Topical Sandalore, a Specific OR2AT4-Stimulating Odorant, Ameliorates Telogen Effluvium: Randomized, Double-Blinded, Placebo-Controlled Trial

In a randomized, double-blinded, placebo-controlled trial involving 60 female volunteers with telogen effluvium, the application of a solution containing 1% Sandalore®, a synthetic sandalwood-like odorant that stimulates the olfactory receptor OR2AT4, was found to reduce hair shedding, increase hair volume, and increase the percentage of anagen (growth phase) hair follicles significantly more than a placebo. The placebo group used natural sandalwood oil, which has the same odor but does not stimulate OR2AT4. The trial lasted 24 weeks, and most effects were observed after 8 weeks and maintained at week 24. Hair thickness and density were not affected. Subjectively, individuals in the treatment group were more satisfied with their hair appearance and overall results. This study provided evidence that a cosmetic odorant can positively impact human hair growth in vivo and suggests the potential use of topical "olfactotherapy" with Sandalore as an adjunct therapy for hair disorders characterized by excessive hair shedding.