Tretinoin

What the evidence says

Tretinoin is one of the better-supported topical treatments for photoaged skin. Two systematic reviews of randomized vehicle-controlled trials found improvements in fine wrinkles and other clinical signs, although formulations, concentrations, follow-up periods, and outcome scales varied.^[1][2]

Individual trials support both short- and long-term effects. A 24-week multicenter trial of 0.05% cream found greater improvement than vehicle in wrinkles, mottled pigmentation, lentigines, laxity, and roughness; a two-year trial found sustained clinical improvement and increased a marker of procollagen synthesis without the histologic harms it monitored.^[4][3]

The effect is gradual rather than restorative in the literal sense. Prescribing information describes improvement over months and presents tretinoin as an adjunct to comprehensive sun avoidance and skin care; continued use may be needed to maintain benefit.^[5]

The Strong rating applies specifically to visible facial photoaging, not lifespan or whole-body aging. Irritation is common, participants in the trial literature were predominantly women, and the evidence does not identify one concentration or regimen as best for every person.^[1][2][5]