Prevent and reduce jet lag symptoms with Melatonin 3mg tablets available to buy online from Dr Fox from 75p each.

Start order

Buy melatonin 3mg online in UK

How to order melatonin online for UK delivery:

  1. Read medical information about melatonin and jet lag
  2. Answer medical questions to check for eligibility
  3. Reviewed by doctors - posted from UK pharmacy (tracked 24hr service)


Prices of Melatonin 3mg tablets from Dr Fox pharmacy (in stock)
30 tablets 60 tablets
Melatonin 3mg £23.80 £45.30

Prescription fees

Dr Fox supplies medicine on prescription and charges a small prescription fee based on the order value of each prescription.

Prescriptions are issued by our doctors online and sent electronically to our pharmacy.

Order value Prescription fee
up to £10 £1.00
up to £20 £2.00
up to £40 £3.00
over £40 £4.00

If you have your own private paper prescription please post to our pharmacy (details).

Dr Fox prices are 25%–50% lower than other UK online clinics.

Delivery charges

UK delivery only: £2.90 per consultation via Royal Mail Tracked 24 Signed For (1-3 working days with tracking).

Parcel forwarding services are not permitted. Use only UK home or work delivery address.

Returns and refunds - unwanted items can be returned within 14 working days for a full refund.

About melatonin

  • Melatonin 3mg tablets are used to treat insomnia caused by jet lag.
  • Take 1-2 tablets at bedtime in the new time zone for up to 5 days.
  • Read the patient leaflet for a full list of side effects, cautions, and interactions with other drugs.

Melatonin tablets contain the synthetic hormone melatonin. Melatonin is naturally produced by the pineal gland in the brain in response to light and dark (day and night). It helps to trigger sleep and regulates the daily body clock. Melatonin 3mg tabs are used for the treatment of jet lag.

In the UK melatonin is a prescription medication. However, in many countries it is classed as a dietary supplement and can be bought in health food shops. Buying melatonin supplements from abroad, e.g. as melatonin 'gummies', is not recommended as they are not authorised for UK sale and therefore unregulated.

Jet lag

Jet lag is caused by disturbance to the body's natural 24 hour rhythm when travelling rapidly between different time zones. Jet lag often lasts a few days but may last up to a week or more. It can cause sleep disturbances, daytime tiredness, loss of concentration and motivation, headache, irritability, reduced appetite, and bloating. It is often unpleasant, and sometimes debilitating, affecting both business and holiday travel. Severity varies from person to person and on the number of time zones crossed, tending to be more severe in older people, and with flights heading East, that cause a 'gain' in time.

It is often quoted that it takes one day per hour of time zone difference for the body to adjust to a new time zone, but this can vary. If travelling to a different time zone for only a few days, some people may cope better by maintaining their body clock, sleep and meal times, to their original time zone.

Melatonin for jet lag

Melatonin was shown to be effective at preventing or reducing jet lag in 8 out of 10 trials reviewed by The Cochrane Collaboration in 2002. The benefit was seen when crossing more than 5 time zones. However, more recent research has given varied results. Melatonin is most effective if crossing at least 2 time zones and is of especial benefit if travelling Eastwards. It's effects are improved if combined with bright light at appropriate times of the day (see below).

How to take melatonin 3mg tablets for jet lag

For adults only - start the tablets on arrival at your destination, not before. Take the first dose (one 3mg tablet) at your usual bedtime in the new time zone. Melatonin should encourage sleep but it is not a sleeping tablet. Further doses are taken at bedtime on the following days for up to a maximum of five days. Tablets should not be taken before 8pm or after 4am. The dose can be increased to two tablets if one tablet is not effective. Tablets should be swallowed whole with water, at least 2 hours before or after food.

If you forget to take the dose at bedtime and wake during the night you may take the forgotten dose, but at no later than 4am. Do not take a double dose to make up for a missed dose.

The 5 day course can be repeated for further episodes of jet lag, but a maximum of 16 courses for jet lag can be taken per year.

If you have taken more than recommended, please contact your doctor, hospital, or pharmacy. Common symptoms of overdose are drowsiness, headache, dizziness, and nausea.

