Doxylamine is a member of the ethanolamine class of antihistamines and has anti-allergy power superior to almost every other antihistamine on the market, with the exception of diphenhydramine (Benadryl).[2] It is also the most effective over-the-counter sedative available in the United States,[2] and is more sedating than some prescription hypnotics. One study found that doxylamine succinate is possibly more effective than the barbiturate phenobarbital for use as a sedative.[2] For this reason, doxylamine has sometimes been used off label in a manner similar to diphenhydramine for the reduction of anxiety symptoms.[citation needed]

The dosage required to induce hypnosis (sleep) can be as low as 6.25 mg, but is usually effective in dosages of up to 25 mg. Higher doses are not recommended by the United States Food and Drug Administration, although single dosage recommendations of up to 50 mg are common in some countries, including Australia, where it is marketed under the names Restavit and Dozile.