Prostaglandin D2(PGD2); prostaglandin D2 receptor (CRTH2; GPR44; CD294); prostaglandin D2 synthase (PTGDS)

Mouse and human studies indicated that inhibiting prostaglandin D2 (PGD2) signaling could be a potential treatment for androgenetic alopecia. The studies found that balding scalp areas in males had higher levels of PGD2 protein compared to areas with hair. Both mouse and human scalp experiments showed that PGD2 inhibited hair follicle growth when compared to a control vehicle. Future research steps involve exploring whether blocking prostaglandin D2 synthase (PTGDS) or the prostaglandin D2 receptor (GPR44) could enhance hair growth. Additionally, at least nine companies were reported to have GPR44 antagonists in Phase II trials or earlier stages of development for treating allergies or asthma. A patent application had been filed and the findings were available for licensing.