MODERATE — Monitor Closely
🟡 USE CAUTION — Melatonin and Warfarin may interact. Talk to your doctor before combining.
Evidence level: STRONG
Melatonin may slightly increase warfarin's blood-thinning effect. Monitor INR more closely.
Melatonin may have anticoagulant effects, potentially increasing INR with warfarin.
When taking Melatonin with Warfarin, monitor for unusual bruising or bleeding. Culinary amounts of Warfarin are generally safe; supplemental doses carry more risk. Inform your doctor about this combination.
High caution required. Fish oil, vitamin E, and nattokinase all have blood-thinning properties that can amplify Warfarin. CoQ10 and vitamin K can REDUCE warfarin effectiveness. Take at their normal times but inform your prescriber about ALL supplements. Request INR monitoring if starting or stopping any supplement while on an anticoagulant.
Higher risk with: older age (65+), history of GI bleeding, concurrent use of multiple blood-thinning agents, liver disease, heavy alcohol use, recent surgery.
Watch for unusual bruising, bleeding gums, nosebleeds, blood in urine or stool, prolonged bleeding from cuts. Report any of these to your doctor immediately.
Mention this combination at your next appointment. Ask: "Should I adjust timing or doses of Melatonin and Warfarin?" Your doctor may want to monitor specific lab values.
Blood thinners have narrow safety margins. Instead of Melatonin, consider safer options: CoQ10 (with INR monitoring), vitamin D3, or probiotics — these have minimal anticoagulant interactions. Always inform your anticoagulation clinic about any supplements.
Melatonin may slightly increase warfarin's blood-thinning effect. Monitor INR more closely.
High caution required. Fish oil, vitamin E, and nattokinase all have blood-thinning properties that can amplify Warfarin. CoQ10 and vitamin K can REDUCE warfarin effectiveness. Take at their normal times but inform your prescriber about ALL supplements. Request INR monitoring if starting or stopping any supplement while on an anticoagulant.
Watch for unusual bruising, bleeding gums, nosebleeds, blood in urine or stool, prolonged bleeding from cuts. Report any of these to your doctor immediately.
Blood thinners have narrow safety margins. Instead of Melatonin, consider safer options: CoQ10 (with INR monitoring), vitamin D3, or probiotics — these have minimal anticoagulant interactions. Always inform your anticoagulation clinic about any supplements.
Mention this combination at your next appointment. Ask: "Should I adjust timing or doses of Melatonin and Warfarin?" Your doctor may want to monitor specific lab values.
Or browse the full interaction database (121,000+ pairs).