Melatonin in the UK: the rules and the alternatives

Can you buy melatonin in the UK?

No. In the UK, melatonin is a prescription-only medicine, so shops, pharmacies and websites can't sell it to you without a prescription. The melatonin supplements sold in other countries, gummies included, are not authorised for sale here [1].

The NHS advises against ordering melatonin online [1]. You can't be sure what an unlicensed product contains. When researchers tested 31 melatonin supplements, the melatonin content ranged from 83% less to 478% more than the label said [2].

Why is melatonin banned in the UK?

It isn't banned, but it is classed as a medicine, not a food supplement. The MHRA, which regulates medicines, told Which? in 2026 that melatonin "is considered to pose an identifiable risk to public/patient safety due to its ability to exert significant modification to human physiology" [3].

The MHRA also said any product containing melatonin, skin patches and skincare included, counts as a medicine. Even so, Which? found melatonin listed on UK online marketplaces between October 2025 and January 2026, one product at 30 mg, three times the NHS maximum of 10 mg [3].

What does melatonin do?

Melatonin is a hormone your body makes to help control when you sleep. Levels rise after dark, peak in the early hours and fall during the day [1].

A melatonin tablet adds to your body's own supply. The NHS says this can help you fall asleep more quickly and make you less likely to wake in the night. It may also ease jet lag [4].

Can a GP prescribe melatonin?

Yes, but mainly for adults aged 55 and over with short-term sleep problems. Specialists sometimes prescribe it for longer-term sleep problems in some children and adults [4].

• Adults 55 and over. Usually one 2 mg slow-release tablet, 1 to 2 hours before bed, for 1 to 4 weeks and at most 13 weeks [5].
• Longer-term sleep problems. A specialist may prescribe it for longer, sometimes at a higher dose [5].
• Jet lag. Adults can be prescribed 3 mg tablets for up to 5 days, but this may not be available on the NHS [1, 5].

If you're under 55 and sleep badly now and then, your GP is unlikely to prescribe it. They're more likely to suggest the habits and therapy covered below.

How long does melatonin take to work?

About 1 to 2 hours, the NHS says, which is why the usual tablet is taken 1 to 2 hours before bed. The slow-release tablet then releases melatonin gradually through the night [4, 5].

If you still have sleep problems when your course ends, the NHS suggests trying lifestyle changes, then seeing your doctor again if they don't help [1].

Does melatonin work?

It helps a little. In a review of 19 trials with 1,683 people with sleep disorders, melatonin helped people fall asleep about 7 minutes sooner and sleep about 8 minutes longer than a placebo [6]. The researchers called the effects modest.

The slow-release form prescribed in the UK shows a similar picture. A 2023 review of 22 studies in adults with insomnia found that slow-release melatonin helped people fall asleep about 5 to 6 minutes sooner than a placebo. Sleep efficiency improved more in groups with an average age of 55 or over [7].

Is melatonin safe?

For most people taking it as prescribed, yes. The NHS says most people get no side effects, and serious ones are rare, affecting fewer than 1 in 1,000 people. The common ones include [10]:

• daytime sleepiness, headache and dizziness
• stomach ache and feeling sick
• irritability, strange dreams or night sweats

Don't drive or cycle if it makes you sleepy or dizzy. Avoid alcohol and caffeine while you take it [1].

How can you fall asleep faster?

Change your sleep habits first. The NHS says insomnia usually gets better this way, and suggests [12]:

• Get up at the same time every day, and only go to bed when you feel sleepy.
• Relax for at least an hour before bed, with a bath or a book.
• Keep your bedroom dark and quiet. Curtains, an eye mask or earplugs can help.
• Have no alcohol, tea or coffee for 6 hours before bed, and no exercise for 4 hours before.
• Put your phone away before bed, and don't nap during the day.
• Don't sleep in after a bad night. Stick to your usual hours.

We found no good evidence for tricks that send you to sleep in minutes. These habits work over days and weeks.

If habits alone don't help, a GP may offer cognitive behavioural therapy (CBT), face to face or as an online programme [12]. NICE calls CBT for insomnia the standard first treatment for long-term sleep problems, after advice on sleep habits [13]. See your GP if you've had trouble sleeping for months, or it's making daily life hard to cope with [12].

What can you take to help sleep?

Without a prescription, your options are short-term pharmacy sleep aids and food supplements such as magnesium and ashwagandha. They work best alongside good sleep habits.

Pharmacy sleep aids

Pharmacies sell sleep aids, some with valerian or lavender and some with an antihistamine. The NHS says they may help for 1 to 2 weeks and shouldn't be taken for longer. Some cause drowsiness the next day [12].

Magnesium

Magnesium is a mineral sold freely as a food supplement. In a 2025 trial of 155 adults who slept poorly, 250 mg a day improved sleep scores a little more than a placebo after 4 weeks [9]. Our guides to magnesium for sleep and magnesium glycinate cover forms, doses and timing.

