Dr Des Corrigan searches for a remedy to cure the symptoms of his jet lag
The Food Safety Authority of Ireland issued an Alert in autumn about a range of five melatonin-containing food supplements, requiring that they be removed from retail or online sale. The Alert was issued on the grounds that the Health Products Regulatory Authority (HPRA) had authorised melatonin as a medicinal product and, as such, it could not be permitted in food supplements.
Melatonin was also mentioned in a National Geographic article in October about natural sleep remedies as possibly the active ingredient in tart (or sour) cherries — sold as a supplement that claims to improve sleep. These two mentions struck a chord with me because I had previously recounted my purchase of melatonin for jet lag in September’s Irish Pharmacist.
My experience of buying melatonin in a discount pharmacy in Perth highlighted, in a small way, differences in practice between here and Australia. Like here, melatonin is prescription-only, but I was able to purchase a pack of 30 tablets, each containing 2mg of melatonin, over the counter (OTC) once I could provide ID showing I was over 55.
I suppose I should have been chuffed to have been asked to prove that I was over 55, but I did feel solidarity with my older grandchildren who regularly have to produce ID. It is also worth mentioning that when I tried to buy some more melatonin to cover my wife and I for our return flight, the pharmacist, after again checking my ID, informed me that I now needed a prescription as I had already had a previous OTC course.
Despite my disappointment, I still admired the commonsense approach. In any event the staff in another friendly pharmacy took one look at me and provided the melatonin OTC without requesting ID!
My mortification at having to prove my age was well worth it though, as both Higher Management and myself felt that the melatonin was a huge help in coping with our jet lag. I realise, however, that a quasi-observational unblinded study with two participants is next to useless from an evidence perspective. I was therefore reassured by the conclusions of a Cochrane Review of melatonin for the prevention and treatment of jet lag, even if it does date to 2002. It found that melatonin taken close to bedtime at your destination decreased jet lag from flights that cross five or more time zones.
While doses of 0.5 to 5mg are equally effective, people fall asleep quicker and sleep better after 5mg. Surprisingly, the review claimed that slow-release formulations containing 2mg were relatively ineffective. Since this was what we had taken, the suspicion of a placebo effect arises. It also appears there is less benefit for passengers on westward flights, such as those from Australia back to Dublin.
The advice from the Cochrane Review was for flyers to take the first dose on the plane soon after it gets dark so as to aid sleep on the way from London to Singapore, with a second dose to be taken at bedtime after arrival in Australia and for a few days afterwards.
But this advice is not much use to the large number of Irish travellers who nowadays avoid Heathrow like the plague and travel via one of the three Middle East hubs from Dublin. What are they to do when faced with a seven- or eight-hour flight to Dubai which, for example, arrives at around midnight local time and connects to an 11- to 13-hour — depending on the Australian city — flight within a couple of hours?
In searching for an answer, I consulted the Summary of Product Characteristic (SPC) for the only product, out of the eight authorised by the HPRA for human use, specifically indicated for the short-term
— maximum five days — treatment of jet lag in adults. Sadly, I did not find anything to help formulate real-world advice to intrepid long-haul travellers, as the SPC (last updated in 2023) echoes the Review in relation to the timing of the dose.
Indeed, it is categorical that the dose (which could, if needed, be doubled from the initial 3mg tablet) should not be taken before 8pm or after 4am at your destination, because of the risk of adverse reactions affecting your ability to adjust to the new time zone. Therefore, taking it after a late night out socialising in either King’s Cross if you are in Sydney or Northbridge in Perth is not advisable.
So, where does the cherry juice come into the story? To be precise, it is the two varieties of the tart cherry (Prunus cerasus), as opposed to the sweet species (P. avium), that contain melatonin. One such variety is the dark-red Morello widely grown in Europe, while the lighter- coloured Amerelle (or Montmorency) is grown in the US.
Several pilot-scale studies in the Journal of Medicinal Food (2010), European Journal of Nutrition (2012), and the American Journal of Therapeutics (2018), suggest a significant improvement in sleeping time and efficiency after drinking tart cherry juice compared to placebo.
Melatonin, naturally present in the juice, was suggested as being responsible for the effect
Melatonin, naturally present in the juice, was suggested as being responsible for the effect. However, analysis showed that the microgram amounts detected in the commercial juice product would be insufficient to explain the activity, so attention has focused on the red- coloured procyanidins that can prevent degradation of tryptophan — also found in the juice — thus contributing to the positive effect on sleep.
Unfortunately, there is, as yet, no study of the effect of cherry juice on jet lag. I did wonder, in a piece of self-serving lateral thinking, if other procyanidins, for example those in red wine, might also be beneficial. To my dismay, the SPC for the 3mg product and also the Cochrane Review, are adamant that alcohol along with caffeine are a no-no on long-haul flights because they accentuate the symptoms of jet lag.
The caffeine I can manage without, but the alcohol ban is a real shame as the airline food in steerage is often made palatable by a glass or two of red. If, however, you are in the fortunate position of booking the premium cabins, then not sampling the higher quality wines on offer requires a superior willpower to mine!
After umpteen trips to Australia since 2008, some involving stopovers but most going straight through to Perth, what advice can I offer about minimising discomfort?
Choose comfortable clothes, especially footwear, invest in noise-cancelling headphones, bring a good book, and set up a playlist of your favourite music on your phone or on the plane’s entertainment system. If you can get a script for melatonin, take some when you board your longest flight and again at bedtime when you arrive.
If it is your first time in the Far East or Down Under, then the exotic sights and sounds will more than compensate you. If you are visiting family, the hugs will more than make up for the discomfort of your journey.
Above all, enjoy the adventure and to hell with the jet lag.
Dr Des Corrigan, Best Contribution in Pharmacy Award (winner), GSK Medical Media Awards 2014, is an Adjunct Associate Professor at the School of Pharmacy and Pharmaceutical Sciences at TCD where he was previously Director and won the Lifetime Achievement Award at the 2009 Pharmacist Awards. He was chair of the Government’s National Advisory Committee on Drugs from 2000 to 2011, having previously chaired the Scientific and Risk Assessment Committees at the EU’s Drugs Agency in Lisbon. He chaired the Advisory Subcommittee on Herbal Medicines and was a member of the Advisory Committee on Human Medicines at the HPRA from 2007 to 2024. He has been a National Expert
on Committee 13B (Phytochemistry) at the European Pharmacopoeia in Strasbourg and served on the editorial boards of a number of scientific journals on herbal medicine.
