Circadin is a prolonged-release tablet containing 2mg of melatonin. It is the first in a new class of drugs known as melatonin receptor agonists. Circadin is a prescription only drug and is used in the treatment of insomnia and jet lag.
Melatonin is a hormone that is naturally produced in our body by the pineal gland in the brain. It is normally secreted every night when daylight ceases and darkness sets in. This leads to a decrease in brain activity making us drowsy, less alert, and unable to concentrate. Melatonin is usually not produced in the daytime because its presence in the blood stream is meant to prepare us for sleep.
Melatonin also causes hormones and oxygen to be withdrawn from the cells and muscle tissue making it more difficult to be physically active. Thus we become withdrawn, tired, and want to sleep.
When we suddenly shift to a new time zone, our production of melatonin no longer coincides with our schedule; we feel tired when we don’t want to sleep, and don’t feel tired when we want to sleep. It takes a number of days for our internal clock to adjust. Taking Circadin will help the body’s internal clock to adjust to the new time zone, thus reducing the effects of jet lag.
The melatonin in Circadin works in exactly the same way as natural melatonin, by acting on the melatonin receptors in the brain. It has been shown to reduce the time it takes to fall asleep as well as improving the quality of sleep and morning alertness.
The side effects of Circadin are minimal if it taken as directed. Any effects seen are usually temporary and will disappear once you have stopped taking it.
Some of the most commonly reported side effects include:
- Mood changes
- Decreased sex drive
- Daytime fatigue
- Vivid dreams or nightmares
The patient information leaflet (PIL) is a leaflet containing specific information about medical conditions, doses and side effects. You can download a copy of the PIL here:
Patient Info Leaflet