Making Sense of Medicine

So here’s what I’ve discovered: Melatonin is a hormone. I’ve known that since medical school, of course, but that fact has struck me as peculiar these past few weeks. Why? Because it’s sold over the counter, and many people take massive amounts of it. No other hormone is available like this. The use of other hormones, such as insulin and thyroid hormone, need careful monitoring. Is melatonin so universally safe that it can be taken at any dose, for however long? The more we learn about melatonin, the less that seems to be the case.

Hormones are substances produced in one place that then go into the bloodstream and have their effect somewhere else. Melatonin is produced in the pineal body, which is just outside the brain proper. Ten times as much of it is made during the night as during the day. Our bodies sense when it is dark and tell the pineal body to make melatonin. If we cross six time zones, however, it takes a few days for the pineal to catch up and produce melatonin at the proper time. Hence comes Jet Lag.

So do people with insomnia benefit from melatonin? Many of them swear by it, but I’m wondering whether they are taking too much. The pills in pharmacies are generally 3mg or 5mg. But the amount that reproduces what our bodies produce at night is equivalent to somewhere between 0.1mg and 0.5mg. Higher doses flood the brain with melatonin, and make it actually less sensitive to its effects. So here is where it is not good to follow the “If a little is good, then more is better” principle. Since a little is all that is needed, stick with a little.

Studies are showing that the ideal amount of melatonin for sleep problems seems to be 0.3mg. But how can you take “0.3mg” when the pill is 3mg? Do you crumble it up and take a tenth, somehow? Not practical. There are liquid preparations available, with one dropperful giving 1.0mg. So you could take a third of a dropperful. If you can’t find it at your pharmacy, check online at www.drugstore.com.

As we age, we gradually produce less melatonin. I wonder if this is why so many older people have trouble sleeping. In the last few weeks, since I’ve been reading about melatonin, I’ve started recommending it to my older patients with insomnia. But I urge them to use the liquid so they only take 0.3mg a night. They may end up needing a little more, but, as with all medications, I much prefer starting at a low dose and creeping up slowly. I’ll follow up in a few months with how people have responded.