Topical 8% glycolic acid and 8% L-lactic acid creams for the treatment of photodamaged skin. A double-blind vehicle-controlled clinical trial.

OBJECTIVE To evaluate the efficacy and tolerability of 2 widely used topical alpha-hydroxy acids at low concentrations, 8% glycolic acid and 8% lactic (L-isoform) acid creams, in the treatment of photodamaged skin. DESIGN A single-center, 22-week, double-blind, vehicle-controlled, randomized clinical trial assessed the overall severity of photodamage on the faces and forearms of volunteers, based on 7 individual clinical components of cutaneous photodamage. SETTING The study was performed in an outpatient clinical research unit at the Massachusetts General Hospital, Boston. PATIENTS Seventy-four women, aged 40 to 70 years, with moderately severe photodamaged facial skin were enrolled in the study. One subject withdrew from the study early because of skin irritation, and 6 subjects withdrew from the study for personal reasons. INTERVENTIONS Glycolic acid, L-lactic acid, or vehicle creams were applied twice daily to the face and outer aspect of the forearms. MAIN OUTCOME MEASURES Improvement in alpha-hydroxy acid-treated photodamaged skin as determined by patient self-assessments and physician evaluations of efficacy and irritancy. RESULTS The percentage of patients using either 8% glycolic acid or 8% L-lactic acid creams on the face achieving at least 1 grade of improvement (using a scale from 0 through 9) in overall severity of photodamage was significantly greater than with the vehicle cream (76% glycolic acid, 71% lactic acid, and 40% vehicle; P < .05). On the forearms, after 22 weeks, treatment with glycolic acid cream was superior to the vehicle in improving the overall severity of photodamage and sallowness (P < .05). L-Lactic acid cream was significantly superior to the vehicle in reducing the overall severity of photodamage (P < .05), mottled hyperpigmentation (P < .05), sallowness (P < .05), and roughness on the forearms (P < .05) at week 22. CONCLUSIONS Topical 8% glycolic acid and 8% L-lactic acid creams are modestly useful in ameliorating some of the signs of chronic cutaneous photodamage. These agents are well tolerated and available without prescription.