Does prostaglandin D₂ hold the cure to male pattern baldness?

Lipids in the skin are the most diverse in the entire human body. Their bioactivity in health and disease is underexplored. Prostaglandin D₂ has recently been identified as a factor which is elevated in the bald scalp of men with androgenetic alopecia (AGA) and has the capacity to decrease hair lengthening. An enzyme which synthesizes it, prostaglandin D₂ synthase (PTGDS or lipocalin-PGDS), is hormone responsive in multiple other organs. PGD₂ has two known receptors, GPR44 and PTGDR. GPR44 was found to be necessary for the decrease in hair growth by PGD₂. This creates an exciting opportunity to perhaps create novel treatments for AGA, which inhibit the activity of PTGDS, PGD₂ or GPR44. This review discusses the current knowledge surrounding PGD₂, and future steps needed to translate these findings into novel therapies for patients with AGA.