MADRID, January 21, 2026 — A surprising ally emerged during the height of the SARS-CoV-2 crisis: melatonin, the hormone best known for regulating sleep, dramatically reduced 90-day mortality rates in critically ill patients by nearly 40 percent, according to a new study. This finding suggests melatonin could be a powerful, readily available tool in combating severe viral illness.
Sleep Hormone Shows Promise in Critical Care
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The study revealed that high doses of melatonin lowered 90-day mortality from 36.1% to 20.8% in critically ill patients.
- Researchers at the San Carlos Clinical Hospital in Madrid found melatonin significantly improved outcomes for patients with severe COVID-19.
- High doses – up to 200 milligrams daily – were administered alongside conventional treatments.
- Melatonin not only fought the virus but also protected organs from systemic collapse, reducing hospital infections and complications.
- The findings suggest potential applications beyond COVID-19, including septic shock, cardiac arrest, and stroke.
The research, published in the Journal of Medical Virology, analyzed 335 patients battling for their lives in intensive care. Led by Miguel Sánchez, an expert in intensive care medicine, the team initially explored melatonin as a potential therapy and discovered a remarkable hormonal approach that could alter the course of multiple organ failure.
The treatment protocol involved alternating conventional care with periods supplemented by oral melatonin doses of up to 200 milligrams daily. Researchers meticulously ruled out improvements stemming from other medications, such as antivirals or corticosteroids, before confirming melatonin’s protective effects. The hormone didn’t just combat the virus; it shielded organs from widespread systemic failure.
Patients receiving melatonin experienced a notable decrease in hospital infections and ventilation-associated pneumonia. Furthermore, lung trauma, such as barotrauma, was reduced, leading to shorter hospital stays and quicker transitions off mechanical ventilation.
A New Frontier in Emergency Medicine
Dr. Sánchez emphasizes that melatonin’s antioxidant and neuroprotective properties open exciting possibilities for treating other critical conditions. The observed success suggests the compound could be crucial in managing septic shock, cardiac arrest, and even stroke, where free radical damage plays a devastating role.
The Madrid team is now planning a larger, multicenter, double-blind trial to solidify melatonin’s position as a first-line treatment. As the world prepares for future biological threats, this study underscores that effective solutions may already be within reach, waiting to be utilized correctly. Data from Europa Press contributed to this report.
