Updated over a week ago

Melatonin is available on prescription and is commonly used to help with sleep problems, such as insomnia or jet lag. It is often used as a short-term solution for adjusting sleep patterns or overcoming temporary sleep disruptions.

We'd like to give you some important information before you start taking it. It is also recommended to read the patient information leaflet to understand how the medication works, what to expect, and potential side effects and how to manage them.

Do understand how it works

Melatonin is a hormone naturally produced by the pineal gland in the brain. It plays a crucial role in regulating the sleep-wake cycle, also known as the circadian rhythm. The body typically releases melatonin in response to darkness, signalling the onset of sleep.

While melatonin can be effective for certain sleep-related issues, it's important to use it responsibly and follow the recommended dosage.

It's worth noting that melatonin is not a sedative and does not induce sleep like a sleeping pill would. Instead, it helps to regulate the sleep-wake cycle, making it easier to fall asleep and promoting a more restful sleep.

As with any supplement or medication, it's important to consult with a healthcare professional before starting melatonin, especially if you have any underlying health conditions or are taking other medications. They can provide personalised advice and guidance based on your specific situation.

Don't take if you

  • You have a sensitivity or allergy to the melatonin or to any of the excipients/ingredients listed below.

  • You are pregnant

  • You are breastfeeding

Do consult your doctor before starting Melatonin treatment if

  • If you have immunological diseases. Melatonin tablets are not recommended in patients with autoimmune disorder. Melatonin may affect the immune system, so individuals with autoimmune disorders should consult their healthcare provider before taking melatonin.

  • If you have epilepsy. Melatonin can potentially trigger seizures in individuals with epilepsy or seizure disorders. Therefore, it is important to consult a healthcare professional before using melatonin in these cases.

  • If you have diabetes. Melatonin taken in close proximity to ingestion of carbohydrate-rich meals may impair blood glucose control for several hours. Melatonin tablets should be taken at least 2 hours before and at least 2 hours after a meal; ideally at least 3 hours after meal by persons with significantly impaired glucose tolerance or diabetes.

  • If you take benzodiazepine-related hypnotics (medicines that help you sleep). Avoid use of melatonin with benzodiazepines. Melatonin may enhance the sedative effects of benzodiazepine-related hypnotics, e.g. zolpidem.

  • If you take medicines ciprofloxacin, norfloxacin and verapamil (CYP1A2 inhibitors) as they may increase the effects of melatonin considerably. Avoid Melatonin if you take Fluvoxamine.

  • If you take combined Hormonal Contraception. Contraceptives containing ethinylestradiol and gestagen can increase of the melatonin concentration. The dose of melatonin may need to be reduced.

  • If you take Hormone Replacement Therapy. HRT has been reported to delay some melatonin effects.

  • If you take carbamazepine, phenytoin, rifampicin, omeprazole or smoke cigarettes. These may decrease the effect of melatonin.

  • If you drink alcohol. Alcohol should not be used together with melatonin since it may reduce the effect of melatonin on sleep.

  • If you take nifedipine. Melatonin may reduce the blood pressure lowering effect of nifedipine.

  • If you take warfarin. Melatonin may have blood-thinning effects, so people with bleeding disorders or those taking anticoagulant medications should exercise caution and seek medical advice before using melatonin.

  • If you take Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) such as aspirin and ibuprofen, taken in the evening, may suppress your body's own melatonin levels. If possible, administration of NSAIDs should be avoided in the evening.

  • If you take beta-blockers. Beta-blockers may suppress your body's own melatonin production and should therefore be administered in the morning.

It is crucial to remember that this information is not exhaustive, and it's always best to consult with a healthcare professional who can assess your individual circumstances and provide appropriate advice regarding melatonin usage.

Do take correctly

  • Take 2mg tablet every day to help achieve normal sleep rhythm, 1-2 hours before bedtime and after food.

  • Swallow the tablets whole. Don’t chew them, as this can affect the way the medicine is absorbed. The best way to take the tablets is with a glass of water, to ensure that you swallow them easily.

  • Don’t take more than the recommended dose, and don’t take two doses at the same time. This can increase your risk of side effects (more on these below).

