Topical tretinoin: What It Is, Uses, Evidence & Safety

At a glance

Purpose, evidence and practical considerations.

What it’s for

Acne treatment and selected photoageing concerns

What the evidence says

Evidence supports acne treatment and improvement in some signs of sun-related skin ageing. It is not a treatment for whole-body ageing, and irritation limits use for some people.

Confidence: strong

Clinical safety

Irritation, dryness, peeling and photosensitivity are common. Avoid eyes and damaged skin, use sun protection, and review pregnancy plans with a prescriber. Strengths and vehicles are not interchangeable, and more irritation is not more benefit.

How it works & important distinctions

Tretinoin binds nuclear retinoic-acid receptors and changes epidermal differentiation and collagen-related signalling. Effects and irritation depend on vehicle, concentration, frequency and sun exposure.

Regulatory status: FDA-approved topical prescription medicine for acne; some formulations have evidence for photodamaged skin but product indications vary

Different forms

The evidence on this page does not automatically apply to:

oral isotretinoin
retinol cosmetics
adapalene
tazarotene

In these protocols

How people use it, with their schedules, context and original sources.

Bryan JohnsonPrescriptions

Date of record:: 23 Jan 2026

0.025–0.1% · nightly
skin age reversal

Details & sources

The living protocol lists 0.025–0.1%; the June evening routine confirms nightly use but does not state a strength.

Common dose and timing

Dose and schedule patterns reported in public protocols; these are observations, not prescribing advice. Private and hidden usage is excluded.

Dose

0.025–0.1%1 public entry

Frequency

nightly1 public entry

Other items in these protocols

These share a protocol with this intervention. This does not establish that they work together or are suitable alternatives.