Melatonin Re-Evaluated: New Research Challenges Long-Held Beliefs About the Sleep Hormone

Melatonin, a hormone long used to treat sleep disorders, is undergoing renewed scientific scrutiny, with recent studies questioning its efficacy and safety profile, according to research published in the Journal of Clinical Sleep Medicine and the U.S. Food and Drug Administration (FDA).

What Is Melatonin and How Is It Used?

Melatonin is a hormone produced by the pineal gland in the brain, regulating the sleep-wake cycle. It is widely available as an over-the-counter supplement, with approximately 2.1 million U.S. adults using it for sleep issues, per the 2021 National Survey on Drug Use and Health. However, new data suggest its benefits may be overstated, while risks—such as daytime drowsiness and interactions with medications—require closer examination.

Why Is Melatonin Being Re-Evaluated?

Recent meta-analyses, including one led by researchers at the University of Pennsylvania, found that melatonin’s effect on sleep onset latency (time to fall asleep) is minimal, reducing it by less than 10 minutes on average. “The data don’t support its use as a first-line treatment for chronic insomnia,” said Dr. Carl Johnson, a sleep specialist at the University of Michigan, in a 2023 review.

The FDA has also raised concerns about the consistency of over-the-counter melatonin products. A 2023 study in JAMA Internal Medicine found that some supplements contain up to 50% more or less melatonin than listed on labels, raising safety questions.

What Are the Alternatives to Melatonin?

Cognitive behavioral therapy for insomnia (CBT-I) remains the gold standard for treating sleep disorders, with long-term benefits and no risk of dependency. The American Academy of Sleep Medicine recommends CBT-I as the first intervention for most patients.

For short-term use, doctors may prescribe melatonin in low doses (0.5–1 mg) under medical supervision. However, the FDA has not approved it for long-term use, citing insufficient evidence of safety beyond two months.

What Does This Mean for Consumers?

Patients should consult healthcare providers before using melatonin, especially if taking blood thinners, antidepressants, or other medications. “It’s not a harmless supplement,” said Dr. Sarah Lin, a pharmacologist at the University of California, San Francisco, in a 2023 interview. “The risks may outweigh the benefits for some people.”

The FDA has also warned against giving melatonin to children, as its long-term effects on developing brains remain unstudied. “Parents should explore behavioral interventions first,” advised the agency in a 2023 safety alert.

What’s Next for Melatonin Research?

Researchers are now investigating melatonin’s role in conditions beyond sleep, such as neurodegenerative diseases and immune function. A 2023 trial in Nature Medicine suggested it may have antioxidant properties that could benefit Parkinson’s disease patients, but more studies are needed.

As the scientific community continues to refine its understanding, experts emphasize that melatonin should not replace evidence-based treatments. “It’s a tool, not a cure,” said Dr. Johnson. “Patients need to weigh the risks and benefits carefully.”