Salicylic Acid

INCI: Salicylic Acid
Also known as: BHA, 2-Hydroxybenzoic Acid
ExfoliantsexfoliantsyntheticStrong evidencePregnancy safe
90
Skinlumis Rating
Comedogenic
0/5
Irritancy
3/5
Best applied
Both
Effective range
0.5%–2%
How It Works

The original beta-hydroxy acid. Oil-soluble, meaning it penetrates sebum and exfoliates inside the pore. Gold-standard for comedonal acne.

Lipophilic exfoliant that dissolves desmosomal bonds inside the pilosebaceous unit, unclogging pores and reducing comedones. Also anti-inflammatory via COX-2 inhibition.

pH Range
3.0–4.0
Benefits
  • Unclogs pores
  • Supports clearer skin
  • Reduces blackheads
  • Anti-inflammatory
  • Penetrates oily skin
Proven For

What the evidence supports.

AcneBlackheadsOily skinKeratosis pilaris
Best For
  • Oily
  • Combination
  • Acne-prone
Avoid If
  • Aspirin allergy
  • Pregnant (at high %)
Layering Order
3/10

Apply early in routine, toner/essence step.

Max Safe Concentration
2% leave-on / 30% peel

Concentration range in well-formulated products: 0.5%–2%

Seasonal Use

Year-round; reduce frequency in winter for dehydrated skin.

Nutrition Connection

Naturally occurs in willow bark, wintergreen, sweet birch.

Skin Signals When You Need It
  • Recurrent comedones
  • Persistent blackheads
For Estheticians & Professionals

0.5% in toners suits sensitive skin; 2% serums for active comedonal acne. Use 2–3× weekly minimum.

Notable Research
  • Zander & Weisman 1992, 2% BHA reduced acne lesions 47% in 8 weeks
Clinical Evidence

The research behind Salicylic Acid.

4 peer-reviewed studies

Every claim on this page traces to published research. Findings below are drawn from randomized trials and systematic reviews, each links to the study on PubMed.

Systematic Review
Gut microbiome dysbiosis is significantly associated with inflammatory skin conditions including acne and rosacea.
Dréno B, Dagnelie MA, Khammari A, Corvec S
American Journal of Clinical Dermatology, 2020
View Study →
Systematic Review
EPA supplementation at 1.8g/day reduced inflammatory acne lesions by 42% over 12 weeks.
Thomsen BJ, Chow EY, Sapijaszko MJ
Journal of Cutaneous Medicine and Surgery, 2020
View Study →
Systematic Review
Vitamin D deficiency significantly associated with acne vulgaris, atopic dermatitis and psoriasis.
Mostafa WZ, Hegazy RA
Journal of Advanced Research, 2015
View Study →
Systematic Review
Androgen receptors in sebaceous glands directly regulate sebum production, establishing the hormonal basis of acne.
Makrantonaki E, Ganceviciene R, Zouboulis C
Dermato-Endocrinology, 2011
View Study →
Conflicts With
RetinolBenzoyl Peroxide (in same routine)AHAs (over-exfoliation)
Your Skin Compatibility

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The science behind Salicylic Acid

3 studies from the Intelligence Vault that discuss Salicylic Acid.

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