Treatment of androgenetic alopecia with 5-aminolevulinic acid photodynamic therapy: A randomized, placebo-controlled, split-scalp study of efficacy and safety

Abstract

Background and objectivesAndrogenetic alopecia (AGA) is one of the most common hair loss disorders. Treatment options for AGA are limited . New therapies for AGA are clinically needed. 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is widely applied in diseases involving the pilosebaceous unit. However, limited research has explored the efficacy of ALA-PDT in treating alopecia. Some studies reported hair regrowth after PDT in alopecia areata patients, but the efficacy of ALA-PDT on AGA remains unclear. The objective of this study is to evaluate the efficacy and safety of ALA-PDT for the treatment of AGA. MethodsA randomized, placebo-controlled, split-scalp clinical study was conducted. Subjects with AGA received six sessions of 5% ALA-PDT on one half of their scalp and the red-light therapy on the other half. The treatments were applied every two weeks for six sessions on each subject. ResultsThere were 7 subjects enrolled in this study. No significant difference in hair density was observed between the red-light treatment and ALA-PDT treatment. The hair density in the ALA-PDT treated half of the scalp significantly decreased 1 week after the treatment, then it increased, and no statistical difference was found at 12 weeks after the last treatment compared to the baseline. There was no significant improvement in hair growth according to a 7-point scale and the subjects’ self-assessments. The main adverse effects in ALA-PDT treatment were mild edema and tolerable pain, and no adverse effect was observed in red-light treatment. Conclusions6 sessions of 5% ALA-PDT did not increase the hair growth of AGA patients, but slightly suppressed the sebum secretion on the scalp. The adverse effects of ALA-PDT were mild, which indicated safety and tolerability of this treatment.