Medication features:

  • A prescription-only medicine
  • The only licensed melatonin medication available in the UK
  • Can be taken to assist with insomnia


Available strengths:



Price £19.99

Includes free private prescriptions

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Expected delivery date:

Wednesday, 13 December 2023

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Discreet & Confidential

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  • Overview
  • FAQ
  • Side Effects
  • Patient Information Leaflet
  • Reviews

What is Circadin

Circadin (Melatonin) is a prolonged release melatonin supplement which can be taken to assist with insomnia and, after the positive effects on jet lag were studied in the Cochrane Review, it can also be used by anyone suffering from sleep issues after changes in time zones due to long flights.

The hormone melatonin is released naturally from the pineal gland during the evening and through the night to help you get to sleep, and stay asleep whilst it is dark. During the day when it is light, melatonin production is suppressed, and this is how the body regulates its sleep/wake cycle.

After crossing into different time zones, the time you would normally start thinking about going to bed, around 8 pm or 9 pm, may now be the middle of the afternoon or night in the country you have travelled to. As such, your body clock becomes confused as at first, melatonin still naturally begins to be produced around the same time as normal. This is your normal circadian rhythm which is a twenty four hour cycle during which physiological processes naturally occur such as going to sleep and waking up. You can wait until your jet lag passes naturally and your body gets back in line with its new time zone, but this can take several days. As such, some people find enormous benefit in using a melatonin supplement to help top up the body when it is not producing this hormone at the right time, or enough of it, to induce sleep.

How effective is Circadin?

In trials, Circadin was shown to effectively secrete melatonin over several hours, which enabled patients to enjoy a natural sleep cycle despite disturbances due to external influences such as jet lag.

When you are shifting between time zones, one study also showed that small doses of melatonin, such as that found in Circadin, can help travellers overcome jet lag more quickly and with fewer issues. This could account for why 1.3% of American adults take melatonin for jet lag and other sleep disorders, a number which more than doubled between 2007 and 2012.

Can I buy Circadin Online?

Circadin is prescription only as it has been approved by regulatory medicine authorities after trials showed it to be clinically effective for anyone suffering from some form of insomnia. If you wish to purchase Circadin prior to a long-distance trip, you will need to fill in a quick questionnaire which will enable the health experts at Click Pharmacy to confirm whether this medication is safe and/or necessary. Once prescribed, you can purchase Circadin online, and it will be sent out via next-day delivery where possible.

What are the side effects of Circadin?

Some people may find that they experience certain side effects when using Circadin though it is considered to be unlikely. As when starting to take any medication, it is important to remain vigilant and aware of any changes with your health. If you notice any of the following and find them to be affecting your health or worrying you in any way, speak to your doctor or pharmacist to get advice.

The following have been known to occur in around 1 in 100 patients, which is medically considered to be ‘uncommon’ so do not be alarmed by this list:

  • Feeling: irritable, nervous, restless, anxious, nauseous, weak, dizzy or lethargic.
  • Experiencing: chest pain, insomnia, abnormal dreams and nightmares, migraines and headaches, high blood pressure, (upper) abdominal pain, indigestion, mouth ulcers, jaundice, night sweats, pruritis, itching, rashes, dry skin, pain in extremities or menopausal symptoms.

Different people will have a unique reaction to the medication, so tell your doctor if you notice any of the above or any other issues as soon as possible.

Why choose Circadin?

Circadin is presently the only licensed melatonin medication available in the UK, and although other quick-release products are available online, they are not licensed here. It has been shown that these quick-release products can affect blood pressure negatively, causing it to peak, whereas Circadin offers a gentle, slow release of melatonin throughout the course of several hours, which helps your body clock to safely, naturally and effectively get itself back on track, easing sleep issues such as jet lag and insomnia.

What is contained in Circadin?

Circadin’s active ingredient is melatonin.

