Mixing Diphenhydramine (Benadryl) and Mephedrone (meow)
Dangerous
At recreational doses this risks serotonin syndrome and heart trouble, and if one wears off first the other can overwhelm you. Do not combine.
There is a high risk of serotonin syndrome at recreational dosages. Both can dull each other's effects, so if one wears off before the other it's possible to overdose due to the lack of counteraction. Medical dosages are reported not to be a concern for the general population. Both substances affect the heart and may lead to further dangerous heart complications at higher dosages. The combination may increase each other's side effects, such as dizziness and drowsiness. At higher dosages, the combination may increase each other's side effects, such as delirium, mania, and psychosis.
This combination carries bodily risk and can go badly psychologically. The headspace part often arrives first and makes the physical part harder to notice.
Headspace vs physical riskWhat to do
- Say what was taken and how much.Responders need it, and in most US states Good Samaritan laws protect both of you from drug possession charges when you call for an overdose.
- Unresponsive: put them on their side, tilt the head back, and stay until help arrives.Never leave someone alone to “sleep it off”.
- Never Use Alone 1-800-484-3731Stays on the line and sends help if you stop responding.
- Full steps: what to do if it is already happeningOverdose signs, the recovery position, what to say on the call, and whether you can be charged for making it.
- Poison Control 1-800-222-1222Free and 24/7, for “is this bad?” before it becomes an emergency.
Can you mix Diphenhydramine (Benadryl) and Mephedrone (meow)?
MixSafe rates mixing Diphenhydramine and Mephedrone as "Dangerous" — high risk of death or life-changing injury. Do not combine. Source: TripSit drug combination chart, retrieved 2026-08-20. Educational information, not medical advice.
- Diphenhydramine also called
- benadryl, dph, sleep aid, zzzquil, unisom, doxylamine
- Mephedrone also called
- 4-mmc, 4mmc, meow, m-cat, 4-methylmethcathinone, bath salts
TripSit drug combination chart, retrieved 2026-08-20. View the dataset.
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All combinations →Rated dangerous. Educational information only, not medical advice. Absence of a documented interaction is not evidence of safety.