3beta,17alpha,21-Trihydroxy-5alpha-pregnan-20-one 5-alpha-Pregnan-20-one, 3-beta,17,21-trihydroxy- (8CI) 516-47-2 Allopregnane-3beta,17alpha,21-triol-20-one Compound P Pregnan-20-one, 3,17,21-trihydroxy-, (3-beta,5-alpha)- (9CI) REICHSTEIN'S SUBSTANCE P Substance P