Melatonin for jet lag; does it work and is it safe?
Melatonin is a hormone made by the pea-sized pineal gland within the brain and its production is triggered by darkness and inhibited by light. In other words, it is not a sleep hormone but simply a marker of darkness and its release helps to prepare the body for sleep. However, in supplement form, it is often, controversially, mentioned as a “cure” for jet lag. Indeed its use in America has doubled in the last 5 years, whereas here in the UK, it is not available over the counter.
The inconvenience of jet lag with long-distance travellers very often calls for measures to counter the debilitating effects of finding your internal body clock out of sync with local time. After all, arriving on business to meet with clients, deliver an important presentation or secure the next business contract can be severely hampered if lack of sleep has left you lethargic and less alert.
So is Melatonin safe and does it work for jet lag?
Scientifically, it is unclear how melatonin may induce sleep more quickly. However, some research suggests that as it can dilate blood vessels near the skin, it therefore also lowers body temperature, which can make you more sleepy. That said, when studying circadian rhythms, researchers are convinced that it can be used to help re-align the internal body clock when they fall out of sync in cases of shift work or jet lag. The problem is knowing the right time to take it and if not taken at the right time, it can increase drowsiness.
A 2002 Cochrane review analysing people crossing 5 or more time zones, who take melatonin close to bedtime at their destination, did conclude melatonin to be effective in preventing or reducing jet lag; showing less severe symptoms than those taking placebos and occasional short-term use appears to be safe. However, there are interactions and possible harmful effects for people with epilepsy or those taking blood-thinning medication such as Warfarin.
So, it seems the research is neither absolutely conclusive not damning, but it is worth pointing out that Melatonin, bought as a nutritional supplement outside of the UK is not subject to the same strict standards as prescription medication.