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Melatonin 1 mg/1 ml Oral solution

Active Ingredient:
ATC code: 
N05CH01
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About Medicine
The Patient Information Leaflet (PIL) is the leaflet included in the pack with a medicine.
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Last updated on emc: 13 Feb 2026

Below is a text only representation of the Patient Information Leaflet (ePIL).

The text only version may be available in large print, Braille or audio CD. For further information call emc accessibility on {phone} 0800 198 5000. The product code(s) for this leaflet is: PL 39307/0097.

Melatonin 1mg/ml Oral Solution

Package leaflet: Information for the user

Melatonin 1mg/ml Oral Solution

Read all of this leaflet carefully before you or your child start taking this medicine because it contains important information for you.
  • Keep this leaflet. You may need to read it again.
  • If you have any further questions, ask your doctor or pharmacist.
  • This medicine has been prescribed for you only. Do not pass it on to others. It may harm them, even if their signs of illness are the same as yours.
  • If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. See section 4.

The name of your medicine is Melatonin 1mg/ml Oral Solution but it will be referred to as 'Melatonin' throughout this leaflet.

What is in this leaflet

1. What Melatonin is and what it is used for
2. What you need to know before you take Melatonin
3. How to use Melatonin
4. Possible side effects
5. How to store Melatonin
6. Contents of the pack and other information

1. What Melatonin is and what it is used for

Melatonin oral solution contains the active substance melatonin, which is a hormone produced naturally by the body. This hormone helps regulate the body’s day and night rhythm.

Melatonin oral solution can be used for:

  • Short-term treatment of jet lag in adults. Jet lag refers to the symptoms caused by the time difference when travelling through several time zones.
  • Insomnia (sleeplessness) in children and adolescents (6 to 17 years old) with ADHD, where healthy sleeping routines have not worked well enough.
  • Treatment of delayed sleep wake phase disorder (DSWPD) (disruption of the body’s day and night rhythm) in children and adolescents (6 to 17 years old) and adults up to 25 years of age, where healthy sleeping routines have not worked well enough.
  • Sedation of children and adolescents (1 to 18 years old) who are having a medical procedure called an electroencephalogram (EEG) in hospital.

2. What you need to know before you take Melatonin
Do not take Melatonin
  • if you are allergic to melatonin or any of the other ingredients of this medicine (listed in section 6).

Warnings and precautions

Talk to your doctor or pharmacist before taking Melatonin

  • if you have epilepsy. Melatonin may increase seizure frequency in patients with epilepsy
  • if you have an autoimmune disease (where the body is ‘attacked’ by its own immune system)
  • if you have diabetes or impaired glucose tolerance, as this medicine may increase the level of glucose in your blood
  • if you suffer from significantly impaired liver function or kidney function
  • if you smoke. Smoking may reduce the effect of Melatonin as components of tobacco smoke can increase the breakdown of melatonin by the liver.

Care should be exercised when changing between different formulations/ products, as changing formulations may increase the risk of drowsiness.

Children and adolescents

Do not give this medicine to children under 6 years of age.

Other medicines and Melatonin

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines.

Some medicines may increase the effect of melatonin. These include:

  • Fluvoxamine (used for the treatment of depression and obsessive-compulsive disorder), as fluvoxamine may increase the effect of melatonin
  • Psoralens (used for the treatment of skin disorder e.g. psoriasis), as psoralens may increase the effect of melatonin
  • Cimetidine (used for the treatment of stomach problems such as ulcers), as cimetidine may increase the effect of melatonin
  • Oestrogens (used in contraceptives or hormone replacement preparations), as oestrogens may increase the effect of melatonin
  • Quinolones (used in the treatment of bacterial infections), as quinolones may increase the effect of melatonin

Some medicines may decrease the effect of melatonin. These include:

  • Rifampicin (used in the treatment of bacterial infections), as rifampicin may decrease the effect of melatonin
  • Carbamazepine (used in the treatment of epilepsy), as carbamazepine may decrease the effect of melatonin

Melatonin can increase the sedative effect of some medicines:

  • Benzodiazepines and non-benzodiazepine hypnotics (medicines used to induce sleep, e.g. midazolam, temazepam and zaleplon, zolpidem, zopiclone), as melatonin may enhance the sedative effect of such drugs, and may enhance certain side effects of zolpidem (morning sleepiness, nausea, confusion)

Melatonin may influence the effect of:

  • Warfarin (anticoagulants), as melatonin may influence the effect of the anticoagulant warfarin.

Melatonin with food, drink and alcohol
  • Food may alter the effectiveness of melatonin. Do not eat food 2 hours before or after taking melatonin.
  • As alcohol can impair sleep and potentially worsen certain symptoms of jet-lag (e.g. headache, morning fatigue, concentration) it is recommended that alcohol is not consumed while taking this medicine.

