4-Methylphenmetrazine, also known as mephenmetrazine, 4-MPM, or PAL-747, is a recreational designer substance celebrated for its stimulating effects. This compound is a derivative of phenylmorpholine, sharing a close structural relation with more widely recognized substances like phenmetrazine and 3-fluorophenmetrazine. It initially came to attention in Slovenia in 2015, and subsequent research has revealed its capacity as a monoamine releaser, with a notable inclination toward releasing serotonin.

IUPAC name
CAS Number1094649-71-4
1998216-41-3 (Hydrochloride)
PubChem CID43169333
Chemical and physical data
Molar mass191.274 g·mol−1


1. What is 4-Methylphenmetrazine (4-MPM)?

4-Methylphenmetrazine, often called 4-MPM, is a synthetic designer drug known for its stimulating effects. It is structurally related to phenmetrazine and 3-fluorophenmetrazine, both of which have a history of use as stimulants.

2. How is 4-MPM different from other stimulants?

4-Methylphenmetrazine is distinguished by its chemical structure, differentiating it from other stimulants. Its structural similarity to phenmetrazine suggests similar effects, although there may be variations in potency and specific actions.

3. What are the effects of 4-MPM?

As a stimulant, 4-methyl phenmetrazine can produce effects such as increased alertness, enhanced energy, and improved focus. Users have reported experiencing heightened motivation and sociability. It may also lead to appetite suppression.

4. Is 4-MPM legal?

The legal status of 4-methylphenmetrazine varies by country and jurisdiction. It’s important to note that laws can change over time, so always check your local regulations and stay informed about the legality of this substance in your area.

5. How is 4-MPM typically consumed?

4-MPM is often taken orally in its powder form. Some users may measure and consume it in specific doses, but handling any research chemicals carefully and following harm-reduction practices is essential.

6. What precautions should be taken when using 4-MPM?

You must know the potential risks of using 4-methyl phenmetrazine or any research chemical. Start with a low dose, and never combine it with other substances, especially alcohol or drugs. Always prioritize your health and safety.

7. Are there any known risks or side effects?

Stimulant substances like 4-MPM can have side effects, including increased heart rate, blood pressure, and potential anxiety. Prolonged or high-dose use may lead to adverse health effects. It’s essential to use such substances responsibly and in moderation.

8. Can 4-MPM be used for medical purposes?

4-Methylphenmetrazine is not approved for medical use, and its safety and efficacy for therapeutic purposes have not been established. It is primarily used recreationally or as a research chemical.

9. Is 4-MPM addictive?

The potential for addiction to 4-methyl phenmetrazine is a concern, as it shares characteristics with other stimulants that can lead to dependence. Frequent use or misuse can increase this risk.

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

For more information about 4-methyl phenmetrazine, its effects, legal status, and potential risks, consider referring to reputable sources, scientific literature, and harm reduction organizations. Always prioritize your well-being and make informed choices.


  1. “Chemical Analysis Report: 4-MPH (C12H17NO) – 3-methyl-2(p-tolyl)morpholine” (PDF). Issued by the National Forensic Laboratory in Slovenia. Dated 14th October 2015.
  2. “Annual Report on the Implementation of Council Decision 2005/387/JHA by Europol in 2015” (PDF). Compiled by The European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) and Europol.
  3. United States Patent US 20130203752. Inventors: Blough BE, Rothman R, Landavazo A, Page KM, Decker AM. Title: “Phenylmorpholines and Analogues Thereof.” Published on 8th August 2013, and issued on 11th April 2017. Assigned to the National Institutes of Health, U.S. Department of Health and Human Services.
  4. McLaughlin G, Baumann MH, Kavanagh PV, Morris N, Power JD, Dowling G, et al. (September 2018). “Synthesis, Analytical Characterization, and Monoamine Transporter Activity of the New Psychoactive Substance 4-methylphenmetrazine (4-MPM), with Differentiation from its Ortho- and Meta-Positional Isomers.” Published in Drug Testing and Analysis, Volume 10, Issue 9, Pages 1404–1416. DOI: 10.1002/dta.2396. PMC 7316143. PMID 29673128.

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