MGM-15: dosage

There is no reliable human dosing data for MGM-15. No established dose, no threshold, no duration, no onset time exists in any published source.

MGM-15 is a semi-synthetic opioid derived from kratom alkaloids, chemically a synthetic derivative of 7-hydroxy mitragynine, structurally close to known kratom alkaloids [1][2]. It's reported to be a partial agonist of the mu-opioid receptor [2]. It has been found in tablets and biological samples [1], meaning it exists in the actual drug supply, not just in a lab.

If you're using this anyway:

• Assume the material is inconsistent. Potency between batches is unknown and unknowable. A tablet or bag that "worked fine" last time tells you nothing reliable about the next one.
• Volumetric dosing (dissolving a known total amount in a known volume of liquid and measuring small amounts of that solution) gives you finer control than trying to divide powder by eye or by pill-splitting.
• Start far lower than feels reasonable. With no human reference point, "start low" means lower than you'd start with a drug that has one.
• Never use alone, and never combine with other depressants. Opioids are commonly co-ingested with alcohol or other CNS depressants like benzodiazepines and pregabalin, and this combination increases respiratory depression risk and can produce mixed toxicity that doesn't look like a typical opioid overdose [3].

Have naloxone present and know how to use it before you need it.

References

1. From Kratom to Semi-Synthetic Opioids: The Rise and Risks of MGM-15 — Gour et al., Drug Testing and Analysis 2025;17(12):2384-2389 (via PubMed)
2. Dihydro-7-Hydroxy Mitragynine — NPS Discovery New Drug Monograph (Nov 2025) — Center for Forensic Science Research and Education (CFSRE), NPS Discovery
3. Best Practice Guideline: Acute Opioid Toxicity — Royal College of Emergency Medicine (RCEM)