Prescription Retinoid

Tretinoin

Tretinoin (all-trans retinoic acid) is the most studied topical anti-ageing ingredient in dermatology. It is the active form of vitamin A — no conversion required — and has strong evidence for reducing wrinkles, improving skin texture, treating acne, and reversing photoageing.

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Strong Evidence

Last reviewed: March 2026 · Our methodology

What It Does

Tretinoin binds directly to retinoic acid receptors (RARs) in the nucleus of keratinocytes and fibroblasts, modulating gene expression. Unlike retinol, which requires two enzymatic conversion steps to become active, tretinoin is the final active form — this makes it faster-acting and more potent, but also more irritating.

Key mechanisms: accelerates epidermal turnover (normalising the skin’s shedding cycle), stimulates collagen I and III synthesis in the dermis, reduces collagen-degrading MMP expression, increases glycosaminoglycan (GAG) content for improved hydration, disperses melanin for pigmentation improvement, and normalises follicular keratinisation (the primary mechanism in acne).

Tretinoin has been continuously studied since the 1960s. It is the most extensively validated topical ingredient in dermatology for both acne and photoageing.

Best Use Cases

Photoageing (fine lines, wrinkles, rough texture, mottled pigmentation)
Acne (comedonal and inflammatory — first-line prescription topical)
Post-inflammatory hyperpigmentation
Skin texture and pore appearance improvement
Actinic keratoses (adjunctive use)

Who May Benefit Most

Adults with moderate-to-severe photoageing, persistent acne not responding to OTC retinoids, or those seeking the most evidence-backed anti-ageing topical available. Requires prescription in most countries.

Cautions

Tretinoin causes significant irritation during the retinisation period (typically 4–12 weeks): dryness, peeling, redness, stinging, and increased sun sensitivity. Start at the lowest concentration (0.025%) every other night. Always use sunscreen. Absolutely contraindicated in pregnancy (teratogenic — FDA category X). Not recommended while breastfeeding. Can cause purging (temporary acne worsening) in the first 4–8 weeks.

Common Mistakes

Starting at too high a concentration (0.05% or 0.1%) without building tolerance
Applying to damp skin (increases penetration and irritation)
Using too much product — a pea-sized amount covers the entire face
Combining with other irritating actives (AHA, BHA, benzoyl peroxide) during the adjustment period
Abandoning treatment during the purge period (weeks 2–6)
Skipping sunscreen — tretinoin increases UV sensitivity significantly
Not buffering with moisturiser when starting (apply moisturiser first, then tretinoin over it)

Combines Well With

Niacinamide (reduces irritation and supports barrier)
Hyaluronic acid and ceramides (hydration and barrier support during retinisation)
Sunscreen (non-negotiable)
Azelaic acid (on alternate nights for pigmentation and acne)

May Combine Poorly With

AHA/BHA exfoliants in the same PM routine (use on non-tretinoin nights)
Benzoyl peroxide at the same time (may degrade tretinoin — use AM/PM split)
Vitamin C at low pH in the same step (potential irritation stacking — use vitamin C in AM)
Other prescription retinoids (never combine)

Realistic Timeline

Acne: initial purging weeks 2–6, significant improvement by 8–12 weeks, optimal results at 3–6 months. Anti-ageing: texture improvements at 8–12 weeks, wrinkle reduction at 6–12 months, continued improvement up to 2 years of use. Tretinoin is a long-term commitment — benefits are cumulative and reversible if stopped.

Disclaimer

Tretinoin is a prescription medication. This information is educational. Consult a dermatologist for a prescription, appropriate concentration, and personalised guidance. Contraindicated in pregnancy.