Ashwagandha

Ashwagandha (Withania somnifera) is a herb used in Ayurveda. A 2021 review of 5 trials with 400 adults found a small improvement in sleep [8]. If you've been prescribed melatonin, don't add ashwagandha unless your GP agrees. Our complete guide to ashwagandha covers who should avoid it.

Where Nooroots fits

Nooroots doesn't sell melatonin. We make food supplements for everyday routines.

Ashwagandha + Lion's Mane gives you 120 mg of KSM-66 ashwagandha and 500 mg of lion's mane extract in two caffeine-free capsules a day, for calm focus and calm resilience on demanding days.

Triple Magnesium gives 301 mg of magnesium in three capsules, made for the evening. Magnesium contributes to the normal functioning of the nervous system and to normal psychological function. Coming soon. Triple Magnesium isn't on sale yet.

Frequently asked questions

Can I take 10 mg of melatonin?

Only if a specialist prescribes it. The usual UK dose is one 2 mg slow-release tablet, and the NHS lists 10 mg once a day as the maximum, for longer-term sleep problems under a specialist [5].

Is 20 mg of melatonin too much?

It's twice the highest daily dose the NHS lists, which is 10 mg [5]. Only take what your doctor prescribes, and don't buy high-dose products online [1].

Can you overdose on melatonin?

The NHS says 1 or 2 extra tablets are unlikely to harm you. If you've taken more than your prescribed dose and feel unwell, contact 111 [5].

Is melatonin addictive?

The NHS says you're unlikely to become addicted if you take it as prescribed. If you've taken it for a long time, ask your doctor or pharmacist how to stop gradually [1].

Can you take melatonin with alcohol?

No. The NHS says alcohol and melatonin together can make you sleep so deeply that you don't breathe properly and find it hard to wake up [1].

Do melatonin gummies work?

Melatonin gummies aren't authorised for sale in the UK, so there's no licensed version to judge [1]. Supplements sold abroad often don't contain the amount on the label [2].

References

Every source here is listed so you can read it yourself. This guide is for general information and doesn't replace advice from your GP or pharmacist. We review it when new research or guidance is published.

1. NHS. Common questions about melatonin. Page last reviewed 13 February 2023. Accessed 17 October 2026. nhs.uk/medicines/melatonin/common-questions-about-melatonin
2. Erland LA, Saxena PK (2017). Melatonin natural health products and supplements: presence of serotonin and significant variability of melatonin content. Journal of Clinical Sleep Medicine 13(2): 275–281. doi:10.5664/jcsm.6462
3. Thomas M (10 February 2026). Sleep drug melatonin illegally listed for sale on online marketplaces including Superdrug. Which? (includes the MHRA's statement on why melatonin is prescription-only). which.co.uk/news
4. NHS. About melatonin. Page last reviewed 13 February 2023. Accessed 17 October 2026. nhs.uk/medicines/melatonin/about-melatonin
5. NHS. How and when to take melatonin. Page last reviewed 13 February 2023. Accessed 17 October 2026. nhs.uk/medicines/melatonin/how-and-when-to-take-melatonin
6. Ferracioli-Oda E et al. (2013). Meta-analysis: melatonin for the treatment of primary sleep disorders. PLOS ONE 8(5): e63773. doi:10.1371/journal.pone.0063773
7. Maruani J et al. (2023). Efficacy of melatonin and ramelteon for the acute and long-term management of insomnia disorder in adults: a systematic review and meta-analysis. Journal of Sleep Research 32(6): e13939. doi:10.1111/jsr.13939
8. Cheah KL et al. (2021). Effect of Ashwagandha (Withania somnifera) extract on sleep: a systematic review and meta-analysis. PLOS ONE 16(9): e0257843. doi:10.1371/journal.pone.0257843
9. Schuster J et al. (2025). Magnesium bisglycinate supplementation in healthy adults reporting poor sleep: a randomized, placebo-controlled trial. Nature and Science of Sleep 17: 2027–2040. doi:10.2147/NSS.S524348
10. NHS. Side effects of melatonin. Page last reviewed 13 February 2023. Accessed 17 October 2026. nhs.uk/medicines/melatonin/side-effects-of-melatonin
11. NHS. Taking melatonin with other medicines and herbal supplements. Page last reviewed 13 February 2023. Accessed 17 October 2026. nhs.uk/medicines/melatonin/taking-melatonin-with-other-medicines-and-herbal-supplements
12. NHS. Insomnia. Page last reviewed 19 March 2024. nhs.uk/conditions/insomnia
13. NICE (2023). Daridorexant for treating long-term insomnia. Technology appraisal guidance TA922 (see "Why the committee made these recommendations"). nice.org.uk/guidance/ta922