  • Take melatonin after you have eaten. Do not drink alcohol before, during or after taking melatonin because it reduces the effectiveness.

Do be aware of the possible serious side effects

If you experience any of the following serious (but uncommon) side effects, you should stop taking melatonin and seek urgent medical attention:

  • Chest pain

  • Loss of consciousness or fainting

  • Severe chest pain due to angina

  • Feeling your heartbeat

  • Depression

  • Visual impairment

  • Blurred vision

  • Disorientation

  • Vertigo (a feeling of dizziness or “spinning”)

  • Presence of red blood cells in the urine

  • Reduced number of white blood cells in the blood

  • Reduced blood platelets, which increases risk of bleeding or bruising

  • Psoriasis

Do be aware of the other possible side effects

If you experience any of the symptoms below that become serious or last longer than a few days stop taking melatonin and seek medical attention or contact our clinical team at [email protected]:

  • Headache

  • Sleepiness

  • Irritability, nervousness, restlessness, anxiety

  • Insomnia, abnormal dreams, nightmares

  • Migraine, dizziness, nausea

  • Lethargy (tiredness) and lack of energy, restlessness associated with increased activity

  • High blood pressure

  • Abdominal pain, indigestion, mouth ulceration, dry mouth

  • Changes in the composition of your blood which can cause yellowing of the skin and eyes

  • Inflammation of the skin, itching, rash, dry skin, night sweats

  • Pain in arms and legs

  • Excretion of glucose in the urine, excess proteins in the urine

  • Menopausal symptoms

  • Feeling of weakness, chest pain

  • Weight gain

  • Shingles

  • Reduced number of white blood cells in the blood

  • Reduced number of blood platelets

  • Low calcium or sodium levels in the blood

  • High level of blood fats

  • Altered mood, aggression, restlessness associated with increased activity, crying, stress
    symptoms, disorientation, early morning awakening, increased sex drive, depressed mood,

  • Fainting, memory impairment, disturbance in attention, dreamy state, restless legs syndrome,
    poor quality sleep, ‘pins and needles’ feeling, hallucinations

  • Visual impairment, blurred vision, watery eyes

  • Vertigo (a feeling of dizziness or “spinning”), dizziness when standing or sitting

  • Hot flushes

  • Acid reflux, gastrointestinal disorder, blistering in the mouth, tongue ulceration, stomach upset,
    vomiting, abnormal bowel sounds, wind, excess saliva production, bad breath, abdominal
    discomfort, inflammation of the stomach lining

  • Eczema, skin rash, hand dermatitis, itchy rash, psoriasis, nail disorder

  • Arthritis, muscle spasms, neck pain, night cramps

  • Passing large volumes of urine, urinating during the night, presence of red blood cells in the

  • Prolonged erection - that might be painful - without sexual stimulation, inflammation of the
    prostate gland

  • Tiredness, pain, thirst

  • Increased liver enzymes, abnormal blood electrolytes and abnormal laboratory tests

  • Hypersensitivity reaction, swelling of face, swelling of mouth, swelling of tongue

  • Abnormal milk secretion

  • Hallucinations (e.g. seeing, feeling or hearing things that don’t exist)

  • High blood glucose level

Driving and operating machinery

Melatonin may have a moderate effect on the ability to drive and use machines. If you do feel drowsy, do not drive or use machines.

What to do if you think you’ve taken more melatonin than you should

Drowsiness, headache, dizziness, and nausea are the most commonly reported signs and symptoms of overdose with oral melatonin.

It can take around 12 hours for these effects to subside, however if you have taken an overdose you must seek advice from a medical professional.

Fertility, pregnancy and lactation

There is insufficient data on the effects on fertility with melatonin. However, high doses of melatonin and use for longer periods than indicated may compromise fertility in humans.

Due to the lack of clinical data, melatonin is not recommended for use during pregnancy or in women of childbearing potential not using contraceptives.

Traces of Melatonin can be found in breastmilk therefore it is not recommended for breastfeeding women.

If you have any questions about taking melatonin please get in touch by emailing [email protected] or if you feel unwell and feel you need urgent medical attention please call NHS 111 or attend your nearest accident and emergency department.

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