 A positional isomer of androstenol, 3β-androstenol (5α-androst-16-en-3β-ol), is also endogenous to humans (as well as to pigs), behaving as a pheromone and contributing to axillary odor.In humans and boars, androstenol is biosynthesized in the testes.Pregnenolone is metabolized into androstadienol by the 16-ene-synthetase activity of CYP17A1.