What’s on this page?
- What is melatonin used for?
- What are the side effects of melatonin?
- Using melatonin in pregnancy
- Melatonin use in children
- Melatonin drug interactions
What is melatonin used for?
Melatonin is a natural hormone released by the pineal gland at night. The pineal gland is a pea-sized gland found just above the middle of your brain and helps the body know when it’s time to fall asleep and wake up. The brain produces melatonin in response to darkness to help us sleep. For this reason, melatonin tablets can be used as a sleep aid that is used when you have trouble falling asleep.
Melatonin plays a role in increasing sleep duration as well as improving the quality of sleep in older adults. It is also commonly used to treat jet lag due to crossing multiple time zones or for shift workers.
Melatonin is a prescription-only medicine in the UK and is not authorised for sale over the counter. In the US, melatonin is considered a dietary supplement and therefore, is less regulated than it is in the UK.
What are the side effects of melatonin?
Melatonin is rarely associated with any serious side effects. Melatonin does not seem to cause addiction, dependence or any withdrawal symptoms. If you take it as prescribed, you’re unlikely to become addicted to it. However, if you have been taking it for a long time you should talk to your pharmacist or doctor if you’re worried about stopping it.
Taking melatonin for short-term use is considered safe. However, it is not recommended to take melatonin supplements for long-term use. Not enough research has been carried out to guarantee that it is safe to be used over a long period and doesn’t cause long term effects.
The most common melatonin side effects are headaches and drowsiness, which can affect people the next day. These may affect up to 1 in 10 people. If you experience these side effects, you should avoid driving or operating machinery. It is also best to limit alcohol intake as alcohol can make drowsiness worse and can impair sleep.
Some uncommon melatonin side effects include dizziness, abnormal dreams, nausea, dry mouth and dry skin. Another uncommon melatonin side effect is weight gain. These can affect up to 1 in 100 people. Side effects like weight gain are more likely to happen if you take melatonin for a long time.
Although rare, there can also be serious side effects (affecting less than 1 in 1000 people). This includes having trouble breathing, unexplained bruising or blood in the urine and chest pains. If you are experiencing chest pains or trouble breathing after taking melatonin you need to be treated in hospital as soon as possible and should call 999.
Using melatonin in pregnancy
Using melatonin in pregnancy or whilst breastfeeding should be avoided as not enough research has been done to ensure that it’s safe for the baby. Melatonin can also pass into breast milk and could potentially cause unwanted side effects. Seek medical advice from your doctor or pharmacist if you are either trying to get pregnant, are pregnant or are breastfeeding before taking melatonin.
Use of Melatonin in children
Melatonin can be prescribed to manage sleep issues in children. Although, it is highly recommended to try other treatments first to fix the child’s sleeping routine such as adjustments to bedtime routine and changing the bedroom environment. If this does not work, only then should melatonin be considered as a treatment. In the UK, melatonin for children is usually prescribed by specialists.
Interactions with other medications
Speak to a pharmacist or a doctor before taking melatonin if you already take one of the following: blood pressure-lowering medications, nonsteroidal anti-inflammatory medications (naproxen, ibuprofen etc.), carbamazepine, warfarin, zopiclone or oestrogens for hormonal replacement therapy. This is due to these medications potentially interfering with melatonin and increasing the risk of side effects or making melatonin less effective.
Avoid taking any herbal remedies that may make you feel sleepy whilst on melatonin. Herbal medicines can increase the sedating effects of the medicine and make you feel drowsier (increasing the risk of daytime sleepiness).
Always inform your doctor or pharmacist of any medications you are taking including any herbal remedies, vitamins, or supplements before starting treatment with melatonin.