Clinical tool
Pick your GLP-1 and search for any common adjunct medication. Severity-coded — safe, monitor, caution, avoid — with the underlying rationale.
Metformin
antidiabetic
Common combo. No pharmacokinetic interaction; complementary mechanisms (metformin → insulin sensitivity, GLP-1 → secretion + satiety).
Insulin
aka Lantus, Humalog, Novolog, Tresiba
antidiabetic
Combined GLP-1 + insulin substantially raises hypoglycemia risk. Prescribers typically reduce insulin 10-20% when starting a GLP-1.
Sulfonylureas
aka Glipizide, Glyburide, Glimepiride
antidiabetic
Same hypoglycemia concern as insulin. Most clinicians taper or stop sulfonylureas after the GLP-1 reaches a clinically active dose.
Statins
aka Atorvastatin, Rosuvastatin, Simvastatin
lipid-lowering
No clinically significant interaction. GLP-1 slows gastric emptying but statin absorption is not meaningfully affected.
Warfarin
anticoagulant
Slowed gastric emptying can shift warfarin absorption. Check INR more frequently after starting a GLP-1 or escalating dose.
Levothyroxine
thyroid
Take 30-60 min before food or GLP-1 dose. Some patients see TSH drift after months — re-check 6-8 weeks after starting.
SSRIs
aka Lexapro, Zoloft, Prozac
antidepressant
No direct interaction. Some patients report nausea synergy; tolerance usually develops within 2-3 weeks.
Phentermine
anti-obesity
Off-label combo with limited safety data. Possible additive cardiovascular load (HR, BP). Not recommended outside obesity-medicine specialist supervision.
Alcohol
social
GLP-1 lowers tolerance. Hangovers + nausea are more pronounced; multiple-drink sessions can worsen dehydration risk.
Opioids
aka Oxycodone, Hydrocodone, Codeine
pain
Both slow gut motility — constipation and ileus risk rises. Aggressive bowel regimen if combining.
Educational only. Confirm any combination with your prescriber and the dispensing pharmacist — many interactions depend on dose and timing.