4-HO-MPT, also referred to as meprocin, is a psychedelic substance classified within the tryptamine family of compounds. It serves as a higher homologue of psilocin, a naturally occurring substituted tryptamine, and is specifically the 4-hydroxyl analog of MPT.

CAS Number763035-03-6 (Free base) 77872-42-5 (Hydrochloride) 
3D model (JSmol)Interactive image
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The initial synthesis and evaluation of 4-HO-MPT were conducted by biochemist Alexander Shulgin, with his findings documented in his 1994 book titled “TiHKAL.”

Dosage and duration

For psychedelic effects, the dosage and duration are listed as “unknown” in TiHKAL.


Limited information regarding the pharmacological characteristics, metabolic processes, and potential toxicity associated with 4-HO-MPT is available. In a solitary trial involving the oral consumption of 8 mg of 4-HO-MPT HCl, as documented in TiHKAL, reported effects included visual distortions, sensations of vertigo, and mild insomnia.

Legal status

4-HO-MPT is not listed as a scheduled substance under the United Nations’ Convention on Psychotropic Substances.

United States At the federal level in the United States, 4-HO-MPT is not classified as a controlled substance. However, it’s important to note that it might fall under the category of psilocin analogs, which could potentially lead to legal repercussions for sales or possession with the intent of human consumption under the Federal Analogue Act.


1. What is 4-HO-MPT?

  • 4-HO-MPT, short for 4-Hydroxy-N-methyl-N-propyltryptamine or meprocin, is a psychedelic substance belonging to the tryptamine class of compounds.

2. How does 4-HO-MPT work?

  • 4-HO-MPT primarily affects the serotonin receptors in the brain, leading to altered perception, mood changes, and other psychedelic experiences.

3. Is 4-HO-MPT regulated internationally?

  • No, 4-HO-MPT is not scheduled by the United Nations Convention on Psychotropic Substances.

4. What is the legal status of 4-HO-MPT in the United States?

  • At the federal level, 4-HO-MPT is not classified as a controlled substance. However, it could potentially be treated as an analog of psilocin under the Federal Analogue Act, leading to legal consequences.

5. What effects are associated with 4-HO-MPT use?

  • Reported effects of 4-HO-MPT use may include visual distortions, sensations of vertigo, and mild insomnia. However, experiences can vary among individuals.

6. Are there any known safety precautions for using 4-HO-MPT?

  • As with all psychedelic substances, caution is essential. Start with a low dose in a safe and controlled environment. Consider having a sober and experienced sitter present. Be aware of potential interactions with other substances and any personal medical conditions.

7. How can one ensure the purity of 4-HO-MPT?

  • To ensure the substance’s purity, obtaining it from reputable sources is advisable. Additionally, you can have samples tested by analytical methods if you doubt their authenticity.

8. Is there any ongoing research on the potential medical uses of 4-HO-MPT?

  • Currently, 4-HO-MPT is primarily considered a research chemical, and its medical applications are not established. However, research in this area may continue in the future.

9. How does 4-HO-MPT compare to other psychedelics like psilocybin or LSD?

  • 4-HO-MPT is chemically related to other psychedelics like psilocybin but can have distinct effects and experiences associated with its use. Each substance has unique properties.

10. Where can I find more information about 4-HO-MPT?

  • You can find more information about 4-HO-MPT in scientific literature, research papers, and online resources dedicated to psychedelics. Ensure that the information you access is from reputable sources.


  1. 4-HO-MPT Entry on TIHKAL at Erowid.org provides detailed information about this psychedelic substance and its effects.
  2. “Convention on Psychotropic Substances, 1971.” This international agreement is aimed at regulating controlled substances. Archived from the original on January 19, 2022. Retrieved on June 10, 2016.
  3. “§1308.11 Schedule I.” This refers to the specific section of U.S. drug laws related to Schedule I controlled substances. Archived from the original on August 27, 2009. Retrieved on June 10, 2016.
  4. Erowid Analog Law Vault: Federal Controlled Substance Analogue Act Summary contains information about the U.S. federal law that pertains to analogs of controlled substances.

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