Diphenhydramine comes in different forms. The most common are various over-the-counter antihistamines, cold remedies and sleeping aids (including Benadryl, Sominex, Sleep-Eze D and several generic brands). Brands may contain different quantities of diphenhydramine, generally in the 25-50 mg per dose-unit (pill, capsule) range, as well as a variety of other potentially dangerous drugs. It is easy to mis-calculate dosages, so be careful and check to ensure that the product does not contain other dangerous active ingredients.

Diphenhydramine causes drowsiness, lethargy, and sleep even at doses recommended for anti-histamine use. The dosages below are reflective of recreational use where users take doses 4-20 times the recommended dose, stay awake, and try to enjoy the "drunken", delusional state.

Note: Some internet sources equate Diphenhydramine (Benadryl) and Dimenhydrinate (Dramamine). They are actually different chemicals, with different effects and dosage ranges.

The chart below shows approximate recreational dosages for pure diphenhydramine, measured in milligrams (mg).

Warnings

Acetaminophen Warning: Diphenhydramine products containing acetaminophen/paracetamol should not be used recreationally. High doses of acetaminophen can be fatal.

Diphenhydramine products containing other medicines can be harmful if taken in doses above the recommended limits. Dangerous interactions can occur.

1. As with any powerful psychoactive substance, high doses are more likely to induce difficult experiences, negative side effects, allergic responses, etc.