April 19th, 2011
05:03 PM ET
Lisa Shives, M.D., is the founder of Northshore Sleep Medicine in Evanston, Illinois. She blogs on Tuesdays on The Chart. Read more from her at Dr. Lisa Shives’ Sleep Better Blog.
“The frustrating thing is I watch my husband take his melatonin and ‘poof’ it’s like the sandman flew in through the window and sprinkled sand in his eyes. He is out. Me? Nothing. I lie there for hours even if I take two or three pills.”
I hear this lot. Melatonin works remarkably well for some people and has no affect on others.
Melatonin is a naturally occurring neuro-hormone that is secreted by the pineal gland in the brain. When released from the pineal gland, melatonin causes drowsiness and a decrease in core body temperature. The levels of melatonin rise throughout the evening hours and peak in the middle of the night. That is if there is relative darkness. Even ordinary room light (approximately 100 lux) can cause a rapid suppression in melatonin. This is why sleep doctors are always telling people, at least people who have trouble falling asleep, that they should avoid reading in bed.
Research suggests that melatonin not only helps us sleep and maintain our 24-hour clock, but that it acts as a powerful antioxidant that destroys cancerous cells. It may also boost immunity and help in weight loss. The antioxidant properties are thought to explain why night shift workers have a higher rate of cancer. Night after night they suppress their melatonin by staying up and being exposed to light.
Melatonin has been studied as a sleep promoting agent in doses ranging from 0.3 mg to 80 mg and the results are always disappointing. There are a few hypotheses why that is the case.
First, melatonin is sold as a dietary supplement in this country and you can’t rely on the dose really being what the bottle says it is.
I have been trying to find out if there is brand of melatonin sold in the U.S. that is manufactured in Western Europe. Many European countries such as Germany regulate their herbal supplements as strictly as they do their pharmaceuticals. In fact, Germany considers melatonin a prescription medication.
Second, the timing of the dosing of melatonin when treating insomnia has not been firmly established.
For example, when we are using it to shift people’s circadian rhythm, we typically give it approximately six hours before desired bedtime. This can slowly phase advance them, i.e. get them to fall asleep earlier.
I experiment with the timing with patients. I start at 30 minutes before bedtime, in order to use it as a hypnotic, but if we don’t achieve the desired sleepiness, then I advise taking it 60 minutes before bed, then 90 minutes and so forth until we are actually using it as a chronobiotic, i.e. shifting the biological clock.
I always advise caution that they not go out and about or operate heavy machinery while we are first administering the melatonin.
Third, melatonin might work better on some people because they have a naturally low level whereas it has little effect on people who have normal levels. This hypothesis is extrapolated from literature that shows that melatonin is more effective when administered in the daytime when our natural levels are low. Also, melatonin seems to be more effective in elderly patients who often have low melatonin. Further supporting evidence might be the fact that most research shows little difference in response whether you give low dose or high dose.
Finally, perhaps oral administration is not the best method of delivery the drug. It is manufactured as sublingual (under the tongue) and as transdermal (skin) patches, but whether these routes of delivery are more effective remains to be tested.
We should also keep in mind that certain medications such as beta blockers and anti-depressants can suppress melatonin levels.
Although the effectiveness of melatonin is questionable, it is generally considered safe in adults. Common side effects include morning grogginess, headache, vivid dreaming.
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