Melatonin is a hormone which is produced naturally by the body during darkness and is thought to play a big role in controlling how and when people sleep.
The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) last year published a new rule allowing doctors to prescribe it for jet lag.
But researchers now argue there are too many ‘unanswered questions’ about it – they say it doesn’t stop jet leg, causes side effects like headaches and feeling sick, and can cause seizures in people with epilepsy.
It had started being used because past studies found taking it can reduce symptoms such as tiredness and brain fog and it’s thought to help the body clock stay in time.
The scientists said it isn’t worth prescribing it because jet lag clears up on its own within a few days so doesn’t need medication.
Melatonin could reduce the symptoms of jet lag, according to past research, but it does not stop the condition completely and may have negative side effects such as headaches and feeling sick, researchers said (stock image)
‘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,’ said experts at the scientific journal, Drug and Therapeutics Bulletin.
Jet lag is the name given to a tired, groggy feeling and difficulty sleeping normally that people get when they fly to different time zones.
Travellers may find their body clocks are out of sync with day and night at their destination and that this has physical impacts on their health.
Researchers reviewed 10 past studies and four reviews of other studies into the benefits and drawbacks of melatonin taken from between 1986 and 2005.
They found that melatonin did appear to reduce people’s jet lag symptoms – those who took it rated their symptoms a 27 out of 100, with 100 being the worst, while those who took a placebo – a fake pill – rated their jet lag 47 out of 100, on average.
But taking the medication doesn’t get rid of the condition completely.
WHAT IS JET LAG?
Jet lag is a condition which people develop after travelling to different time zones on long-haul flights.
It is caused by the body’s internal clock, which dictates when you feel alert, hungry and sleepy, being thrown out of sync with the daylight hours where you’re staying.
Getting sunlight at unusual times, such as when your body naturally expects it to be night, can disrupt the hormone melatonin, which regulates the sleep-wake cycle.
The more time zones someone crosses, the more likely they are to get jet lag.
And it’s thought to be worst if people are travelling east – hours get later in that direction so they ‘lose time’.
Symptoms of jet lag include feeling sleepy during the day, being unable to sleep at night, stomach problems and constipation or diarrhoea, feeling unwell and difficulty concentrating.
Jet lag usually clears up on its own within a couple of days.
To avoid it, experts suggest getting a lot of rest before travelling; spending a couple of days re-timing your schedule to match times at your destination; and sleeping on the plane if it is night where you’re going.
And melatonin could increase the risk of seizures in people with epilepsy, the researchers found.
While people with autoimmune conditions such as Crohn’s disease are not recommended to take it because it can make the immune system more active.
The drug may also reduce the effectiveness of other drugs like contraceptives, diabetes medicines, blood-thinners and anti-epilepsy medications.
The Drug and Therapeutics Bulletin researchers added: ‘Overall, melatonin appeared to have a modest effect on symptoms of jet lag compared with placebo.
‘Adverse effects reported with melatonin include headache, nausea, drowsiness and sedation.’
Melatonin is available for jet lag on the NHS in 3mg tablets, which cost the health service £10.83 for a five-day course, or an oral solution which costs £13.
It is generally prescribed for insomnia – overall, melatonin products were prescribed 974,122 times in 2017/18 at a cost of £35,968,140 to the NHS.
The Drug and Therapeutics Bulletin researchers said they were worried that expanding the list of conditions for which it could be prescribed might end up with it being overused.
Dr James Cave, the journal’s editor, added: ‘I have concerns… that you will get licence creep, and that it will be used for people with sleep problems in general, and it’s not really a good way of dealing with those.’
The review was published in the