Melatonin is one of the more popular and available over-the-counter (OTC) drugs for people to take as a sleep aid. In addition to its use for sleep issues, it is reported to affect maladies as diverse as delirium, fertility, migraine headaches, and cancer among several others.

Like most sleep aids, I think it’s important to know exactly what it is before we go ingesting it.

The Basics of Melatonin

Melatonin is chemically known as N-acetyl-5-methoxytryptamine, and it occurs naturally in most plant, animals (including us) and microbes. In humans, it’s a product of the pineal gland in the brain, where it is manufactured from the chemical tryptophan (the same stuff you find in your turkey dinner).

In mammals, melatonin production is triggered by darkness, and stopped by light. This is why it’s known as the darkness hormone, and why it’s essential for our circadian (day/night) rhythms.

When researchers examined the actual blood plasma levels of melatonin in humans, however, they discovered levels that are quite low. It normally takes supplementation of 0.3mg to 0.5mg to effect our blood levels at night in a physiologically significant way.

Unfortunately, the supplements we buy often contain ten times as much as we need – 3mg to 5mg (and often more)!

The Easy Way to Avoid A Melatonin Overdose

Studies have shown that too much melatonin can actually be worse for your condition.  On top of that, it has been demonstrated to have no effect whatever at very high (60mg) levels.

If you are supplementing with melatonin for insomnia, make sure of the dose you are taking. If possible, cut it down to as close to 0.3mg to 0.5mg as you can (I have 5mg pills, so the most I can realistically cut it down to is 2.5mg, which is still too much!).

If one doesn't want to pop a pill, new research seems to indicate that drinking tart cherry juice during the day will naturally raise your body's melatonin levels.  However, this is still under investigation, so proceede with caution and temper expectations.

Is Melatonin Effective For Sleep?

Back in the 1990′s, Melatonin hailed as a wonder-drug that could cure almost everything. The hype got so out of hand that the New England Journal of Medicine in 2000 wrote an editorial that said, in part:

The hype and the claims of the so-called miraculous powers of melatonin several years ago did a great disservice to a scientific field of real importance to human health.

However, there are a few sleep related areas where melatonin is part of a standard therapy, normally combined with strong lighting in the morning, namely to help correct circadian rhythm disorders or abnormalities brought on by work or travel.

The 4 major ones that I'll discuss here are:

1. Delayed Sleep Phase Syndrome
2. Non-24-Hour Sleep-Wake Syndrome
3. Jet Lag
4. Night Shift Work
   

Delayed Sleep Phase Syndrome

The first disorder is called Delayed Sleep Phase Syndrome, or DSPS. It’s also been known as “social jet lag”, because the symptoms are almost exactly like permanently being 4-6 hour jetlagged. This is where your internal bio-clock is stuck an hour or two (or in severe cases, three or four) too late – you aren’t tired enough to sleep until very late in the evening, and then you have a normal sleep until you are woken up too early for you. If allowed to sleep until rested completely, you would wake up a few hours later than most everyone else.

The way this problem is resolved is with melatonin timed in the evening a few hours before normal bedtime combined with light therapy in the morning. In most cases, this will slowly synchronize the body clock with the actual one. The melatonin in this case is not used as a hypnotic sleep inducer, but rather as an internal clock changer (chronobiotic).

Non-24-Hour Sleep-Wake Syndrome

The second is one called Non-24-Hour Sleep-Wake Syndrome and it sounds particularly nasty.

It’s when your body clock (circadian rhythm) is offset an hour or two every night, so you feel sleepy an hour later than you did last night, and wake an hour later – and this goes on and on. So you finish a complete “cycle around the clock” every couple of weeks. And then it starts again.

It’s as though your body takes no cues at all from the time of day that it is – you could be asleep at 5pm and wide awake at 3am. The therapy for this, though, is the same as for DSPS.

Jet Lag

Melatonin is also used for jet lag, and is taken to raise blood melatonin levels before your body would naturally produce them – because you’ve just traveled quickly over a few time zones and it normally takes you one day per zone to naturally adjust to the new light-dark cues. Melatonin taken before bed can “jump start” those cues and make adjusting to the new time easier. Note that the dosage becomes important here, as too much can make you drowsy during the day at your destination.

That said, melatonin’s use for combating jet-lag is controversial. For every study that says it’s effective, there’s another one that says it isn’t. I would say that the only way to tell if it will work for you is to give it a try.

Night Shift Work

The final one would be supplementation for night-shift workers. It can be used as a supplement before going to bed because the day-night cues aren’t there, so the blood melatonin levels aren’t either.

But mostly it’s been touted for another reason – night-shift workers tend to work with artificial lighting, and have very low melatonin levels around the clock (because they’re light-dark cues aren’t there).