There should be no withdrawal symptoms or harmful effects on stopping melatonin tablets, and the course can be stopped before 5 days, if jet lag symptoms settle more quickly.

How to reduce jet lag without medication

  • Before you travel try going to bed at a time closer to the destination bedtime. Try to make sure you have enough sleep in the days before you travel.
  • Keep as calm and relaxed as possible during travel.
  • Drink plenty to keep hydrated, especially during the flight.
  • Avoid alcohol.
  • Move around during the flight when you can.
  • Adjust the time on your watch to the destination time at the start of the flight.
  • Sleep during the journey only during 'night time hours' on destination time.
  • On arrival try to sleep and eat at destination times.
  • Stay in a dark bedroom during the night, even if you are awake.
  • Try to avoid naps during the day.
  • Spend time out of doors, especially in the afternoons if travelling West, and in the mornings if travelling East, as bright natural light helps with adjustment. Alternatively use a SAD light at these times.

Can anyone take melatonin?

Most people can take melatonin, although people with some pre-existing medical conditions or those taking certain medicines should not take it. Suitability is assessed with a short health questionnaire which is part of the Dr Fox ordering process. Further information is in the patient information leaflet supplied with the tablets. Melatonin is not suitable for under 18s.


Talk to your doctor before taking melatonin medication, if the following apply:

  • Epilepsy - may cause more fits.
  • Autoimmune disease including rheumatoid arthritis, thyroid disease, coeliac disease, where an illness is caused by antibodies to healthy body organs.
  • Diabetes or impaired glucose tolerance (pre-diabetes) - blood sugar levels may increase.
  • Impaired kidney function or liver function.

Smoking may reduce the effect of melatonin medication as smoking can increase the breakdown of melatonin by the liver.

Children and adolescents - not suitable for under 18 years, safety and efficacy are unknown.

Other medicines

The following medications increase the effect of melatonin and should not be taken at the same time:

  • Oestrogen in combined contraceptives (The Pill) or HRT (hormone replacement).
  • Fluvoxamine for depression, OCD (obsessive compulsive disorder).
  • Psoralen as part of PUVA light treatment for skin conditions like psoriasis.
  • Cimetidine rarely used for stomach acid.
  • Quinolone antibiotics rarely used, e.g. ciprofloxacin, moxifloxacin.
  • Other sleeping tablets or remedies.

The following medications decrease the effect of melatonin and should not be taken at the same time:

  • Rifampicin antibiotic for tuberculosis.
  • Carbamazepine for epilepsy, bipolar disorder, and trigeminal neuralgia.

Warfarin may be affected by melatonin, but newer NOAC anticoagulants like dabigatran and apixaban are not affected. Discuss with your GP.

Melatonin tablets with alcohol and food

Alcohol should NOT be taken whilst taking melatonin. Alcohol can impair sleep and potentially worsen certain symptoms of jet lag (e.g. concentration, headache, morning fatigue).

Melatonin should not be taken within 2 hours of food.

Pregnancy, breastfeeding, and fertility

Melatonin should not be taken if you are pregnant or breastfeeding or think you may be pregnant or are planning to have a baby. Melatonin is found in breast milk and crosses the placenta to the foetus. The effects on babies and the unborn are unknown and therefore it is not recommended. Women who might become pregnant MUST use effective contraception if taking melatonin.

Operating machinery and driving

Melatonin can decrease alertness for several hours after intake - do NOT drive, cycle, or operate machinery after taking.

Side effects

Melatonin can cause side effects, but they do not affect everyone.

Serious side effects

Contact a doctor immediately if you develop any of these uncommon but serious side effects:

  • Chest pain (1 in 100).
  • Palpitations, fainting, disorientation, visual symptoms (1 in 1000).
  • Allergic reactions including swelling of the tongue and mouth.

Rarely (1 in 1000) there can be effects on the blood leading to fewer white blood cells or platelets and this may cause bruising, bleeding or blood in the urine, or an increased infection risk. Contact a doctor if you develop any of these symptoms.

