Melatonin – The Sleep Hormone
by Dr. Sarah Myhill
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 – 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 a close relationship between melatonin and DHEA. If one is abnormal the other is also likely to be! With stress, such as low blood sugar, DHEA levels run high, so melatonin may be low and this further impairs sleep.
Now, if I see an Adrenocortex Stress Profile (salivary) with high levels of DHEA at night, I prescribe a melatonin supplement.
There is also an interesting relationship between brain neurotransmitters, DHEA 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 (up to 75mgs at night) and in elderly insomniacs (1-2mgs at night). I usually suggest 3mgs at night and to adjust the dose up or down according to the response. Everyone seems different, for some, just 1mg is sufficient. I don’t use more than 9mgs.
Using these low doses of melatonin I do not measure levels first. However if a patient wanted to try a high dose, (above 10mg) 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.