Summary.

This review focuses on the chemistry and biomolecular mechanisms of action of several tryptamine derivatives. The substances chosen are of great biological importance. Serotonin and melatonin are both neurohormones, strongly interconnected metabolically. They regulate sleep, apetite, anger and dreaming. Another group of tryptamine derivatives, emphasized here, is the one of dimethyltryptamines. Psilocin, psilocybin, bufotenin are hallucinogens. Triptans are synthetic antimigraine drugs, now widely used.