Safety Evaluation of Topical Valproate Application

In 2013, a safety evaluation was conducted on topical Valproate (VPA), a mood stabilizer suggested to stimulate hair regrowth, involving 20 healthy volunteers aged 21 to 43 years. Cell viability tests on HaCaT keratinocytes, fibroblasts, and RBL-3H mast cells showed no toxicity from VPA. A clinical patch test and a skin irritation test using microneedle rollers for transdermal drug delivery were also performed, with only one patient showing minimal erythema at 1 hour, which disappeared within a few hours. No significant findings were obtained in the clinical patch test. The study concluded that VPA has minimal potential to cause skin irritation and can be safely applied to human skin.