What is melatonin?
Melatonin is a manmade form of a hormone produced in the brain that helps regulate your sleep and wake cycle.
Melatonin has been used in alternative medicine as a likely effective aid in treating insomnia (trouble falling asleep or staying asleep). It is also likely effective in treating sleep disorders in people who are blind.
Melatonin is also possibly effective in treating jet lag, high blood pressure, tumors, low blood platelets (blood cells that help your blood to clot), insomnia caused by withdrawal from drug addiction, or anxiety caused by surgery. A topical form of melatonin applied to the skin is possibly effective in preventing sunburn.
Melatonin has also been used to treat infertility, to improve sleep problems caused by shift work, or to enhance athletic performance. However, research has shown that it may not be effective in treating these conditions.
Other uses not proven with research have included treating depression, bipolar disorder, dementia, macular degeneration, attention deficit hyperactivity disorder, enlarged prostate, chronic fatigue syndrome, fibromyalgia, restless leg syndrome, stomach ulcers, irritable bowel syndrome, nicotine withdrawal, and many other conditions.
It is not certain whether melatonin is effective in treating any medical condition. Medicinal use of this product has not been approved by the FDA.
Melatonin is often sold as an herbal supplement. There are no regulated manufacturing standards in place for many herbal compounds and some marketed supplements have been found to be contaminated with toxic metals or other drugs. Herbal/health supplements should be purchased from a reliable source to minimize the risk of contamination.
Not all uses for melatonin have been approved by the FDA. Melatonin should not be used in place of medication prescribed for you by your doctor.
Melatonin is often sold as a dietary supplement. There are no regulated manufacturing standards in place for many herbal compounds and some marketed supplements have been found to be contaminated with toxic metals or other drugs. Herbal/health supplements should be purchased from a reliable source to minimize the risk of contamination.
The use of melatonin derived from animal pineal tissue may carry the risk of contamination or the means of transmitting viral material. The synthetic form of this medication does not carry this risk.
Follow all directions on the product label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.
Before taking this medicine
You should not use melatonin if you are allergic to it.
Before using melatonin, talk to your healthcare provider. You may not be able to use this medicine if you have certain medical conditions, especially:
- a bleeding or blood clotting disorder such as hemophilia;
- high or low blood pressure;
- epilepsy or other seizure disorder; or
- if you are using any medicine to prevent organ transplant rejection.
It is not known whether melatonin will harm an unborn baby. Do not use this product without medical advice if you are pregnant.
High doses of this medicine may affect ovulation, making it difficult for you to get pregnant.
It is not known whether melatonin passes into breast milk or if it could harm a nursing baby. Do not use this product without medical advice if you are breast-feeding a baby.
Do not give any herbal/health supplement to a child without medical advice.
How should I take melatonin?
If you choose to use melatonin, use it as directed on the package or as directed by your doctor, pharmacist, or other healthcare provider. Do not use more of this product than is recommended on the label.
When considering the use of herbal supplements, seek the advice of your doctor. You may also consider consulting a practitioner who is trained in the use of herbal/health supplements.
Use the lowest dose of melatonin when you first start taking this product.
Take melatonin at bedtime, or when you are getting ready for sleep. If you use this product to treat jet lag, take the dose at bedtime on the day you arrive at your destination and keep using this product for 2 to 5 days.
If you take this product to treat other conditions not related to sleep, follow your healthcare provider’s instructions about when and how to take melatonin.
To take the orally disintegrating tablet:
- Keep the tablet in its blister pack until you are ready to take it. Open the package and peel back the foil. Do not push a tablet through the foil or you may damage the tablet.
- Use dry hands to remove the tablet and place it in your mouth.
- Do not swallow the tablet whole. Allow it to dissolve in your mouth without chewing. If desired, you may drink liquid to help swallow the dissolved tablet.
Call your doctor if the condition you are treating with melatonin does not improve, or if it gets worse while using this product.
Store at room temperature away from moisture and heat.
What happens if I miss a dose?
Since melatonin is used when needed, you may not be on a dosing schedule. If you are on a schedule, use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
What should I avoid while taking melatonin?
Melatonin may impair your thinking or reactions. Avoid driving or operating machinery for a least 4 hours after taking this medicine. This product may also affect your sleep-wake cycle for several days if you are traveling through many different time zones.
Avoid using melatonin with other herbal/health supplements. It can increase your risk of bleeding, seizures, or low blood pressure. Using certain products together can increase these risks.
Avoid coffee, tea, cola, energy drinks, or other products that contain caffeine.
Melatonin side effects
Get emergency medical help if you have any of these signs of an allergic reaction to melatonin: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Although not all side effects are known, melatonin is thought to be possibly safe when taken for a short period of time (up to 2 years in some people).
Common melatonin side effects may include:
- daytime drowsiness;
- depressed mood, feeling irritable;
- stomach pain;
- headache; or
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
See also: Side effects (in more detail)
What other drugs will affect melatonin?
Taking this product with other drugs that make you sleepy can worsen this effect. Ask your doctor before taking melatonin with a sleeping pill, antidepressant, sedative, narcotic pain medicine, muscle relaxer, seizure medicine, or herbal/health supplements may also cause drowsiness (tryptophan, California poppy, chamomile, gotu kola, kava, St. John’s wort, skullcap, valerian, and others).
Do not take this medicine without medical advice if you are using any of the following medications:
- an antibiotic;
- aspirin or acetaminophen (Tylenol);
- birth control pills;
- insulin or oral diabetes medicine;
- narcotic pain medicine;
- stomach medicine – lansoprazole (Prevacid), omeprazole (Prilosec), ondansetron (Zofran);
- ADHD medication – methylphenidate, Adderall, Ritalin, and others;
- heart or blood pressure medicine – mexiletine, propranolol, verapamil;
- medicine to treat or prevent blood clots – clopidogrel (Plavix), warfarin (Coumadin, Jantoven);
- NSAIDs (nonsteroidal anti-inflammatory drugs) – ibuprofen (Advil, Motrin), naproxen (Aleve), celecoxib, diclofenac, indomethacin, meloxicam, and others; or
- steroid medicine – prednisone, and others.
This list is not complete. Other drugs may interact with melatonin, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this product guide.