Reviewed against FDA prescribing information

GLP-1 drug interactions

Every GLP-1 (Wegovy, Zepbound, Ozempic, Mounjaro, Foundayo) reviewed against 17 commonly co-prescribed medications. Click any row for the per-GLP-1 severity, mechanism, and clinical guidance.

GLP-1 + Insulin
Hypoglycemia risk — your insulin dose typically needs to come down 10-20% when starting any GLP-1.
Major
GLP-1 + Sulfonylureas
Hypoglycemia is the central concern — most prescribers reduce the sulfonylurea dose by half or stop it.
Major
GLP-1 + Oral contraceptives
Tirzepatide users: add a barrier method for 4 weeks after starting and after each dose increase. Semaglutide users: no contraceptive interaction documented.
Major
GLP-1 + Opioid analgesics
Aggressive bowel regimen is required. Consider non-opioid alternatives where clinically possible.
Major
GLP-1 + Warfarin
Check INR more frequently for the first 6-8 weeks on a GLP-1.
Moderate
GLP-1 + Levothyroxine
Take levothyroxine at least 60 minutes before any GLP-1 dose. Recheck TSH at 6-8 weeks after starting a GLP-1.
Moderate
GLP-1 + Alcohol
You will probably feel alcohol much faster on a GLP-1 — start lower than your pre-treatment baseline.
Monitor
GLP-1 + Berberine
No dangerous direct interaction, but berberine adds its own glucose-lowering effect — watch for hypoglycemia if you also take insulin or a sulfonylurea.
Monitor
GLP-1 + Antibiotics
You can take a short antibiotic course on a GLP-1 — but expect amplified GI upset, and stay hydrated to protect kidney function.
Monitor
GLP-1 + NSAIDs
Reasonable as-needed. Avoid daily NSAIDs in the first 8 weeks of a GLP-1 if possible.
Minor
GLP-1 + Metformin
Metformin + a GLP-1 is the most-prescribed combo in T2D care. Safe and synergistic.
No documented interaction
GLP-1 + Statins
Continue your statin as prescribed — no adjustment needed when starting a GLP-1.
No documented interaction
GLP-1 + SSRIs
Continue your SSRI. No dose change needed.
No documented interaction
GLP-1 + Caffeine
Safe to drink coffee on a GLP-1 — but caffeine on a near-empty, slow-emptying stomach can worsen nausea and reflux, especially in the first weeks.
No documented interaction
GLP-1 + Magnesium
Magnesium is commonly used to ease GLP-1 constipation and cramps — no dangerous interaction, just space it from other oral meds.
No documented interaction
GLP-1 + Creatine
Creatine is one of the most useful supplements to take with a GLP-1 — it helps preserve muscle during weight loss, with no interaction concern.
No documented interaction
GLP-1 + Vitamin B12
No interaction with your GLP-1 — but if you also take metformin, B12 monitoring is worth asking your prescriber about.
No documented interaction

This is educational content, not a clinical decision-support tool. Always discuss new and existing medications with the prescriber managing your GLP-1. Acute symptoms (severe abdominal pain, persistent vomiting, signs of pancreatitis) warrant immediate medical attention regardless of suspected drug interactions.