The study and its comparison
Forty-six healthy young men were randomized in a single-blind study to one melatonin dose or placebo. Researchers measured selected coagulation factors one hour later. [1]
Factor VIII activity and fibrinogen were lower in the melatonin group. Factor VII activity and D-dimer did not significantly differ. The measured effects were limited to the tested laboratory endpoints and time point. [1]
What the finding establishes
A clotting-factor difference cannot quantify a person’s bleeding risk or establish prevention of thrombosis. The study also does not demonstrate safety when combined with an anticoagulant. Funding and conflicts were not established from the abstract. Clinical interaction decisions require more than this small acute experiment. [1]
A hypothetical distinction
Imagine two laboratory factors change while no bleeding events are studied. The clinical bleeding question remains open.
| Detail | Interpretation |
|---|---|
| Measured outcome | Keep the endpoint specific |
| Study preparation | Not every retail product |
| Remaining uncertainty | Not resolved by a mechanism |
Sources for this article
- Oral melatonin reduces blood coagulation activity: a placebo-controlled study in healthy young men.
Source consulted: 2026-09-19. This is a reference resource, not a claim that we conducted the studies or tested a product.