A Study of Botulinum Toxin A for Ultraviolet-Induced Hyperpigmentation: A Randomized Controlled Trial.

Background: Ultraviolet (UV) exposure contributes to skin hyperpigmentation. Recently, botulinum neurotoxin type A (BoNT-A) showed a promising protective effect on UVB-induced hyperpigmentation in both in vitro and animal models.

Objective: The study aimed to investigate the preventive effect of BoNT-A against UVB-induced hyperpigmentation in human subjects.