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 a sedating antihistamine. 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.
• 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 indicate some therapeutic benefit, other studies haven't found the same benefits. Side effects appear to be mild and may include headache and weakness.

Store brands containing the same active ingredients as brand-name sleep aids are commonly available, too. Store brands have the same risks and benefits as their brand-name counterparts, often at a more reasonable cost.