Melatonin should not be prescribed for jet lag on the NHS because there is little evidence it makes any real difference, an evidence review has concluded.

Two melatonin products for short-term use in jet lag were approved by the Medicines and Healthcare Products Regulatory Agency last year.

But a new review, published in the Drug and Therapeutics Bulletin, concluded there remain a lot of unanswered questions about the use of melatonin in jet lag.

The review points out that because melatonin had already been licensed for jet lag within the EU for a period of 10 years, the manufacturer did not need to supply any new evidence about the preparation of the new products, which could affect its efficacy.

Available studies, most of which were small, show only a moderate effect from the drug on jet lag and report a range of adverse effects, the review said.

It concluded that melatonin – which costs £10.83 for a short course of tablets – should be added to the list of drugs that GPs cannot prescribe on the NHS.

Limited evidence of benefits

‘Since jet lag is a self-limiting short-term problem and there is limited published evidence of the benefit of melatonin on symptoms, we do not think that it is appropriate for such a product to be made available through the NHS,’ the review said.

‘We would suggest that melatonin for jet lag is added to the list of drugs that may not be ordered under a General Medical Services contract.’

The symptoms of jet lag can include disrupted sleep, fatigue, mental fog and gut disturbances, and seem to be worse when travelling eastwards.

Data from openprescribing.net, which analyses NHS data, shows a steady increase in prescriptions in the past few years - although the drug is also used for insomnia.

A clinical knowledge summary by the National Institute for health and Care Excellence on jet lag that was updated in 2019 - but before melatonin was marketed for the treatment of jet lag - did not recommend its use.