Summary

Melatonin refers to a stress hormone naturally secreted by the human body’s pineal gland, a small endocrine gland located in the centre of the vertebrate brain [1][2].

Benefit and Effects

Healthy Sleep

Among 1,683 subjects, melatonin decreased latent onset of sleep, improved overall sleep quality, and prolonged total sleeping time. [6].

Research has shown that normal nocturnal increase in melatonin production is reduced in patients with Autism Spectrum Disorder (ASD), resulting in frequent sleep disturbances [7].

Uterine Health and Pelvic Pain Relief

Melatonin improved overall sleep quality in women with endometriosis-associated chronic pelvic pain. Further, melatonin was found to have a managing effect on the secretion of brain-derived neurotrophic factor (BNDF) [12][13].

Deficient melatonin levels may be reliable indicators of endometrial cancer [15]. Its essential functions in the human ovary indicate that it may serve as a therapeutic agent for conditions such as polycystic ovary syndrome (PCOS) and premature ovarian failure, as well as endometriosis [14].

Cardiovascular Health

Melatonin has been clinically proven to yield a direct impact on cardiovascular health. [16]. A 2010 study using 30 patients with metabolic syndrome revealed that systolic and diastolic blood pressure were significantly decreased while antioxidative enzymes were significantly increased after two months of consistent nightly melatonin administration [19].

How it works

Melatonin is a sleep regulator as opposed to a sleep instigator. [21]. Melatonin supplements primarily come in pill or chewable tablet form [5].

Melatonin duration

Melatonin can remain in the body for up to twelve hours, in accordance with the body’s natural circadian rhythms. [5].

Dosage

Available melatonin dosage for adults ranges from 0.3 mg to 10 mg. Max dose of melatonin can reach 20 mg [23]. Individuals with chronic sleep conditions should consult a physician regarding the appropriate dosage for them.

Melatonin Overdose

Excessive use may cause grogginess during the day and insomnia at night, nausea, dizziness, irritability or unstable mood, gastrointestinal upset, and/or joint pain. Individuals have also reported “melatonin dreams” after taking an excess of the supplement [25]. However, no cases of severe or life-threatening symptoms have been reported as a result of excess melatonin ingestion [28].

Melatonin for Children

To date, no studies have been conclusive enough to verify the safety and efficacy of regular melatonin supplementation in children. A safe dose of melatonin for adults (1 mg or higher) may induce a seizure in a young child [28].

Melatonin for Pets

The appropriate melatonin dosage for dogs is entirely dependent on the individual canine’s medication sensitivity, weight, and size, and should be determined only at the discretion of a veterinarian [30]

Contraindications

Individuals with psychiatric or seizure disorders, bleeding or coagulation disorders, diabetes, and/or a history of medical transplant should avoid melatonin.[31].

Melatonin and alcohol should be avoided together [32]. Side effects may include elevated heart rate, inability to concentrate, flushing, swelling in the ankles or feet, and/or fainting [33].

Melatonin and birth control are also contraindicated; melatonin may interfere with the regulatory hormonal mechanisms of oral contraceptives [34]. Pregnant or breastfeeding women should not take melatonin [5].

Side Effects

Side effects include headache, gastrointestinal cramps or upset, transient depression, anxiety or irritability, and/or dizziness [5].