Melatonin and Autism Ranking:

Risks and Safety

Hazards

According to the BNF website, accessed on 22 August 2017, melatonin has few side effects but these may include the following: 

- Uncommon

Abdominal pain; abnormal dreams; anxiety; chest pain; dizziness; dry mouth; dry skin; dyspepsia; glycosuria; headache; hypertension; irritability; malaise; mouth ulceration; nausea; nervousness; proteinuria; pruritus; rash; restlessness; weight gain.

- Rare

Aggression; angina; arthritis; electrolyte disturbances; flatulence; gastritis; haematuria; halitosis; hot flushes; hypertriglyceridaemia; impaired memory; increased libido; lacrimation; leucopenia; mood changes; muscle spasm; nail disorder; palpitation; paraesthesia; polyuria; priapism; prostatitis; restless legs syndrome; salivation; syncope; thirst; thrombocytopenia; visual disturbances; vomiting

Contraindications

There are some contraindications (something which makes a particular treatment or procedure potentially inadvisable) for melatonin. 

For example, according to the BNF website, accessed on 22 August 2017, melatonin may be contraindicated for individuals with autoimmune disease.  The website also recommends that melatonin should be avoided in pregnancy and during breast feeding or in people with hepatic impairment. It also advises caution in people with renal impairment.

Melatonin may interact with a number of other medications, particularly cimetidine, fluvoxamine and oestrogens.

If you have concerns about melatonin you should seek advice from a responsible professional such as a GP. 

Notes

Angina (chest pain); autoimmune disease (condition in which the body’s immune system attacks itself); cimetidine (medicine used to treat ulcers and other conditions); dyspepsia (indigestion); electrolyte (nutrient); fluvoxamine (type of antidepressant); gastritis (inflammation of stomach lining); glycosuria (excretion of glucose in urine); haematuria (red blood cells in urine); halitosis (bad breath); hepatic (relating to the liver); hypertension (high blood pressure); hypertriglyceridaemia (fatty molecules in the blood); lacrimation (flow of tears); leucopenia (reduction of white blood cells); palpitation (abnormal heartbeat); paraesthesia (‘pins and needles’); polyuria (excessive production of urine); priapism (persistent and painful erection); prostatitis (inflammation of the prostate gland); proteinuria (protein in the urine); pruritus (itch); renal (relating to the kidneys); syncope (fainting); thrombocytopenia (abnormally low levels of red blood platelets).

Updated

16 Jun 2022

Last Review

01 Nov 2017

Next Review

01 Apr 2024