effect).
  • For it to work well, it needs to be in a formula that allows it to mix with water and reach the skin.

Safety Profile:

  • The study did not report any side effects from 1,2-hexanediol in guinea pigs.
  • However, it mainly looked at how well it worked, not safety.

Clinical Relevance for Acne Treatment and Skin Complexion Improvement:

  • Even though it didn’t show moisturizing effects in an oil base here, 1,2-hexanediol is still known as a humectant in skincare.
  • Good hydration is important for acne-prone skin to keep the skin barrier healthy and prevent extra oil production.
  • When used in the right formulation, 1,2-hexanediol can help keep skin hydrated, improve overall complexion, and reduce dryness caused by acne treatments.

Source: Sagiv, A. E., Dikstein, S., & Ingber, A. (2001). The efficiency of humectants as skin moisturizers in the presence of oil. Skin Research and Technology, 7(1), 32–35. https://pubmed.ncbi.nlm.nih.gov/11301638/

Chlorophyllin-Copper Complex

  • Assessment of the safety and efficacy of topical copper chlorophyllin in women with photodamaged facial skin

Key Findings

  • This pilot study took place at one center with 10 women who had mild to moderate wrinkles and sunspots (solar lentigines).
  • They applied a gel with 0.066% chlorophyllin complex salts on their eye area, cheeks, and nose twice a day for 8 weeks.

Quantitative Results with Statistical Significance:

  • After 8 weeks, all measured skin concerns—wrinkles, fine lines, and sunspots—improved significantly compared to baseline.
  • The product was well tolerated, and most participants were highly satisfied.

Mechanism of Action:

  • Chlorophyllin-copper complex comes from chlorophyll and has antioxidant and wound-healing effects.
  • It helps neutralize free radicals from sun exposure and may support skin repair.

Safety Profile:

  • No significant side effects were reported, suggesting it is safe for cosmetic use.

Clinical Relevance for Acne Treatment and Skin Complexion Improvement:

  • Although this study focused on sun-damaged skin, the improvements in skin tone and texture are relevant to acne-prone skin.
  • The antioxidant and healing properties can help calm inflammation and support healing of acne lesions.
  • This may lead to smoother skin and a healthier-looking complexion overall.

Source: Sigler, M. L., & Stephens, T. J. (2015). Assessment of the safety and efficacy of topical copper chlorophyllin in women with photodamaged facial skin. Journal of Drugs in Dermatology, 14(4), 401–404. https://pubmed.ncbi.nlm.nih.gov/25844615/