Pregnanetriol is a steroid metabolite of progesterone. Elevated levels of pregnanetriol in urine indicate a disruption of adrenal steroidogenic pathways.

Prostaglandin F1 alpha is a stable metabolite of prostacyclin, a powerful inhibitor of platelet aggregation as well as a potent vasodilator. Prostaglandin F1a is derived mainly from prostaglandin E1 and is metabolized to 6-keto prostaglandin F1a. It was shown, that the fluctuating prostaglandin F1 alpha levels were of clinical significance in the management of vasomotor tone and platelet function, common problems in the care and the prevention of hemorrhage in critically ill infants.

4-Piperidinol, 1-phenethyl-4-phenyl acetate (PEPAP) is a synthetic opioid discovered by Janssen in 1960. PEPAP is an analog of meperidine, it is abused and illegally sold on streets as a "synthetic heroin".