Lactic acid and glycolic acid creams for sun-damaged skin

Seventy-four women aged 40 to 70 with moderately severe sun damage applied 8% glycolic acid, 8% L-lactic acid, or an identical cream with no acid in it, twice a day for 22 weeks. Nobody — including the assessors — knew which cream was which. On the face, 71% of the lactic acid group improved by at least one grade on a nine-point scale, compared with 76% for glycolic acid and 40% for the plain cream. On the forearms, lactic acid was better than the plain cream for overall severity, blotchy pigmentation, sallowness and roughness. Only one person dropped out because of irritation. This remains the best-quality trial of lactic acid for sun-damaged skin, and it is thirty years old. The authors described the benefit as modestly useful, which is a fair summary.