Ampyrone increases pigmentation in a human 3D epidermal model, The top row shows visible epidermal darkening after treatment every other day with ampyrone for 21 days as compared to negative control. The bottom row shows magnification of epidermal cells revealing increased melanin synthesis in the ampyrone treated melanocytes as compared to negative control. Positive control is alpha-melanocyte stimulating hormone (αMSH) plus beta-fibroblast growth factor (βFGF). Photo by Dr.