6-Methoxytryptamine (6-MeO-T; developmental code name PAL-263) is a monoamine releasing agent and serotonin receptor modulator of the tryptamine family. It is a positional isomer of 5-methoxytryptamine.

6-Methoxytryptamine is a potent serotonin–norepinephrine–dopamine releasing agent (SNDRA), with EC₅₀Tooltip half-maximal effective concentration values for monoamine release induction of 53.8 nM for serotonin, 113 nM for dopamine, and 465 nM for norepinephrine in rat brain synaptosomes. It is also a full agonist of the serotonin 5-HT_2A receptor, but with very low potency; its EC₅₀ and E_maxTooltip maximal efficacy at this receptor were 2,443 nM and 111%, respectively. In a series of tryptamine derivatives, 6-methoxytryptamine was the least potent serotonin 5-HT_2A receptor agonist, while 5-methoxytryptamine was the most potent serotonin 5-HT_2A receptor agonist, with 5-methoxytryptamine showing approximately 4,857-fold higher potency in terms of serotonin 5-HT_2A receptor agonism than 6-methoxytryptamine. Conversely, whereas 6-methoxytryptamine was a potent monoamine releasing agent, 5-methoxytryptamine showed very low potency in this regard.

6-Methoxytryptamine was first described in the scientific literature by the 1950s.

Certain β-carbolines and harmala alkaloids, such as harmine, harmaline, and tetrahydroharmine, are notable in being naturally occurring cyclized tryptamine derivatives of 6-methoxytryptamine. The same is true of certain iboga alkaloids, such as tabernanthine and ibogaline. Tabernanthalog (DLX-007) is a synthetic simplified ibogalog analogue of tabernanthine that is under development for use as a potential pharmaceutical drug in the treatment of neuropsychiatric disorders.