Melatonin jet lag 'cure' dismissed
February 09, 2006
Press Association

There is no evidence that the hormone melatonin is effective in combating jet lag or treating other sleep problems, researchers have said.

Many travellers and shift workers swear by melatonin tablets, claiming they help them deal with sleep deprivation and interrupted sleep.

But now a review by researchers, writing online in the British Medical Journal, has found no evidence that the hormone is effective in tackling such sleep disturbance.

Melatonin is available over-the-counter in the United States and is widely available over the internet. It is not so readily available in the UK but doctors are able to prescribe it "off licence".

Melatonin is produced in the body mainly during the night, as a secretion from the pineal gland in the brain. It is associated with many effects which are concerned with the timing of biological functions in the body.

The researchers from the University of Alberta in Canada analysed numerous trials on the effects of melatonin in people with secondary sleep disorders - problems linked to medical complaints or substance misuse.

"There is no evidence that melatonin is effective in treating secondary sleep disorders or sleep disorders accompanying sleep restriction, such as jet lag or shiftwork disorder," the researchers concluded.

"Although the increase in sleep efficiency in people with secondary sleep disorders was statistically significant with melatonin, the effect was small - 1.9% - an increase of less than 10 minutes in the amount of time spent asleep for eight hours spent in bed.

"On the basis of advice from clinical sleep experts, we considered this effect to be clinically unimportant due to its small magnitude."

The researchers said the evidence showed that melatonin was safe for short-term use, but more research was needed to determine its long-term safety.