Melatonin: Uses, dosages, side effects

The article is professionally consulted by Master, Doctor Bui Ngoc Phuong Hoa - General Internal Medicine - Department of Medical Examination & Internal Medicine - Vinmec Danang International General Hospital

Melatonin is often prescribed to treat sleep disorders, such as insomnia and jet lag. Unlike other sleeping pills, users will not be dependent on Melatonin.

Melatonin is a hormone produced by the pineal gland, a pea-sized gland located in the center of the brain. Melatonin has the effect of causing drowsiness, so it is often used in regulating sleep, supporting insomnia and circadian rhythms, but it is not a sleeping pill.
Normally, your body makes more Melatonin at night, usually starting to increase in the evening when the sun goes down and gradually decreasing in the morning when the sun rises. In the human body, this hormone decreases with age. The older you get, the less this hormone is secreted.

Use Melatonin for insomnia, trouble sleeping and not sleeping well. Your sleep schedule has changed (due to the nature of your job, having to stay awake during your regular bedtime and sleep during your regular waking hours). This makes it difficult for you to fall asleep during your day sleep Insomnia due to time zone difference when traveling between countries with different time zones (Jet lag). Doctors are also studying to see if Melatonin could be an indication for:
Alzheimer's Disease Amyotrophic lateral sclerosis High blood pressure at night Sleep problems in children with a spectrum disorder autism

For adults
For disorders affecting sleep and wakefulness: 0.5 mg to 5 mg Melatonin orally daily at bedtime for up to 6 years in the blind. For delayed sleep phase disorder (DSPD): 0.3 to 5 mg of melatonin daily for up to 9 months. For sleep disturbances caused by blood pressure medications: 2.5 mg of melatonin orally daily for up to 4 weeks. For endometriosis: 10 mg of melatonin orally daily for 8 weeks. For high blood pressure: 2-3 mg of Melatonin for 4 weeks. For adult insomnia:
For primary insomnia: 2 mg to 3 mg Melatonin at bedtime for up to 29 weeks For secondary insomnia: 2-12 mg in up to 4 weeks. For Jet lag: 0.5-8 mg Melatonin at bedtime at destination, continue for 2 to 5 days. To reduce preoperative anxiety: 3-10 mg Melatonin 60-90 minutes before surgery. For painful symptoms affecting the jaw joint and muscles (temporomandibular disorder or TMD): 5 mg Melatonin at bedtime for 4 weeks. For low blood platelet levels caused by chemotherapy for cancer: 20-40 mg of melatonin daily from the start of treatment up to 7 days before starting a new cycle of chemotherapy. For Children
For disorders affecting sleep and wakefulness: 0.5-4 mg of Melatonin daily for up to 6 years in blind children. For delayed sleep disorder syndrome (DSPD): 1-6 mg of melatonin at bedtime up to one month. For pediatric insomnia:
For primary insomnia, 5 mg or 0.05-0.15 mg/kg body weight for 4 weeks. For secondary insomnia: 6-9 mg of melatonin orally at bedtime for 4 weeks. To reduce preoperative anxiety: 0.05-0.5 mg/kg body weight.

Melatonin used orally in appropriate doses is considered safe.
Melatonin side effects can cause such as:
Headache Dizziness Nausea Drowsiness Melatonin side effects are less common but can occur: persistent feeling of depression, mild tremors, mild anxiety, pain abdominal cramps, irritability, decreased alertness, confusion or disorientation, and low blood pressure.
Because Melatonin can cause daytime drowsiness, do not drive or use machines within five hours of taking the medicine.
Do not use Melatonin if you have an autoimmune disease.
Drug Interactions
Anticoagulants and antiplatelet drugs, herbs and supplements by reducing the ability of the blood to clot lead to an increased risk of bleeding. Melatonin may inhibit the effects of anticonvulsants in children with neurological deficits. Melatonin can increase blood pressure in people taking blood pressure medications. Because melatonin can affect blood sugar levels, if you take diabetes medication, use it carefully as directed by your doctor. Using birth control pills with melatonin may increase the effects and side effects of melatonin. Fluvoxamine (Luvox): This selective serotonin reuptake inhibitor can increase melatonin levels, causing excessive drowsiness. Melatonin may stimulate immune function and interfere with immunosuppressive therapy. Drugs that lower the seizure threshold. Taking Melatonin with these medicines may increase the risk of seizures.

References: Mayoclinic.org, Webmd.com