You’ll usually take melatonin for up to 13 weeks but some people may need it for longer.
Some people may get a headache, or feel tired, sick or irritable the day after taking melatonin.
Drinking alcohol or smoking while taking melatonin can stop it working as well as it should.
If you’re taking melatonin to help you sleep, do not take any herbal remedies which may affect sleep at the same time. This may make you very drowsy.
