α-Methyl-5-hydroxytryptamine is a tryptamine derivative closely related to the neurotransmitter serotonin. It acts as a moderately selective full agonist at the 5-HT₂ receptors, having the highest affinity for 5-HT_2B and the lowest for 5-HT_2A.

5-hydroxytryptamine(5-HT) is an important neurotransmitter made by neurons in the central nervous system. These functions are mediated by a large number of receptors.After it is released by a neuron, 5-HT activates receptors located on nearby neurons.Several plants contain serotonin together with a family of related tryptamines that are methylated at the amino (NH₂) and (OH) groups, are N-oxides, or miss the OH group. These compounds do reach the brain, although some portion of them are metabolized by MAO-B enzymes in the liver. Examples are plants from the Anadenanthera genus that are used in the hallucinogenic yopo snuff.