GLP-1 Contraindications: Safety Checklist & Risk Assessment

The most useful safety checklist starts with the exact medicine. A labeled contraindication is different from a warning, a use that is not recommended, or a condition that needs monitoring. This US guide focuses on semaglutide and tirzepatide, with examples showing why rules cannot always be extended to every GLP-1 product.

Labeled Contraindications: When the Named Product Should Not Be Used

The Wegovy, Ozempic, Mounjaro and Zepbound labels list MTC/MEN 2 exclusions and serious hypersensitivity. Pregnancy and lactation have separate product-specific sections. Other agents differ: the Byetta label lists severe hypersensitivity and prior exenatide-induced immune-mediated thrombocytopenia, not the same thyroid exclusion. This distinction is not a recommendation to substitute Byetta for someone with MTC.

Personal History of Medullary Thyroid Carcinoma (MTC)

Family History of MTC or MEN 2 Assessment

A family history of MTC also excludes the named products; it does not require multiple affected relatives. MEN 2 in the patient is separately listed. A family history of MEN 2 warrants specialist assessment for the inherited syndrome and associated MTC history.

Genetic counseling may help clarify an uncertain diagnosis, but a negative genetic test does not erase a known family history of MTC. Do not treat testing or routine calcitonin screening as a workaround to a labeled exclusion.

Serious Allergic Reaction to the Product

A previous serious reaction to the active drug or an ingredient is another labeled contraindication. Difficulty breathing or swelling of the face, tongue or throat needs emergency care. Do not retry a product that caused a serious reaction without medical evaluation.

Pregnancy and Preconception Planning

Weight-loss treatment is not appropriate during pregnancy. For weight management, the Wegovy label and Zepbound label direct discontinuation when pregnancy is recognized. Contact the prescriber promptly to arrange the next steps. Animal findings indicate potential fetal harm; they do not establish the size of a human risk.

• For semaglutide used for weight management, stop at least two months before a planned pregnancy under the label guidance.
• Do not transfer that two-month instruction to tirzepatide as though it appears in its US label. Agree on a product-specific preconception plan before trying to conceive.
• Diabetes or liver-disease treatment requires an indication-specific assessment and a replacement-care plan. The current labels do not put every pregnancy situation in the same contraindication category. Do not abandon glucose management or stop insulin.
• For tirzepatide and oral hormonal contraception, follow the four-week protection rule below; moving the pill to a different time is not the label-recommended solution.

Breastfeeding: Formulation Matters

A blanket breastfeeding contraindication is inaccurate. The Wegovy label, section 8.2, advises against breastfeeding during tablet treatment because of the absorption enhancer SNAC. Its injection guidance instead calls for assessment of maternal need, breastfeeding benefits and potential infant effects.

The tirzepatide lactation data describe low or undetectable milk concentrations after a single dose, but do not establish effects on the infant or milk production. Those findings are useful, not proof of safety with repeated treatment. Discuss the exact formulation, infant age and maternal indication with the prescribing and pediatric clinicians.

Conditions Requiring Product-Specific Assessment and Monitoring

These topics are worth discussing, but they are not all formal “relative contraindications.” Some involve a label warning; others involve limited evidence or an opportunity for benefit. The distinction helps avoid both unnecessary exclusion and false reassurance.

Type 1 Diabetes

Semaglutide and tirzepatide are not substitutes for insulin and do not have an FDA-approved type 1 glucose-control indication. That is different from saying there is no supportive research or that obesity treatment is automatically prohibited in every person with type 1 diabetes.

A 2025 randomized crossover trial by Pasqua and colleagues studied semaglutide alongside automated insulin delivery: 28 adults were randomized and 24 completed the trial. Time in the target glucose range improved, but two episodes of euglycemic ketosis without acidosis occurred during semaglutide use. This is promising adjunct evidence, not an instruction to replace or independently reduce insulin. Specialist oversight and an individualized glucose/ketone plan matter.

Personal History of Acute Pancreatitis

Previous pancreatitis needs a discussion of its cause, recurrence history and alternatives. The Zepbound warning addresses observed acute pancreatitis; it does not establish a predictable recurrence risk for every patient with a previous episode. Neither an automatic exclusion nor a reassurance of no risk follows from that history alone.

Persistent or severe abdominal pain, sometimes spreading to the back and occurring with or without vomiting, needs prompt medical assessment. When pancreatitis is suspected, the label directs discontinuation and appropriate treatment. Severe symptoms warrant urgent care rather than waiting for the next routine appointment.

History of Gallbladder Disease or Gallstones

Gallbladder events have been reported during treatment. Weight loss can contribute, but it is not the only explanation. Discuss existing gallstones and previous attacks; these are not themselves listed as blanket contraindications in the named labels. New upper-abdominal pain, fever or jaundice needs assessment. The clinician decides whether imaging or other testing is appropriate.

