What's happening
Melatonin may have mild anticoagulant effects. Use caution if on blood thinners.
Recommendation
Inform doctor if taking both; monitor for bleeding.
Timing
Monitor for increased bleeding
Sources
- — Journal of Pineal Research
blood thinners and melatonin
Melatonin may affect blood clotting
Frequently Asked Questions
Can I take blood thinners and melatonin together?
Melatonin may affect blood clotting. Inform doctor if taking both; monitor for bleeding.
How should I time blood thinners and melatonin?
Monitor for increased bleeding
Is this interaction dangerous?
This interaction is rated “Caution” by Formulate. Melatonin may have mild anticoagulant effects. Use caution if on blood thinners.
Learn more about each substance
Cited research
Studies from our registry that mention blood thinners or melatonin. Each links to the primary source and the other Formulate pages citing it.
Mentions blood thinners · 2025
Impact of Ginkgo biloba drug interactions on bleeding risk and coagulation profiles
Primary literature · Observational study
Ginkgo + aspirin: bleeding risk OR 1.12 (95% CI 1.07-1.18, p<0.001); abnormal coagulation OR 1.48 (95% CI 1.32-1.66, p<0.001). Ginkgo + clopidogrel: bleeding risk OR 1.10 (95% CI 1.05-1.15, p<0.001); abnormal coagulation OR 1.58 (95% CI 1.40-1.77, p<0.001). Ginkgo + warfarin: NO statistically significant correlation with bleeding or coagulation.
Mentions melatonin · 2013
Meta-analysis: melatonin for the treatment of primary sleep disorders
Ferracioli-Oda E, Qawasmi A, Bloch MH · PLOS ONE
Meta-analysis of 19 RCTs (n=1,683) found melatonin reduced sleep-onset latency by ~7 minutes, increased total sleep time by ~8 minutes, and improved overall sleep quality — small but consistent effect across populations.
Mentions melatonin · 2012
The effect of magnesium supplementation on primary insomnia in elderly: a double-blind placebo-controlled clinical trial
Abbasi B, Kimiagar M, Sadeghniiat K, et al. · Journal of Research in Medical Sciences
8-week RCT in elderly with insomnia: 500mg/day magnesium significantly improved subjective insomnia score, sleep efficiency, sleep onset latency, and serum melatonin concentration.
Mentions melatonin · 2007
Efficacy of prolonged release melatonin in insomnia patients aged 55–80 years: quality of sleep and next-day alertness outcomes
Wade AG, Ford I, Crawford G, et al. · Current Medical Research and Opinion
3-week RCT in older insomnia patients (n=354) found prolonged-release melatonin 2mg improved sleep quality and morning alertness, supporting lower doses (1–3mg) over the often-oversold 5–10mg.
Other interactions to know
More interactions involving blood thinners or melatonin
- Dangernattokinase+blood thinners
Nattokinase has potent blood-thinning properties
- Warningblood thinners+ginkgo biloba
Ginkgo may modestly increase bleeding risk with warfarin, aspirin, or clopidogrel. Evidence is mixed but precaution is warranted.
- Cautiondiphenhydramine+melatonin
Both cause sedation - enhanced drowsiness
- Cautionmelatonin+ssri
Melatonin may enhance SSRI side effects
- Synergymelatonin+magnesium
Complementary sleep support
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Medical disclaimer. This page is for educational purposes only and does not replace advice from a qualified healthcare provider.
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