By Lisa StraussSpecial to The Washington Post Many of us think of melatonin only as an over-the-counter sleep aid, given its widespread use. But melatonin is a hormone already circulating through our bodies, like adrenaline or cortisol. As a sleep psychologist, when I first mention melatonin to patients, they often interrupt to say: “I tried that.
It didn’t work.” They are confusing our bodies’ naturally synthesized, “endogenous” melatonin with pill, gummy, liquid or other “exogenous” forms of melatonin. Both endogenous and exogenous melatonin can help us sleep better if we understand how to sidestep pitfalls and make them work for us.
Melatonin, among other functions, tells our bodies when it is time to sleep. And this function is cued by the timing of light and darkness. Darkness promotes melatonin, and light suppresses it.
The blue end of the spectrum (present even in white light) is melatonin’s most potent — but not exclusive — suppressant. But over the millennia, we have introduced inconsistency to the timing of light and darkness, and therefore to our melatonin and sleep rhythms. Humans evolved near the equator.
Day and night were of roughly equal length, and there was scant seasonal variation in patterns of light and dark. As we migrated to other latitudes, and as we modernized, we introduced seasonal variation, artificial light, cross-time-zone travel, daylight saving time and close-range screens. Luckily, our bodies evolved to adjust to new “t.