Chronic Kidney Disease

Kidney disease does not create one class-wide dose rule. The Ozempic, Mounjaro and Zepbound labels do not require renal dose adjustment, including kidney failure or end-stage renal disease. An eGFR below 30 is not an automatic dose-reduction threshold for those products.

By contrast, Byetta is not recommended with creatinine clearance below 30 mL/min or end-stage renal disease. Creatinine clearance and eGFR are related but not interchangeable measures. Advanced disease or dialysis still merits individualized care, especially if vomiting, diarrhea or poor intake causes volume depletion. No renal adjustment does not mean no kidney monitoring.

Diabetic Retinopathy (Vision-Threatening)

Rapid improvement in glucose control can temporarily worsen diabetic retinopathy. The current Zepbound warning, section 5.8, calls for monitoring people with a history of retinopathy; semaglutide labeling also addresses this issue. Coordinate follow-up with the eye clinician, particularly with active disease, and promptly report changes in vision. Retinopathy is not automatically a class-wide contraindication.

Diabetic Nephropathy (Kidney Damage from Diabetes)

There is also evidence of benefit: Ozempic is indicated to reduce sustained eGFR decline, end-stage kidney disease and cardiovascular death in adults with type 2 diabetes and chronic kidney disease. This is a defined product and population, not a guarantee that every GLP-1 improves every kidney condition. Discuss kidney function, fluid balance and the other medicines in the treatment plan.

History of Other Thyroid Cancer (Non-MTC)

Papillary, follicular and anaplastic cancers should not be relabeled as MTC. They are not named as the same contraindication in the four labels above. The exact diagnosis, active treatment and nutritional needs still deserve discussion with the prescriber and oncology team; “not listed” is not a personalized clearance.

Personal or Family History of C-Cell Hyperplasia

Clarify the diagnosis with an endocrinologist rather than assigning a universal relative-contraindication label. What matters is whether it indicates MTC, MEN 2 or another relevant thyroid condition. Rodent findings do not prove that these drugs stimulate C-cell growth in humans. Known MTC history remains an exclusion for the named products.

Severe Gastroparesis (Severe Gastric Emptying Delay)

Wegovy, Mounjaro and Zepbound are not recommended in severe gastroparesis under their labels. This is delayed stomach emptying, not synonymous with a mechanical blockage. Tell the prescriber about a diagnosis or persistent symptoms before treatment; a general “use with monitoring” statement should not obscure the not-recommended wording.

Also tell the anesthesia or procedure team about GLP-1 treatment before surgery or deep sedation. The labels describe aspiration reports despite fasting. The care team should determine the plan; this guide does not impose a universal medication-holding interval.

History of Severe Nausea or Vomiting Disorders

Nausea and vomiting are common treatment effects, but their frequency varies by product, dose and trial population. A history of severe symptoms calls for an assessment of the cause and likely tolerability. Persistent vomiting or inability to keep fluids down needs prompt clinical advice.

Inflammatory Bowel Disease (IBD: Crohn’s or Ulcerative Colitis)

IBD is not listed as a contraindication in the four named labels. Emerging evidence is reassuring: Levine and colleagues’ 224-patient observational study found no significant increase in exacerbations in the year after GLP-1 initiation compared with the prior year, alongside weight reduction. This was not a randomized trial or proof of safety in every disease state. Coordinate treatment with the gastroenterology team, especially with active symptoms or poor intake.

High Risk for Dehydration

Vomiting, diarrhea or reduced intake can cause volume depletion and acute kidney injury. Agree on a fluid plan suited to your situation rather than aiming for a mandatory 100-plus ounces daily. Fluid needs during dialysis illustrate why a prescribed fluid restriction requires a different plan. Seek help for persistent fluid losses, very low urine output, fainting or inability to drink.

Significant Drug Interactions

Delayed stomach emptying can affect oral-drug absorption, but does not always reduce it. Effects depend on the GLP-1 product and the other medicine. The Mounjaro interaction section and Ozempic clinical-pharmacology data illustrate why a single spacing rule is unreliable.

Also disclose other GLP-1 or tirzepatide products, insulin secretagogues, supplements and oral medicines requiring close monitoring. The named weight-management labels advise against coadministration with another GLP-1 product. This checklist does not cover every possible interaction.

Age Considerations

Children and adolescents: Mounjaro is approved for type 2 diabetes from age 10. Wegovy injection has an obesity indication from age 12; its tablets and 7.2 mg injection do not have established pediatric use. Zepbound has adult indications, not an established pediatric weight-management approval. Do not transfer an age limit from one brand, formulation or indication to another.

Older adults: There is no single upper-age exclusion. Assess nutrition, frailty, other medicines, kidney function and treatment goals. Older age or reduced kidney function alone does not create an automatic semaglutide or tirzepatide dose reduction; tolerability and the exact product still matter.

Pre-Start Safety Checklist: Before Beginning GLP-1

Related Resources

Explore Wegovy side effects and management. Learn about GLP-1 insurance coverage. Understand Zepbound side effects in detail.