The inactive ingredients include:

  • Ammonio methacrylate copolymer type B
  • calcium hydrogen phosphate
  • lactose
  • colloidal anhydrous silica,
  • purified talc
  • magnesium stearate

Tell your doctor if you know you suffer with allergies to any of the above.

How should I take Circadin?

It is advised that patients take Circadin after a light meal and around 1 to 2 hours before bed, which is roughly the same time your pineal gland would naturally begin to produce melatonin to help you begin to feel tired. A quicker release of the active ingredient will occur if taken on an empty stomach.

Follow the instructions in the patient leaflet and/or any recommendations given to you by your GP, or Click Pharmacy doctor for best results.

How does Circadin work?

Once taken, the formulation releases melatonin steadily for anywhere up to 10 hours, allowing you to enjoy a natural sleep pattern during this time. It helps by adding an external source of melatonin to the natural source already secreted from your pineal gland, which may be limited in someone suffering with jet lag or insomnia. This additional melatonin facilitates a sense of tiredness, eases the ability to get to sleep and stay asleep and improves the overall quality of sleep, which in turn helps patients experience a better quality of life overall.

Can I take Circadin whilst breastfeeding?

The effects of Circadin have not been studied in pregnant or breastfeeding women, and as such, it cannot be recommended as safe at this time. If you are struggling with insomnia or jet leg whilst pregnant or breastfeeding, book a free and confidential consultation to discuss your options from the comfort of your home with a Click Pharmacy doctor.

What are the benefits of taking Melatonin?

Melatonin is ideal for individuals with sleeping problems. Typically, people with sleeping disorders use melatonin. Melatonin is essential in helping individuals who suffer from a delayed sleeping disorder. Additionally, it is incredibly beneficial for people whose jobs disrupt their normal sleep schedules.

Alternative methods to treat Jet Lag

Circadin is one of the few natural choices available in the UK that help improve symptoms of Jet Lag. Of course, you can take other sleeping tablets at night. That may also improve your sleep quality after flying, but it can also cause severe side effects. In addition to this, such medicines can be highly addictive.

The most practical ways to decrease the intensity of symptoms of jet lag are:

Avoid taking naps while travelling.

Try to go to sleep at a normal hour in the new time zone

Stay outdoors as much as possible, as natural light is known to help speed up the process.

Try to eat at normal hours for your new time zone rather than the one you are used to at home.

What is the active ingredient in Circadin Tablets?

The active ingredient in Circadin Tablets is melatonin.

Can I drive after taking Circadin Tablets?

No, you should not drive or operate machinery after taking Circadin Tablets. This is because the active ingredient, melatonin, controls the sleeping pattern making you feel sleepy. This makes it unsafe to drive or operate machinery, as these activities require full concentration.

Can pregnant or breastfeeding women take Circadin Tablets?

Due to the lack of research, it is advised that pregnant or breastfeeding women do not take Circadin Tablets. This is because there has not been enough research to see whether the active ingredient, melatonin, affects the baby in any way.

How long does it take for Circadin Tablets to work?

Circadin Tablets usually begin working within 1-2 hours.

Will taking Circadin Tablets cause me to sleepwalk?

Taking Circadin Tablets does not cause one to sleepwalk. If you experience sleepwalking after taking Circadin Tablets, stop taking the medication and consult a GP or pharmacist immediately.

Can I drink alcohol while taking Circadin Tablets?

No, you should refrain from drinking alcohol while taking Circadin Tablets. This is because alcohol can cause sleepiness, combining it with Circadin Tablets may result in you sleeping so deeply to an extent where your breathing is affected.

Although most people do not experience any side effects after taking Circadin Tablets, possible side effects and how to treat them include:

  • Headaches: ensure you are drinking plenty of water to remain hydrated. If you experience severe headaches, consult a GP or pharmacist who may be able to recommend a painkiller.
  • Nausea: to prevent any nausea like feeling it is advised to take Circadin Tablets after a meal or heavy snack.


Always read the patient information leaflet before starting your treatment. The patient information can be found here.

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