L-Carnitine as a Sleep Aid: Don’t Believe the Hype

The compound l-carnitine has its medical uses, but claims that it can help you sleep remain nothing more than that: claims.

Over the years, everything from warm milk to valerian to melatonin have been touted as sleep aids, and the latest chemical to join their ranks is something called l-carnitine. Manufacturers (and there are a lot of them) give glowing reviews as to its efficacy and harmlessness, and so do many users.

But there’s a problem here: like coral calcium and shark cartilage, l-carnitine is unregulated by the FDA as anything more than a dietary supplement. That may sound like a good thing, because it’s easily available without a prescription, but it also means that none of the manufacturer claims have been rigorously tested.

So What’s Up Here?

Also called acetyl-l-carnitine and simply carnitine, this chemical is the love-child of an interaction between the amino acids lysine and methionine. As a relatively new chemical, it’s still undergoing medical testing–and it does show some promise.

Mostly, carnitine is used to treat Alzheimer’s disease, depression, thinking problems, and memory loss associated with age. In about 25% of diabetics who take it, it helps ease neuropathy, a painful nerve damage in the extremities. Perhaps most importantly, it also shows some utility as a pain reliever.

In recent medical studies, carnitine has been tested on patients suffering severe pain from fibromyalgia, cancer, Parkinson’s disease, and other debilitating illnesses. Beneficial effects have been reported–and in fact, it did help the test subjects sleep and battle fatigue somewhat better than they ordinarily did.

Sounds Like a Sleep Aid to Me!

Unfortunately for the insomniac, the beneficial effects of carnitine are due primarily to the fact that it eases pain somewhat. When the pain eases off, the critically ill patients in the abovementioned studies could sleep better.

In healthy individuals, the compound works no better than a placebo–which is to say that it does sometimes work, because those who take it believe it should. There are also anecdotal accounts of its efficacy, but anecdotal evidence isn’t good science.

It’s good enough for marketers to claim carnitine works, though–which is why you can find it for fairly outrageous prices in health food stores and nutrition centers all over the county.

Leave It In the Store

If you really want to sleep, read a Russian novel, try some warm milk, or better yet, down some Sominex. While acetyl-l-carnitine does in fact help some critically ill people sleep, that’s a secondary side effect of its pain relief properties. There’s no firm evidence, as of yet, that l-carnitine is effective as a general sleep aid.