The short answer
Check INR more frequently for the first 6-8 weeks on a GLP-1.
Use with cautionGenerally OK with monitoring
Why it matters
GLP-1 delays gastric emptying, which can alter warfarin absorption. Reported INR shifts in both directions; no single predictable change.
What to do
INR check at 1, 2, 4, and 8 weeks after starting any GLP-1. Adjust warfarin dose only after a confirmed sustained shift. Once on GLP-1 maintenance for 3 months, INR stabilizes for most patients.
Ask your prescriber
“I take Warfarin. Is Ozempic safe with it, and what should we monitor?”
How Warfarin and Ozempic interact
GLP-1 delays gastric emptying, which can alter warfarin absorption. Reported INR shifts in both directions; no single predictable change.
What to do
INR check at 1, 2, 4, and 8 weeks after starting any GLP-1. Adjust warfarin dose only after a confirmed sustained shift. Once on GLP-1 maintenance for 3 months, INR stabilizes for most patients.
Before you start Ozempic
A licensed prescriber reviews your full medication and supplement list before prescribing a GLP-1. If you take Warfarin, mention it at your consultation.
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Same question, other GLP-1s
Other things people check with Ozempic
Full Warfarin interaction profile
See Warfarin reviewed against every GLP-1 on one page: Warfarin + GLP-1 interactions
Sources
Educational information, not medical advice. Always confirm interactions with your prescriber or pharmacist.
Common questions readers ask
- Can you drink alcohol on Wegovy?
- No hard contraindication, but alcohol tolerance often drops sharply on GLP-1. Many patients also report reduced desire for alcohol — likely a secondary effect of GLP-1 on the brain reward system. Full evidence-graded answer
- Can I take GLP-1 while pregnant?
- No. All FDA-approved GLP-1s carry a pregnancy contraindication. Stop GLP-1 at least 2 months before planned conception due to its long half-life. Full evidence-graded answer
- Is it safe to take GLP-1 long-term?
- Liraglutide has 15+ years of post-marketing data (Victoza approved 2010). Semaglutide has 8+ years (Ozempic approved 2017). No new class-wide safety signals have emerged in extended follow-up. Chronic use is the FDA-approved indication for both T2D and obesity. Full evidence-graded answer
- What happens if I miss a weekly GLP-1 dose?
- If within 5 days: take the missed dose as soon as you remember, then resume the regular schedule. More than 5 days late: skip it and inject your next scheduled dose. Never double up. Full evidence-graded answer
- Can GLP-1 cause thyroid cancer?
- The boxed warning is based on rodent studies showing medullary thyroid carcinoma (MTC) in mice and rats. No human cases have been attributed to GLP-1 use despite 10+ years post-approval surveillance. Full evidence-graded answer