Pregnancy, breast-feeding and fertility

If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.

Pregnancy

Melatonin is not recommended if you are pregnant. Melatonin crosses the placenta and there is insufficient information on the risk this may pose to the unborn child. If you are woman of childbearing potential you have to use contraception.

Breast-feeding

Melatonin is not recommended if you are breast-feeding. Melatonin is excreted in human milk, and a risk to the sucking child cannot be excluded.

Fertility

Melatonin is not recommended in women and men planning to have a baby as there is insufficient information on the effects of melatonin on female and male fertility.

Driving and using machines

Melatonin may cause drowsiness and may decrease alertness for several hours after intake. Therefore, this medicine should not be taken prior to driving or using machines.

Melatonin contains

Propylene glycol (E1520): This medicinal product contains 174.25mg propylene glycol in each 5ml which is equivalent to 34.85mg/ml.

3. How to use Melatonin

Always use this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure.

Adults with jetlag:

The recommended dose for adults and elderly is 3ml (3mg) daily for a maximum of 5 days. When the effect of Melatonin is inadequate, 6ml (6mg) can be taken.

The first dose should be taken on arrival at destination at your usual bed-time. Intake on the following days should also be at your usual bed-time. The medicine should not be taken before 20:00 hr or after 04:00 hr.

Melatonin may be taken for a maximum of 16 treatment periods per year.

Insomnia (sleeplessness) in children and adolescents with ADHD:

In children and adolescents with ADHD, the recommended starting dose is 1 to 2 ml (1 to 2 mg), 30 to 60 minutes before bedtime. The dose can be increased up to a maximum of 5 ml (5 mg) per day depending on your response.

Delayed sleep wake phase disorder:

The recommended dose is:

1 to 5 ml (1 to 5 mg) per day, 1 to 2 hours before going to bed. The maximum daily dose is 5 ml (5 mg). Your doctor will likely start you at a low dose (1 to 2 mg) and adjust it depending on your response.

For both insomnia and DSWPD, you or your child should be monitored by your doctor at regular intervals (recommended at least every 6 months) to check that melatonin is still the right treatment for you/them.

Treatment should be interrupted once a year to see if it is still needed. For some patients, treatment can be continued past the usual age ranges if the doctor considers it appropriate.

Sedation:

Melatonin will be given 30 to 45 minutes before the start of the procedure. The dose will be determined by your doctor depending on your child’s weight. A ‘top-up’ dose may be given if sleep is not achieved 45 minutes after the first dose – this will usually be half the first dose. Only one melatonin assisted EEG should be performed per 24 hour period.

Method of administration

Swallow the solution with water or other liquid (e.g. milk, fruit juice). Food should not be consumed 2 hours before or 2 hours after intake of Melatonin.

Instructions for the use of syringe:

a) Open the bottle: press the cap and turn it anticlockwise (figure 1).

b) Separate the adaptor from the syringe (figure 2). Insert the adaptor into the bottle neck (figure 3). Ensure it is properly fixed. Take the syringe and put it in the adaptor opening (figure 4).

c) Turn the bottle upside down. Fill the syringe with a small amount of solution by pulling the piston down (figure 5A), then push the piston upwards in order to remove any possible bubble (figure 5B). Pull the piston down to the graduation mark corresponding to the quantity in millilitres (ml) prescribed by your doctor (figure 5C).

d) Turn the bottle the right way up (figure 6A). Remove the syringe from the adaptor (figure 6B).

e) Empty the contents of the syringe into the patient's mouth by pushing the piston to the bottom of the syringe (figure 7). The contents of the syringe should be emptied into the side cheek of the patient's mouth to avoid a choking hazard. Close the bottle with the plastic screw cap. Wash the syringe with water (figure 8).

If you take more Melatonin than you should

If you or your child have taken more Melatonin than recommended and you do not feel well, please contact your doctor, hospital or pharmacy.

The most common symptoms of overdose are drowsiness, headache, dizziness, and nausea.

If you forget to take Melatonin

If you forget to take a solution at bedtime and wake during the night you may take your next dose at the correct time.

Do not take a double dose to make up for a missed dose.

If you stop taking Melatonin

If you stop taking Melatonin, it will not have any harmful effects or withdrawal symptoms.

If you have any further questions on the use of this medicine, ask your doctor or pharmacist.

4. Possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.

Serious side effects

If you or your child experience any of the following serious side effects stop taking this medicine and contact your doctor immediately:

Uncommon: may affect up to 1 in 100 people

  • Chest pain

Rare: may affect up to 1 in 1,000 people

  • Reduced number of white blood cells in the blood
  • Reduced number blood platelets, which increases the risk of bleeding or bruising
  • Disorientation
  • Fainting
  • Visual impairment, including blurred vision
  • Feeling your heartbeat (‘pounding chest’)
  • Blood (red blood cells) in the urine

Not known: frequency cannot be estimated from available data

  • Hypersensitivity reaction, (allergy like reactions such as difficulty breathing, itching)
  • Swelling of deeper layers of skin (angioedema)
  • Swelling of face, mouth and/or tongue (oedema)

Non-serious side effects

If you experience any of the following non-serious side effects contact your doctor or pharmacist:

Common: may affect up to 1 in 10 people

  • Headache
  • Drowsiness

Uncommon: may affect up to 1 in 100 people

  • Irritability, nervousness, restlessness, abnormal dreams, anxiety
  • Night sweats
  • Lack of energy and enthusiasm
  • Migraine
  • Dizziness
  • High blood pressure
  • Abdominal pain, upper abdominal pain, indigestion, mouth ulceration, dry mouth, nausea
  • Skin disorders (dermatitis, pruritus, rash, dry skin)
  • Pain in arms and legs
  • Menopausal symptoms
  • Excretion of glucose in the urine, excess protein in the urine
  • Abnormal liver function tests
  • Feeling unwell
  • Weight increase

Rare: may affect up to 1 in 1,000 people

  • Shingles (herpes zoster)
  • High levels of certain fat molecules (triglycerides) in the blood
  • Altered mood, aggression, disorientation, increased sex drive, low mood, depression
  • Memory impairment, restless legs syndrome, ‘pins and needles’ sensation, disturbance in attention, poor quality sleep, tiredness (fatigue)
  • Watery eyes
  • Dizziness or spinning with changes in head position e.g. looking up or bending down (positional vertigo)
  • Skin disorders (skin redness, skin rashes, eczema, psoriasis), nail disorder, sudden feeling of heat (hot flushes)
  • Acid reflux, gastrointestinal disorder, blistering in the mouth, tongue ulceration, stomach upset, vomiting, wind, excess saliva, bad breath, inflammation of the stomach lining, abnormal bowel sounds, abdominal discomfort
  • Pain, arthritis, muscle spasms, neck pain, night cramps
  • Passing large volumes of urine, need to urinate at night
  • Prolonged erection that might be painful, inflammation of the prostate gland
  • Thirst
  • Increased liver enzymes, abnormal blood electrolytes, abnormal laboratory tests

Not known: frequency cannot be estimated from available data

  • High blood glucose level
  • Flow of milk from the breasts (also in men)

Reporting of side effects

If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects, you can help provide more information on the safety of this medicine.

5. How to store Melatonin
  • Keep this medicine out of the sight and reach of children.
  • Do not use this medicine after the expiry date which is stated on the carton and bottle label after ‘EXP’. The expiry date refers to the last day of that month.
  • Do not store above 30°C.
  • For 50ml: Discard 30 days after first opening.
  • For 100ml: Discard 60 days after first opening.
  • Do not use this medicine if you notice that the solution becomes discoloured or shows any signs of deterioration. Seek the advice of your pharmacist.
  • Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.

6. Contents of the pack and other information
What Melatonin contains

The active substance is melatonin.

Each ml of oral solution contains 1mg melatonin.

The other ingredients are propylene glycol (E1520), glycerol (E422) and orange flavour (containing propylene glycol (E1520)).

What Melatonin looks like and contents of the pack

Melatonin is a clear, colourless to pale yellow colour solution supplied in amber glass bottle with tamper evident, child resistant plastic cap. The pack also contains a 10ml oral syringe with 0.5ml graduation for measuring the dose and a syringe adaptor.

Melatonin is supplied in bottles containing 50ml or 100ml solution.

Marketing Authorisation Holder and Manufacturer:
Syri Limited
Unit 4
Bradfield Road
Ruislip
Middlesex
HA4 0NU
UK

Trading as:

SyriMed
Unit 4
Bradfield Road
Ruislip
Middlesex
HA4 0NU
UK

If this leaflet is hard to see or read, please call +44 (0) 208 515 3700 for help.

This leaflet was last revised in 12/2025.

NAT/VAR/II-001/RFI-II

SyriMed
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Address
Unit 4, Bradfield Road, Ruislip, Middlesex, HA4 0NU
Telephone
+44 (0)208 515 3700
Medical Information Direct Line
0330 1359 422
Medical Information e-mail
[email protected]
Customer Care direct line
+44 (0)208 515 3700
Stock Availability
+44 (0)208 515 3700