Tryptamine is a monoamine alkaloid found in plants, fungi, and animals. It contains an indole ring structure, and is structurally similar to the amino acid tryptophan, from which it derives its name.

Metitepine (INN), also commonly known as methiothepin, is a drug that acts as an antagonist at various serotonin and dopamine receptors.

Zacopride is a highly potent 5-HT3 receptor antagonist (Kd = 0.38 nM) and 5-HT4 receptor agonist (Ki = 373 nM). It also is a selective IK1 channel agonist.