What are the contraindications to melatonin (N-acetyl-5-methoxytryptamine)?

From the Guidelines

Melatonin should be avoided in individuals with autoimmune disorders, bleeding disorders, seizure disorders, pregnant and breastfeeding women, and those with hormone-sensitive conditions, as well as used cautiously in people with depression, diabetes, or high blood pressure, due to potential adverse effects and interactions with other medications. The use of melatonin is contraindicated in several specific situations, including:

• Autoimmune disorders, such as rheumatoid arthritis, lupus, or multiple sclerosis, as it may worsen immune system activity 1
• Bleeding disorders or taking blood thinners like warfarin, due to potential increased bleeding risk
• Seizure disorders, as it may increase seizure frequency
• Pregnant and breastfeeding women, due to insufficient safety data
• Hormone-sensitive conditions, such as breast cancer, uterine cancer, or endometriosis, as it may influence hormone activity Additionally, people with depression, diabetes, or high blood pressure should use melatonin cautiously, as it may worsen these conditions 1. Melatonin can also interact with various medications, including immunosuppressants, anticoagulants, anticonvulsants, diabetes medications, and birth control pills, potentially reducing their effectiveness or increasing side effects 1. It is essential to consider these contraindications and potential interactions when prescribing or recommending melatonin, and to prioritize the patient's safety and well-being above all else. Some key points to consider when evaluating the use of melatonin include:
• The potential for adverse effects, such as increased bleeding risk or worsening of autoimmune disorders
• The potential for interactions with other medications, such as immunosuppressants or anticoagulants
• The lack of sufficient safety data in pregnant and breastfeeding women
• The need for cautious use in people with depression, diabetes, or high blood pressure
• The importance of monitoring patients for potential adverse effects and adjusting treatment as needed.

From the Research

Contraindications to Melatonin

• There are limited studies that provide clear contraindications to melatonin, but some populations may be at risk, including:
  • Patients with epilepsy, as melatonin may affect seizure control 2
  • Pre-adolescent children, due to concerns over potential adverse events 3
  • Patients with asthma, as melatonin may have unknown effects on this population 3
• Melatonin is generally considered safe and well-tolerated, with few adverse events reported in clinical trials 3, 4
• However, more research is needed to fully understand the potential risks and benefits of melatonin in various populations, particularly in the long-term 3, 5, 6
• Some studies suggest that melatonin may have therapeutic effects in neurological diseases, such as Alzheimer's disease, Parkinson's disease, and epilepsy, but more clinical trials are needed to confirm these findings 5, 6