Sleep aids: The options

Sleep aids available without a prescription are widely available. Common choices and the potential side effects include:

• Diphenhydramine (Benadryl). Diphenhydramine is an antihistamine that can make you sleepy. Side effects might include daytime drowsiness, dry mouth, constipation and urinary retention.
• Doxylamine (Unisom). Doxylamine is also a sedating antihistamine. Side effects are similar to those of diphenhydramine and may include daytime drowsiness, dry mouth, constipation and urinary retention.
• Melatonin. The hormone melatonin helps control your natural sleep-wake cycle. Some research suggests that melatonin supplements might be helpful in treating jet lag or reducing the time it takes to fall asleep — although the effect is typically mild. Side effects can include headaches, nausea and daytime sleepiness.
• Valerian. Supplements made from this plant are sometimes taken as sleep aids. Although a few studies show some therapeutic benefit, other studies haven't found the same benefits. Side effects appear to be mild and may include headache and weakness.

Generic versions with the same active ingredients as brand-name sleep aids are commonly available. Generics have the same risks and benefits as their brand-name counterparts. They are often available at a more reasonable cost.