Adverse effects of melatonin supplements analyzed

Ninety reports of adverse effects were analyzed by Anses in individuals who consumed dietary supplements containing melatonin. The reported effects include headaches, dizziness, nightmares, tremors, sleepiness, irritability, migraines, nausea, vomiting, and abdominal pain.

High-risk groups identified

Anses has identified certain populations for which the consumption of dietary supplements containing melatonin is strongly discouraged or should be completely avoided. This includes pregnant and breastfeeding women, children and adolescents, as well as people suffering from inflammatory or autoimmune diseases.

Safety concerns for specific activities

The agency also recommends great caution for anyone who needs to perform activities requiring sustained vigilance, as the sedative effects of melatonin can impair concentration or reflexes. These recommendations are based on a retrospective analysis of the reports received and a review of the available scientific literature.

Additional caution for specific health conditions

Beyond these populations, other situations require consulting a doctor before taking melatonin. This is the case for people with epilepsy, asthma, or those suffering from mood, behavior, or personality disorders. Melatonin can interact with other substances, and its properties on the immune system, blood vessels, or inflammation can affect the effectiveness or tolerance of certain medications.

Different regulations for melatonin products

In France, there are several forms of use of melatonin: medications, magistral preparations, and dietary supplements. However, these statuses are not equivalent. Dietary supplements, sold freely, are subject to a different regulation than melatonin-based medications, which are prescribed by healthcare professionals for specific medical indications and at controlled dosages.

Recommendations for cautious use

Anses has formulated recommendations for three groups: consumers, manufacturers, and healthcare professionals. The guiding principle is to prefer a temporary use of melatonin rather than prolonged consumption, due to insufficient data on its long-term effects.

Broader effects of melatonin

Anses has emphasized that melatonin, regardless of its form, remains an active substance with effects beyond sleep regulation, including on mood, the immune system, the regulation of body temperature, and even intestinal motility. It also has vasodilating, vasoconstricting, and pro-inflammatory properties. These effects highlight the need for caution in its use.