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Doctor doctor: Will melatonin supplements help me to sleep at night?

Dear Doctor I suffer from insomnia and melatonin has been suggested as a cure. How does it work and is it safe?

Can you tell me about melatonin? I suffer with insomnia and it was recommended to help me sleep.

Melatonin is a hormone secreted by the pineal gland in the brain. It helps maintain the body's 24-hour clock that helps us fall asleep and wake up. When it is dark, your body produces more melatonin and your natural levels of this hormone are highest just before bed-time.

Young children have the highest levels of night-time melatonin and as we get older levels of it drop. This may explain why older adults have sleep problems and tend to go to bed and wake up earlier.

Being exposed to bright lights in the evening or too little light during the day can also disrupt the body's melatonin cycles.

Jet lag, shift work and poor vision increase your risk of lower-than-normal melatonin levels.

How does it work, and can melatonin be used for all types of insomnia?

It's not clear how exactly melatonin works. There is evidence that it helps prevent jet lag, especially those who cross five or more time zones. It also helps in reducing the time it takes to fall asleep, and boosts daytime alertness for people who have insomnia (especially in those over 55). Melatonin supplements may help women with sleep problems associated with the menopause, but it doesn't relieve other symptoms, such as hot flushes or night sweats.

What dose of melatonin should I take?

There is no recommended dose for melatonin supplements. The best approach is to keep the dose close to the amount that your body normally produces -- less than 0.3mg per day.

For insomnia 1-3mg one hour before bedtime is usually effective.

For jet lag take 0.5-5mg of melatonin one hour before bedtime at the final destination. Alternatively take 1-5mg one hour before bedtime for two days before departure and for two to three days on arrival.

What are the risks of taking melatonin?

Melatonin can cause drowsiness if taken during the day. If you find you are drowsy the morning after, try a lower dose.

Some people may have vivid dreams or nightmares.

Other possible side effects include dizziness, headaches, confusion and abdominal pain. The long-term effects of melatonin are not known and it should not be taken for more than six to eight weeks.

Melatonin may interact with medications, including: blood-thinning medication, diabetes medication, immunosuppressants and steroids, and blood-pressure medication such as beta-blockers/ calcium-channel blockers NSAIDS.

Caffeine, alcohol and smoking lower levels of melatonin.

Make sure supplements are made of artificial ingredients as melatonin extracted from animals may contain viruses.