Over-the-Counter Drugs
(Benadryl, Nytol, Sominex, Unisom, Bayer PM, Excedrin PM)

What are they? All of these products have an antihistamine (the drug that helps fight allergies and often makes you groggy) as their sleep-inducing ingredient.

How long can you take them? Ten to 14 days.

Do they work? Yes—sort of. They generally lose effectiveness after two or three days. In addition, many people don't get "good sleep" with antihistamines, possibly because the period of time spent in REM sleep, considered essential for memory and learning, can be altered. Side effects may include next-day grogginess, dizziness, dry mouth, headache, and trouble with coordination. Doctors don't usually recommend their use as sleep aids.

Benzodiazepine Hypnotics
(Restoril, Dalmane, ProSom, Halcion)

What are they? These prescription drugs are the sedatives that have traditionally been used to treat insomnia, and are still often given to patients in hospitals.

How long can you take them? Generally, seven to ten days.

Do they work? Yes, especially for patients who have trouble staying asleep all night. But because they alter REM patterns (as well as non-REM phases), they can lead to poorer quality sleep and next-day "hangovers," with grogginess, slurred speech, and coordination problems. Halcion has been linked to depression, amnesia, hallucinations, and anxiety, although reviews by both the FDA and the Institute of Medicine, an independent group that advises the government, have concluded that the drug is safe when taken in the approved dosages. For all the benzodiazepines, there are risks, especially when taken in higher doses or for longer than prescribed; in particular, these drugs can be addictive.

Nonbenzodiazepine Hypnotics
(Ambien, Sonata)

What are they? Available by prescription only, Ambien and Sonata represent the newest class of sleep medications.

How long can you take them? Generally, seven to ten days.

Do they work? Yes. Ambien and Sonata act on the same parts of the brain as benzodiazepines, but for shorter periods of time and with fewer side effects. They bring sleep patterns closer to normal, says Max Hirshkowitz, PhD, director of the Sleep Disorders and Research Center at the VA Medical Center in Houston, and have eliminated most problems with hangover effects. Sonata typically lasts about three hours and is prescribed to help people who have trouble falling asleep; it can also be taken in the middle of the night with little risk of next-day grogginess. Ambien lasts longer and is taken before bed. These drugs are still recommended only for short-term use, a problem that may be solved by new drugs in the pipeline, including Estorra, which is likely to be approved for longer-term use.

(Elavil, Endep, Enovil)

What are they? Tricyclic antidepressants are an older class of prescription drugs used primarily to treat depression.

How long can you take them? No limit.

Do they work? It's questionable. Because other drugs are indicated for short-term use only, doctors sometimes resort to tricyclics, which have sedative side effects, for chronic insomnia. "These are inappropriate drugs to use unless you're treating depression as well," Hirshkowitz says. "There is no data on how effective they are for long-term treatment of insomnia; in addition, they can cause other side effects ranging from dry mouth to heart arrhythmias. And it is possible to overdose on tricyclics."


What is it?
Melatonin, a natural hormone produced by a small gland in the brain, regulates the body's sleep-wake cycle. Sold in supplement form, it's available in health food stores and drugstores.

How long can you take it?There have been no conclusive studies on its long-term effects. Doctors recommend using it for the shortest time possible to treat problems like jet lag.

Does it work? Studies have produced conflicting results, but it seems to be most effective for people whose sleep cycles have been thrown off by travel or shift work. Hirshkowitz, whose own informal studies have shown that the amount of melatonin in a pill often bears little resemblance to the dose listed on the label, warns against taking organic melatonin, which is derived from the brains of cattle, since there is an unknown risk of mad cow disease. Stephen H. Sheldon, director of the Sleep Medicine Center at Children's Memorial Hospital in Chicago, recommends taking only synthetic pharmaceutical-grade melatonin (ask a pharmacist for a reliable brand).

Herbal Remedies
(valerian, chamomile, lemon balm, lavender, hops, passionflower, kava)

What are they? Derived from plants, these supplements contain mixtures of dozens of natural compounds that are reputed to aid sleep.

How long can you take them? There are no recommended limits, but research is lacking on long-term effects.

Do they work? No one knows for sure. Like melatonin, herbal remedies are unregulated by the FDA, and what studies have been done show wildly varying results. Also, there's no guarantee about how much of the active ingredient is contained in a preparation. The FDA has, however, issued an advisory saying kava may pose the risk of severe liver problems, including hepatitis, cirrhosis, and liver failure. There have also been reports of patients requiring liver transplants.