Tyramine is a naturally occurring monoamine compound and trace amine derived from the amino acid tyrosine. Tyramine occurs widely in plants and animals, and is metabolized by the enzyme monoamine oxidase. Tyramine is an alpha-adrenergic agonist. Hypertension can occur, from ingestion of tyramine-rich foods in conjunction with monoamine oxidase inhibitors. The possibility that tyramine acts directly as a neurotransmitter was revealed by the discovery of a G protein-coupled receptor with high affinity for tyramine, called TAAR. It exhibits sympathomimetic effects by causing the release of endogenic norepinephrine. It has been used in mydriatic eyedrops. This has been said to reduce the intraocular pressure in rabbits and in some patients with open-angle glaucoma.

5-(2-Aminopropyl)benzofuran (5-APB) is an empathogenic psychoactive compound of the substituted benzofuran, substituted amphetamine and substituted phenethylamine classes. 5-(2-Aminopropyl)benzofuran is a serotonin–norepinephrine–dopamine reuptake inhibitor and serotonin–norepinephrine–dopamine releasing agent. The toxicity and long-term health effects of recreational 5-APB use do not seem to have been studied in any scientific context and the exact toxic dosage is unknown/ 5-(2-Aminopropyl)benzofuran 's high affinity for the 5-HT2b receptor makes it likely that 5-APB would be cardiotoxic with long-term use, as seen in other 5-HT2B agonists such as fenfluramine and MDMA.