Melatonin - The Sleep Hormone

Dr. Sarah Myhill

www.drmyhill.co.uk

Melatonin is the natural hormone which controls our biological clock, telling us when it is time to sleep and time to wake up. Sleep is an essential for life just like food and water. Some people are larks (I am in bed at 9.30, up at 5.30) some are owls (bed at 12.00, up at 8.00). It is melatonin which makes it that way.

Melatonin is also a powerful antioxidant and has been heralded as an anti-ageing drug (sleep is the best cosmetic!). It is made in the pineal gland in the brain.

There is also an interesting relationship between brain neurotransmitters and melatonin. The raw material is an amino acid tryptophan which is converted in the body to 5 hydroxytryptophan from which serotonin (the 'happy' neurotransmitter which Prozac works on) and then melatonin.

Tryptophan -> 5 hydroxy tryptophan -> serotonin -> melatonin

Melatonin levels are normally very low in the day

Melatonin has been of proven benefit in jet lag (5mgs at night), for cancer therapy (40-50mgs at night), for chronic insomnia (75mgs at night) and in elderly insomniacs (1-2mgs at night). I usually suggest 3mgs at night.

Using these low doses of melatonin I do not measure levels first. However if a patient wanted to try high dose, then I would insist on monitoring levels.

The only side effect which has been a problem for some patients is depression and so I warn patients to look out for that. Other side effects are mentioned in the literature but these must just apply to the high doses because I have not seen them. They include confusion, headache, hypothermia, itching and tachycardia.

Availability: melatonin is available over the counter in America, but not in UK where at present it is a prescription only drug.