Circadin

What is Circadin?

Circadin contains melatonin,  a hormone produced naturally by the body which regulates your sleep cycle. It increases at nightfall and decreases as the sun rises, causing you to fall asleep during the night. Circadin capsules can help ease jet lag and insomnia, where you have difficulty sleeping or staying asleep at normal times. 

Circadin contains melatonin, a hormone produced naturally by the body which regulates your sleep cycle. It increases at nightfall and decreases as the sun rises, causing you to fall asleep during the night. Circadin tablets can help ease jet lag and insomnia, where you have difficulty sleeping or staying asleep at regular times.

How does Circadin work?

Circadin works by regulating your sleep-wake cycle. As it gets dark at night, this causes melatonin levels to rise, preparing the body for sleep. Melatonin levels drop as daylight arises, causing you to wake up. During jet lag, your natural melatonin levels are disrupted as your body adjusts to a different time zone. If you have insomnia, you may have a reduced level of the melatonin hormone. Circadin works by balancing out your sleep-wake cycle to help you sleep. 

How long do Circadin tablets last?

The effects of Circadin generally lasts for up to 8 hours, depending on the dose taken.

Circadin for insomnia

Insomnia is a relatively common sleep disorder and affects around one-third of the UK population at some point in their lives. Studies have shown that Circadin has proven effective in helping people with insomnia fall asleep and get a restful, healthy sleep. While the supplement can aid the onset of sleep, it does not provide a cure for insomnia. Cognitive Behavioural Therapy can help identify the root cause of insomnia and change your behaviour and thinking to improve your sleep.

Circadin for seasonal affective disorder

There is evidence to show that Circadin can help people suffering from Seasonal Affective Disorder (SAD). Often referred to as winter depression, the change in season triggers low mood and a lack of energy. In people with SAD, it's thought that the natural level of melatonin increases, making you feel tired and sluggish during the day. If you are having trouble sleeping at night because of Seasonal Affective Disorder, then Circadin may help with this.

Is Circadin for jet lag off-label use?

Circadin was initially licensed for use in insomnia. Despite the evidence, this license was not extended to cover using Circadin for jet lag. Therefore, jet lag is an ‘off-label’ use of Circadin. This does not mean that it would be unsafe to use Circadin in this way, but rather that the manufacturers decided not to apply to extend the license, which can be a costly process. Doctors can prescribe drugs off-label, where they are the most appropriate treatment available. The NHS has created a document to explain more about off-label use, which you can access here.

Active ingredients

The active ingredient in Circadin is melatonin. Each tablet contains 2mg melatonin.

Inactive ingredients

The inactive ingredients are ammonio methacrylate copolymer type B, calcium hydrogen phosphate dihydrate, lactose monohydrate, silica (colloidal anhydrous), talc and magnesium stearate.

Which ingredients can cause an allergic reaction?

Circadin is a medication containing a naturally occurring hormone in our body called melatonin. In rare cases, Circadin can result in a serious allergic reaction. Signs of a serious allergic reaction include hives, chest tightness, trouble breathing and dizziness. Please get immediate medical attention if you notice any of these after taking the medication.

How to take Circadin?

Circadin should be taken with food one to two hours before going to bed once each day for up to thirteen weeks.

Can Circadin tablets be crushed or split?

Circadin is a slow-release tablet and should not be crushed or split as this prevents it from working correctly.

Circadin side effects

Common side effects may include: 

• Headaches
• Back pain
• Throat inflammation 
• Weak muscles 

Less common side effects may include: 

• Migraines 
• Feeling irritable, nervous or restless 
• Dizziness
• Abdominal pain
• Drowsiness 
• Dry mouth
• Constipation
• Abnormal dreams 
• Sweating 
• Weight gain 
• Hyperbilirubinaemia

Rare side effects may include: 

• Mood changes
• Feelings of aggression 
• Increased sex drive
• Problems with attention or memory 
• Blurred vision
• Upset stomach
• Hot flushes 
• Night sweats 
• Priapism
• Skin rashes

Contraindications

You should not use Circadin if:

• You have liver problems
• You are under 18 years old
• You have an autoimmune disease 
• You have Galactose intolerance or glucose-galactose malabsorption
• Consult your doctor if you have decreased functioning of the kidneys.

Drug interactions

The following medications can interfere with the way Circadin is broken down by the body and should not be taken at the same time: 

• Cimetidine
• Fluvoxamine
• Psoralen
• Quinolone antibiotics 
• Contraceptives or hormone replacements containing oestrogen
• Psoralen
• Carbamazepine 
• Rifampicin 

The following medications can increase drowsiness when taken in conjunction with Melatonin: 

• Benzodiazepines
• Antipsychotics
• Sleeping tablets
• Tricyclic antidepressants 

Circadin and pregnancy

It is not recommended to take Circadin during pregnancy as it has not been determined if this is safe or not.

Circadin and alcohol

Alcohol should be avoided when taking Circadin as it can increase drowsiness and dizziness.

What is the difference between Melatonin and Circadin?

Circadin is a brand name medicine which contains melatonin. Melatonin exists as a generic brand without the name ‘Circadin’. They contain the same active ingredient ‘melatonin’ but may differ in other components that make up the tablets.

Circadin vs Melatonin supplements

It is safest to take Circadin (Melatonin) if a doctor has prescribed it as they will provide you with directions on how much to take, and how to take it correctly for your individual needs. If you purchase melatonin supplements, the amount of melatonin present in the product may vary as may the additional ingredients.

Jet lag tips

Jet lag cannot be prevented as travelling to different time zones upsets your body’s natural circadian rhythm. However, to reduce tiredness, you can gradually ease your way into the altered time zone of the destination you are travelling to by going to bed slightly later or setting your alarm earlier than usual. Try to move around during your flight if you can to get a bit of exercise, stay hydrated and avoid caffeine and alcohol as these substances will disrupt your sleep.

Is Circadin safe for regular use?

Circadin can be taken safely for up to thirteen weeks. However, continued use can lead to side effects, including mood disorders and drowsiness. The safety of taking Circadin long term is not yet known, so it's recommended as a short term solution only. 

Is Melatonin natural?

Melatonin is a hormone produced naturally by the body. Circadin and Melatonin supplements contain a synthetic version of the hormone and are not naturally occurring.