This website has moved to a new location. Please visit our sister website for next day delivery.
  • Prescription included
  • Genuine medication
  • All-inclusive service - No hidden fees
  • Free next-day delivery
Home / Insomnia / Melatonin side effects and how to manage them

Melatonin side effects and how to manage them

Learn how to manage the common and uncommon side effects of Melatonin

Melatonin is a hormone that your brain naturally produces in response to darkness. It is used as a sleep aid to help regulate sleep patterns. Melatonin can also be made synthetically into products such as tablets or dietary supplements, such as gummies.

Melatonin tablets work by binding to receptors in your body, which help to regulate your circadian rhythm (your internal clock) and sleep.

Image of a clock, pills, a sleeping mask and a glass of water

Melatonin products may help with conditions, such as jet lag, delayed sleep-wake phase disorder, some sleep problems in children, and anxiety before and after surgery.

Is Melatonin safe?

Melatonin is naturally produced by the body and is generally safe for short-term use. However, like all medications, it can cause adverse effects and may not be suitable for some people.

Common side effects

In clinical trials Trusted source electronic Medicines Compendium (eMC) Government Source UK Government Medicine Info Site Go to source , 48.8% of patients receiving Melatonin reported that they experienced a side effect compared with 37.8% of patients taking the placebo (inactive drug).

The most common side effects are listed in the table below.

Common side effects
  • headache
  • a common cold
  • back pain
  • joint pain

Feeling tired or sleepy

Melatonin is intended to help with trouble falling asleep, staying asleep, or poor quality of sleep. Therefore, feeling tired or sleepy is expected.

Sometimes, the effects of Melatonin can continue the next day, resulting in daytime sleepiness. If this happens, avoid driving or using tools or machinery.

Image of a woman yawning and stretching


If you experience a headache when taking this medicine, make sure you get plenty of rest and drink fluids. Avoid drinking alcohol as it can make your headache worse, and it reduces the effect of Melatonin on sleep.

If these methods don’t work, ask a pharmacist to recommend a painkiller. Speak to your doctor if your headaches last longer than a week or are very severe.

Back pain or joint pain

Back and joint pain can be managed by resting and taking painkillers. See your doctor if the pain does not resolve in a few days or is severe.

Uncommon side effects

Research Trusted source electronic Medicines Compendium (eMC) Government Source UK Government Medicine Info Site Go to source suggests that uncommon side effects occur in ≥1 in 1000 patients. These may include:

Uncommon side effects
  • mood changes (irritability, nervousness, anxiety)
  • restlessness
  • abnormal dreams or nightmares
  • dizziness
  • dry mouth
  • nausea
  • dry or itchy skin, or a rash

Mood changes

If you experience mood changes and these bother you, make sure to tell your doctor. Rarely, Melatonin can cause a depressed mood. If this affects you, tell your doctor immediately.

Abnormal dreams or nightmares

Studies Trusted source PubMed Government Source Database of Biomedical Research Go to source show that taking Melatonin can increase the time spent in rapid eye movement (REM) sleep. The brain is highly active during REM sleep as it is the stage of sleep associated with dreaming and memory. This may be why taking Melatonin can result in abnormal dreams or nightmares.

If these symptoms bother you, speak to your doctor about changing your dose or finding alternatives.


To avoid feeling nauseous, ensure you are taking the tablets after a meal. Try to stick to simple meals and avoid eating rich or spicy food. Make sure to eat and drink slowly and have smaller meals more frequently rather than large meals.

You should also discuss the timing of your medicine and meals with a doctor.

Image of a nauseous woman covering her mouth

Dry mouth

If you experience a dry mouth, frequently sip water throughout the day. Also, try chewing sugar-free gum or sucking sugar-free sweets or lozenges.

Dry or itchy skin

If your skin becomes dry or itchy, apply a gentle moisturiser often. Other methods to combat dry skin include:

  • Limiting your shower time to 5 or 10 minutes
  • Blotting your skin dry with a towel
  • Use warm rather than hot water

If your skin does not improve or gets worse, talk to your doctor.

Serious side effects of Melatonin

Serious side effects are rare and happen to less than 1 in 1,000 people Trusted source electronic Medicines Compendium (eMC) Government Source UK Government Medicine Info Site Go to source . These may include:

  • Depressed mood
  • Blurred vision
  • Ulcers on the tongue
  • Vertigo
  • Abdominal pain

If you experience any of these side effects, seek immediate medical attention.

These are not all the side effects of Melatonin. For a full list, see the patient information leaflet included with your order.

How long do Melatonin side effects last?

Most side effects from Melatonin are typically short-term. Usually, side effects start soon after you take a tablet, and should resolve by themselves within several hours to a few days.

The duration of side effects depends on how you react to the medication. For adults, side effects from this medicine are usually uncommon and mild.

Side effects of Melatonin tend to occur with higher doses or extended-release formulations. These should disappear when you stop taking the medication.

Are there any long-term side effects of Melatonin?

According to research Trusted source National Center for Biotechnology Information (NCBI) Government Source Biomedical Research and Literature Go to source , taking Melatonin over a long period does not cause more long-term negative effects than taking a placebo. This is especially true when it is taken at a lower dosage.

However, more research into the long-term effects is needed.

Are there any side effects of Melatonin in kids?

The side effects of Melatonin in children are generally the same as in adults. Studies Trusted source The Lancet Peer-reviewed Journals Global Health Go to source show that children who use Melatonin are likely to experience non-serious adverse events, including headache, nausea, fatigue/drowsiness, dizziness, vomiting, and mood changes.

Image of a parent giving a child medicine

Can you overdose on Melatonin?

Yes, an overdose can occur if you take too much Melatonin. This can cause problems such as feeling very sleepy, having stomach issues, and getting headaches. Always stick to the recommended dose that has been prescribed for you.

When should I speak to a healthcare professional?

If you have been taking Melatonin tablets and are concerned that you are experiencing an adverse reaction to melatonin, you should report it to your doctor.

You may need to stop the treatment or reduce your dose, but it is best to talk to your doctor before doing so.

Medically reviewed by Dr. Caroline Fontana Written by our editorial team Last reviewed 28-06-2024
  • Select

  • Fill out a short
    medical form

  • Doctor issues

  • Medication sent
    from pharmacy