Fasedienol (INNTooltip International Nonproprietary Name; developmental code names PH94B and Aloradine), also known as 4-androstadienol or as 4,16-androstadien-3β-ol, is a pherine which is under development by VistaGen Therapeutics[1][2] in a nasal spray formulation (PRN) for the acute treatment of social anxiety disorder.

As of 2020, it is in phase III clinical trials for social anxiety disorder.

[12] Fasedienol lacks affinity for steroid hormone receptors and has instead been found to directly activate isolated human vomeronasal receptor cells at nanomolar concentrations (EC50 = 200 nM).

[8] The closely related pheromone androstenol (5α-androst-16-en-3α-ol) has been found to act as a potent positive allosteric modulator of the GABAA receptor, and it has been proposed that this action may mediate its pheromone effects.

[13] As fasedienol is very closely related structurally to androstadienol, it might be converted into androstenol similarly and hence potentiation of the GABAA receptor could contribute to its mechanism of action.