Melatonin

Common Name(s)

melatonin, pineal hormone, MEL, melatonina

Scientific Name(s)

N-acetyl-5-methoxytryptamine

General Information

Melatonin is a hormone that is found naturally in the body, produced in the pineal gland of the brain. It can also be made synthetically in a laboratory. In our bodies, melatonin helps to regulate the sleep-wake cycle. Darkness causes the body to make more melatonin, while light stops the process.

How is this product usually used?

Melatonin is taken by mouth. It is available in different forms, including regular tablets, sublingual tablets (placed under the tongue), liquids, powders, strips, and capsules. The adult dose of melatonin ranges from 0.1 mg to 10 mg per day taken at or before bedtime.

• Jet lag: 0.5 mg to 10 mg of melatonin per day at bedtime after dark. It should only be used for short-term treatment.
• Sleep-wake cycle, sleep restriction, altered sleep schedule, delayed sleep phase disorder: 0.1 mg to 10 mg once daily at or before bedtime.

Your health care provider may have recommended using this product in other ways. Contact a health care provider if you have questions.

What is this product used for?

Melatonin helps to reset the body's sleep-wake cycle. It is used by people to help:

• increase the total amount of sleep for people suffering from sleep restriction or altered sleep schedule (e.g., shift work, jet lag)
• ease daytime fatigue associated with jet lag
• reduce the time required to fall asleep for people who have delayed sleep phase syndrome
• reset the body's sleep-wake cycle

Most of the research shows that melatonin can help with certain symptoms of jet lag, including alertness, daytime sleepiness, and fatigue. There is some evidence that taking melatonin may not help shorten the time it takes for jet-lagged travellers to fall asleep.

Taking melatonin on a short-term basis can modestly improve the time it takes to fall asleep. More research is needed to confirm this. However, it is not likely to help with sleep adjustment for people who do rotation shift work.

Melatonin has also been studied to help with sleep disturbances in people who are visually impaired, and it has been shown to help improve sleep disorders related to circadian rhythm.

Your health care provider may have recommended this product for other conditions. Contact a health care provider if you have questions.

What else should I be aware of?

Melatonin is safe for most adults when taken by mouth for a short term. If you are using melatonin for more than 4 weeks or your symptoms last more than 4 weeks, consult your health care provider. Common side effects reported include nausea, headache, daytime sleepiness, and dizziness. Do not drive or use machinery for 5 hours after taking melatonin.

It can interact with certain medications, including anticoagulants, birth control pills, diabetes medications, seizure medications, blood pressure medications, sedatives and sleeping pills, psychotropic medications, steroids, and immunosuppressants. It may also increase the levels of certain medications metabolized by various liver enzymes.

Melatonin can cause more drowsiness when used with other medications that may also have this side effect (e.g., alcohol, sedatives, benzodiazepines such as lorazepam, temazepam).

Melatonin should not be used by people who are pregnant or breast-feeding.

Before taking melatonin, consult a health care professional if you have a history of asthma, seizures, diabetes, diseases affecting the immune system, high blood pressure, cardiovascular disease, depression, liver or kidney disease, migraines, hypoglycemia, or hormonal disorders. Due to melatonin’s effects on the immune system, let your health care professional know if you have previously received an organ transplant.

Before taking any new medications, including natural health products, speak to your physician, pharmacist, or other health care provider. Tell your health care provider about any natural health products you may be taking.

Source(s)

1. Health Canada. Licensed Natural Health Products. Melatonin oral. https://webprod.hc-sc.gc.ca/nhpid-bdipsn/atReq.do?atid=melatonin.oral&lang=eng.
2. Health Canada. Licensed Natural Health Products. Melatonin sublingual. https://webprod.hc-sc.gc.ca/nhpid-bdipsn/atReq.do?atid=melatonin.sublinguale&lang=eng.
3. Natural Medicines Comprehensive Database. Melatonin.