Mixing Alcohol and Diphenhydramine (Benadryl)
Dangerous
At everyday doses, studies find diphenhydramine makes alcohol's hit to coordination and reaction time much worse, and you will not feel how impaired you are: do not drive. Larger amounts can knock you out. Do not combine; put anyone who passes out on their side.
The two substances potentiate each other strongly and unpredictably, and may rapidly lead to unconsciousness. They both increase each other's side effects such as ataxia, sedation, and CNS depression. Blackouts and memory loss are significantly increased. If the user falls unconscious while under the influence there is a severe risk of vomit aspiration if they are not placed in the recovery position. Alcohol may also increase the deliriant effects of diphenhydramine. It should also be noted if the individual consuming alcohol typically has a flushing response to alcohol, diphenhydramine may reduce the reaction and mask some of the effects of the alcohol.
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 Alcohol and Diphenhydramine (Benadryl)?
MixSafe rates mixing Alcohol and Diphenhydramine 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.
- Alcohol also called
- alc, booze, beer, wine, liquor, ethanol
- Diphenhydramine also called
- benadryl, dph, sleep aid, zzzquil, unisom, doxylamine
TripSit drug combination chart, retrieved 2026-08-20. View the dataset.
The summary above also draws on:
- Moser L et al. Effects of terfenadine and diphenhydramine alone or in combination with diazepam or alcohol on psychomotor performance. Eur J Clin Pharmacol. 1978. https://pubmed.ncbi.nlm.nih.gov/33053/
- Weiler JM et al. Effects of fexofenadine, diphenhydramine, and alcohol on driving performance. Ann Intern Med. 2000. https://pubmed.ncbi.nlm.nih.gov/10691585/
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Rated dangerous. Educational information only, not medical advice. Absence of a documented interaction is not evidence of safety.