5-Methyltryptamine

5-Methyltryptamine (5-MeT, 5-Me-T) is a non-selective serotonin receptor agonist and serotonin releasing agent of the tryptamine family that has been used in scientific research. It is related to other 5-substituted tryptamines such as serotonin (5-hydroxytryptamine; 5-HT) and 5-methoxytryptamine (5-MeO-T). The compound is also a positional isomer of N-methyltryptamine (NMT).

Pharmacology

5-MeT is known to act as a potent serotonin 5-HT_2A receptor full agonist, with an EC₅₀Tooltip half-maximal effective concentration of 6.00 nM and an E_maxTooltip maximal efficacy of 100%. In addition, it is known to be a ligand of the serotonin 5-HT_1A and 5-HT_2B receptors and an agonist of the serotonin 5-HT_1D and 5-HT_2C receptors. Similarly to tryptamine and 5-MeO-T, but in contrast to serotonin, 5-MeT shows very low potency as an agonist of the serotonin 5-HT₃ receptor (EC₅₀ = 60,000 nM).

In addition to acting as an agonist of various serotonin receptors, 5-MeT is a monoamine releasing agent (MRA), with high selectivity for induction of serotonin release over induction of dopamine and norepinephrine release (EC₅₀ = 139 nM, >10,000 nM, and >10,000 nM, respectively, in rat brain synaptosomes). However, its potency for induction of serotonin release in this system is 23-fold lower than its potency as a serotonin 5-HT_2A receptor agonist.

Tryptamines without substitutions at the amine or alpha carbon, such as tryptamine, serotonin, and 5-MeO-T, are known to be very rapidly metabolized and thereby inactivated by monoamine oxidase A (MAO-A) in vivo and to have very short elimination half-lives. However, given intravenously at sufficiently high doses, tryptamine is still known to be able to produce weak and short-lived serotonergic psychedelic effects in humans.