Acne Ingredients
18Acne is caused by excess sebum, clogged pores, bacterial overgrowth (C. acnes), and inflammation. The most effective treatments target multiple causes simultaneously. Mild acne responds to topical treatments; moderate-to-severe acne may require prescription-strength ingredients or combinations.
Adapalene
A third-generation synthetic retinoid originally developed for acne that has significant anti-aging benefits. Adapalene is more stable than tretinoin (resistant to light and oxygen degradation) and better tolerated because it selectively binds to RAR-beta and RAR-gamma receptors rather than all three subtypes. The 0.1% concentration became available OTC in 2016 (Differin), making it the most accessible prescription-strength retinoid.
Adapalene
A third-generation synthetic retinoid specifically designed for acne treatment. Unlike tretinoin, adapalene selectively binds RAR-beta and RAR-gamma receptors in the skin, providing potent comedolytic and anti-inflammatory effects with significantly less irritation. It is also more stable in light and with benzoyl peroxide. Differin (0.1%) became OTC in 2016 — the first retinoid available without prescription in the US.
Azelaic Acid
A dicarboxylic acid naturally produced by yeast on the skin. Azelaic acid is a true multi-tasker that treats acne, rosacea, and hyperpigmentation simultaneously. It is one of the few active ingredients considered safe during pregnancy, and it uniquely targets only abnormal melanocytes — meaning it brightens dark spots without lightening normal skin. Effective for both inflammatory acne and post-inflammatory hyperpigmentation (PIH).
Azelaic Acid
A dicarboxylic acid naturally produced by Malassezia yeast on human skin. Azelaic acid is a uniquely versatile ingredient — it treats acne, reduces hyperpigmentation, has anti-rosacea effects, and is safe in pregnancy. It selectively targets abnormally active melanocytes while leaving normal pigmentation alone, making it ideal for post-inflammatory hyperpigmentation. Also available by prescription (15-20%) for rosacea.
Benzoyl Peroxide
The most effective OTC acne treatment and one of the few topical treatments that kills acne-causing bacteria (C. acnes) without promoting antibiotic resistance. Benzoyl peroxide works through oxidation — it releases oxygen into pores, creating an environment where anaerobic bacteria cannot survive. It is one of three first-line acne treatments (alongside adapalene and salicylic acid) recommended by dermatological guidelines.
Benzoyl Peroxide
The most widely used OTC acne treatment and one of the only topical anti-acne agents to which bacteria cannot develop resistance. Benzoyl peroxide kills C. acnes through oxidative damage — releasing free oxygen radicals that the anaerobic bacteria cannot survive. It also has mild keratolytic and comedolytic (pore-unclogging) effects. Available in 2.5%, 5%, and 10% concentrations.
Green Tea Extract (EGCG)
Epigallocatechin gallate (EGCG) is the primary polyphenol in green tea and one of the most potent topical antioxidants. It has been shown to reduce UV damage, decrease sebum production, reduce inflammation, and inhibit the enzymes that break down collagen and elastin. Green tea extract is one of the few antioxidants with evidence for both topical and oral skin benefits.
Hemp Seed Oil
Cold-pressed from Cannabis sativa seeds, hemp seed oil has an ideal 3:1 ratio of omega-6 to omega-3 fatty acids — the ratio considered optimal for skin health. It is rich in linoleic acid (which acne-prone skin is deficient in), gamma-linolenic acid (GLA, a potent anti-inflammatory), and natural vitamin E. Does not contain THC or CBD. One of the best oils for acne-prone, inflamed, or eczema-prone skin.
Mandelic Acid
The gentlest AHA, derived from bitter almonds. Mandelic acid has the largest molecular size of commonly used AHAs (152 Da), giving it the slowest skin penetration and the least irritation potential. It is also lipophilic (partially oil-soluble), giving it some ability to penetrate pores — a property unique among AHAs. Especially effective for acne-prone skin with hyperpigmentation, and safe for darker skin tones.
Mandelic Acid
An alpha-hydroxy acid (AHA) derived from bitter almonds with a molecular weight nearly double that of glycolic acid (152 Da vs 76 Da). This larger molecule penetrates more slowly and evenly, making mandelic acid the gentlest AHA with the least irritation potential. It is also lipophilic, giving it mild antibacterial properties similar to salicylic acid. Excellent for acne-prone, sensitive, and melanin-rich skin types.
Niacinamide
A true multitasker — niacinamide (vitamin B3) addresses almost every skin concern simultaneously. It strengthens the skin barrier by boosting ceramide production, reduces hyperpigmentation by inhibiting melanosome transfer, controls sebum production, minimizes pore appearance, reduces redness, and has anti-aging benefits. One of the most versatile and well-tolerated actives in skincare.
Propolis
A resinous substance produced by honeybees from tree buds, used to seal and protect the hive. Propolis contains over 300 bioactive compounds including flavonoids, phenolic acids, and caffeic acid phenethyl ester (CAPE). In skincare, it provides potent anti-inflammatory, antimicrobial, and wound-healing effects. Popular in Korean skincare for acne-prone and sensitive skin.
Retinaldehyde
The immediate precursor to retinoic acid, sitting between retinol and tretinoin in both potency and the conversion chain. Retinaldehyde requires only one enzymatic step to become active (vs two for retinol), making it significantly more effective than retinol while remaining available OTC. It also has direct antibacterial activity against C. acnes — unique among retinoids.
Salicylic Acid
The only beta-hydroxy acid (BHA) used in skincare. Salicylic acid is oil-soluble, meaning it can penetrate into pores and dissolve the sebum and dead skin that cause blackheads and acne. This makes it fundamentally different from AHAs (which only work on the skin surface). It also has direct anti-inflammatory properties, reducing the redness and swelling of acne lesions.
Sulfur
One of the oldest acne treatments, used for centuries. Sulfur has keratolytic (exfoliating), antimicrobial, and anti-inflammatory properties that make it effective for acne, seborrheic dermatitis, and rosacea. It has a distinctive smell but is gentler than benzoyl peroxide and works well for people who cannot tolerate BP or salicylic acid. Often found in traditional 'sulfur soap' and spot treatments.
Tea Tree Oil
An essential oil from Melaleuca alternifolia with broad-spectrum antimicrobial and anti-inflammatory properties. 5% tea tree oil has been shown in clinical trials to be as effective as 5% benzoyl peroxide for inflammatory acne, with fewer side effects (though slower onset). It is the most evidence-backed essential oil in dermatology. Must be used diluted — pure tea tree oil can cause severe irritation.
Tretinoin
The gold standard anti-aging ingredient with the most clinical evidence of any topical. Tretinoin (all-trans retinoic acid) is the active form of vitamin A that directly binds to retinoic acid receptors in skin cells. It accelerates cell turnover, stimulates collagen synthesis, reduces fine lines and wrinkles, fades hyperpigmentation, and improves skin texture. Prescription-only in most countries.
Witch Hazel
An astringent extract from Hamamelis virginiana bark and leaves with anti-inflammatory and antioxidant properties. Traditional uses include treating acne, reducing pore appearance, and soothing irritated skin. However, many commercial witch hazel toners contain high concentrations of alcohol that can dry and damage the skin barrier. Alcohol-free witch hazel is the preferred form for skincare.