Non-serious side effects

Up to 1 in 10 people may experience headache or daytime drowsiness. Sometimes women, and occasionally men, may experience milk leakage from the breasts. More information on side effects is found in the manufacturer's patient information leaflet.

Other uses of melatonin

Dr Fox only supplies melatonin for jet lag. Melatonin is also licensed in the UK as a slow release 2mg tablet (Circadin) for short term treatment of insomnia in adults over 55. There is also an unlicensed, but recognised use to treat insomnia in patients with learning disability or challenging behaviours.

Melatonin has been studied as treatment for a variety of other conditions. These include Gastroesophageal reflux disease (GERD), as a support to cancer treatments (e.g. radiotherapy, chemotherapy), endometriosis, high blood pressure, menstrual pain, general insomnia, shift work related insomnia, frequent urination at night (nocturia), migraine prevention, anxiety before surgery, sunburn prevention, jaw pain from temporomandibular joint problems, age related macular degeneration in the eyes, winter depression (SAD), Alzheimer's disease, tinnitus, and COVID-19. Unfortunately, many of the studies have been in very small numbers of patients and have been unreliable. Dr Fox is unable to supply melatonin for any of these other conditions.

Patient Information Leaflet

Illustration of patient leaflet from medicine packet

The Patient Information Leaflet (PIL) is the leaflet included in the pack with a medicine and must be read before taking the medicine. It is written for patients and gives information about taking or using a medicine.

Melatonin 3mg Patient Leaflet

Melatonin FAQs

Can I get melatonin on the NHS?

Melatonin medication for the treatment of jet lag is considered to be a 'travel medication', and like other travel medicines, is not available through the NHS. It is a prescription medicine which Dr Fox supplies through a private online prescription, posted from our UK pharmacy.

How many tablets do I need?

Treatment is taken for up to 5 days after arriving in a new time zone when one or two tablets are taken each evening. One pack of 30 tablets is enough for up three or six treatments depending on the number of tablets taken each day. Frequent travellers can take up to 16 courses of treatment in a year (maximum 160 tablets per year).

Does melatonin work?

In 2002 The Cochrane Collaboration concluded that melatonin was 'remarkably effective in preventing or reducing jet lag'. They recommended its use especially when travelling East. However more recent research has given more varied results. Adjustment to a new time zone requires the body to adjust its own production of melatonin, and it may be that taking extra melatonin will help you to feel better but slow the body's own adaptation. It is now normally recommended to combine melatonin use with bright light at appropriate times of day, to help with developing more natural melatonin production at the new night time.

My shift work is like jet lag - can I take melatonin?

Unfortunately, there is no licence to use melatonin to help with sleep adjustment during shift work, and Dr Fox does not supply melatonin outside its licence.

There has been some research which suggests that melatonin may be of benefit, but more research is needed. Read further information and hints and tips for shift-workers from the HSE.

Does melatonin help with insomnia?

Melatonin 2mg slow release tablets (Circadin) are licensed for short term (3 to 13 weeks) treatment of insomnia in adults over 55 years. Dr Fox does not supply these tablets.

Further information on insomnia:

See also jet lag FAQs page.

Dr Tony Steele

Authored 14 February 2020 by Dr Tony Steele
MB ChB Sheffield University 1983. Former hospital doctor and GP. GMC no. 2825328

Reviewed by Dr A. Wood, Dr C. Pugh, Dr B. Babor
Last reviewed 12 January 2022
Last updated 19 June 2024


Recent Melatonin reviews

Melatonin rated 4.78/5 in 76 product reviews

See over 40,000 service reviews of Dr Fox


Worked great

03 May 2024
Anonymous Verified


Takes for ages to kick in (2 hrs) however, it does work but you can feel pretty grotty through the rest of the day.

27 March 2024
Anonymous Verified


Really affective and helpful.

05 March 2024
Anonymous Verified


Works very well for me

23 December 2023
N. Pitts Verified


Is ok wasn't the wonder item I thought it would be

19 December 2023
Anonymous Verified

Read more reviews

The order process

Choose medication, register, and pay

Dr Fox issues prescription online

Pharmacy team post medication direct