4-Hydroxy-α-methyltryptamine (4-HO-αMT) is a psychedelic drug of the tryptamine class. It is a close structural analogue of α-methyltryptamine (αMT) and produces similar effects to it, but with exacerbated side effects similarly to 5-MeO-αMT. Alexander Shulgin describes 4-HO-αMT briefly in his book TiHKAL:
The 4-hydroxy analogue of αMT has been looked at in human subjects. It is reported to be markedly visual in its effects, with some subjects reporting dizziness and a depressed feeling. There were, however, several toxic signs at doses of 15 to 20 milligrams orally, including abdominal pain, tachycardia, increased blood pressure and, with several people, headache and diarrhea.