Three levels of wording, and why documents disagree
Labels use graded wording. "Contraindicated" means the document says the medicine should not be used in that situation. "Not recommended" is a strong caution that leaves the final judgement to the prescriber. "Use with caution" or "monitor" means the medicine may be used, with extra attention. Knowing which level applies explains why your prescriber asks certain questions before writing a prescription.
Regulators also file the same concern in different places. The US labels put the thyroid exclusion in section 4; the European product information keeps only allergy in section 4.3 and handles everything else as a warning in section 4.4 [1][9]. Canada lists pregnancy for tirzepatide and dulaglutide as a contraindication [12][13]. None of these is wrong; they reflect how each agency weighs the same data. Zepbound® and Foundayo™ have no EU product information; in the EU, tirzepatide is sold as Mounjaro®.
| Document | MTC or MEN 2 | Serious allergy to the medicine | Pregnancy or breastfeeding |
|---|---|---|---|
| Wegovy®, Ozempic®, Rybelsus®, US label, section 4 [1][2][3] | Yes | Yes | No; covered in sections 8.1–8.3 |
| Zepbound®, Mounjaro®, US label, section 4 [4][5] | Yes | Yes | No; covered in sections 8.1–8.3 |
| Foundayo™, US label, section 4 [6] | Yes | Yes | No; covered in sections 8.1–8.3 |
| Saxenda®, Trulicity®, US label, section 4 [7][8] | Yes | Yes | No; covered in section 8 |
| Wegovy®, Mounjaro®, Victoza®, EU SmPC, section 4.3 [9][10][11] | No | Yes, the only one | No; section 4.6 advises against use in pregnancy |
| Zepbound®, Canadian monograph, section 2 [12] | Yes | Yes, including benzyl alcohol | Pregnancy |
| Trulicity®, Canadian monograph, section 2 [13] | Yes | Yes | Pregnancy and breastfeeding |
The thyroid exclusion
The thyroid contraindication is linked to the boxed warning on the US labels. Semaglutide, tirzepatide, liraglutide and dulaglutide caused thyroid C-cell tumors in rodent studies, and the labels state that it is unknown whether this happens in humans [1][4][8]. Because of that uncertainty, people with MTC in the family or with MEN 2, an inherited syndrome in which tumors form in several glands, are excluded. Foundayo™ carries the same exclusion even though it caused no tumors in rodents, because it acts on the human receptor [6].
Other thyroid conditions are not listed. Your prescriber may still ask about relatives with thyroid cancer and its type, so it helps to find out before the appointment. The article on the thyroid warning covers the evidence in detail.
Allergy to the medicine, or to a similar one
- Every US label excludes people who have had a serious hypersensitivity reaction to the active ingredient or any inactive ingredient; anaphylaxis and angioedema have been reported (Wegovy® 5.7, Ozempic® 5.8, Zepbound® 5.6, Mounjaro® 5.4, Foundayo™ 5.6) [1][2][4][5][6].
- A past anaphylaxis or angioedema with another GLP-1 medicine is not an exclusion, but the labels ask for caution, because it is unknown whether such people are predisposed to the same reaction [1].
- The Canadian Zepbound® monograph names benzyl alcohol, a preservative in the multi-dose presentations, among the ingredients a person may be allergic to [12]. The EU Mounjaro® document gives the amount in each KwikPen dose [10].
Situations the labels do not recommend
- Severe gastroparesis: every US label says the medicine is not recommended when stomach emptying is severely delayed (Wegovy® 5.6, Ozempic® 5.7, Rybelsus® 5.6, Zepbound® 5.2, Mounjaro® 5.6, Foundayo™ 5.3, Saxenda® 5.7, Trulicity® 5.6) [1][2][3][4][5][6][7][8]. The EU documents add that tirzepatide has not been studied in severe gastrointestinal disease [10].
- Combining GLP-1 medicines: the Wegovy®, Zepbound®, Saxenda® and Foundayo™ labels say in section 1 that they are not recommended with other products containing the same ingredient or with any other GLP-1 receptor agonist [1][4][6][7].
- Foundayo™ only: not recommended with severe liver impairment (Child-Pugh C, section 8.6), and strong CYP3A4 inducers are to be avoided with it (section 7.1). Some other medicines change its dose ceiling [6].
- EU only: semaglutide (Wegovy®) has not been studied in type 1 diabetes, severe kidney or liver impairment, NYHA class IV heart failure or alongside other weight-loss products, and is not recommended in those groups; liraglutide (Victoza®) should not be used in type 1 diabetes or diabetic ketoacidosis, and is not recommended in inflammatory bowel disease [9][11].
Conditions that call for caution and closer follow-up
- Pancreatitis: every label tells clinicians to stop the medicine if pancreatitis is suspected (section 5.2 in most labels, 5.5 in Zepbound®) [1][4]. A past episode is not a US contraindication; the EU documents ask for caution, and note that tirzepatide was not studied in people with a history of it [9][10].
- Diabetic eye disease: in type 2 diabetes, people with a history of diabetic retinopathy are to be monitored (Wegovy® 5.8, Ozempic® 5.3, Mounjaro® 5.7, Zepbound® 5.8) [1][2][4][5]. The EU Wegovy® document does not recommend it with uncontrolled or unstable retinopathy, and describes an increased risk of NAION, a sudden loss of vision from the optic nerve [9].
- Kidneys: vomiting and diarrhea can dehydrate you, and acute kidney injury has been reported; the labels ask for kidney monitoring in people with those symptoms (Wegovy® 5.5, Zepbound® 5.3) [1][4].
- Gallbladder: gallstones and inflammation have occurred in trials (Wegovy® 5.3, Zepbound® 5.4) [1][4].
- Low blood sugar: insulin or a sulfonylurea taken alongside raises the risk, and their dose may need to change (Wegovy® 5.4, Mounjaro® 5.3) [1][5].
- Mood: the US Wegovy® and Saxenda® labels removed their suicidal thoughts and behavior section in 2026, and the Zepbound® label lists it as removed too; the Canadian Zepbound® monograph still asks clinicians to watch for new or worsening depression or suicidal thoughts [1][7][12].
Pregnancy, breastfeeding and age
Pregnancy is not a US contraindication, but the weight-management labels say to stop once a pregnancy is recognised, and the semaglutide labels ask for a gap of at least two months before a planned pregnancy [1][4]. The EU documents say semaglutide should not be used in pregnancy and that tirzepatide is not recommended [9][10]. NIDDK, part of the US National Institutes of Health, says weight-loss medicines are not for use in pregnancy, when planning one or while breastfeeding [15]. Semaglutide tablets are not recommended while breastfeeding [1][3]. The pregnancy article compares each label in detail.
- Wegovy® injection: approved for weight management from age 12; Wegovy® tablets have not been established in children [1].
- Saxenda®: approved from age 12 in children with obesity who weigh more than 60 kg [7].
- Mounjaro® and Trulicity®: approved for type 2 diabetes from age 10 [5][8].
- Zepbound®, Ozempic® and Foundayo™: safety and effectiveness have not been established in children [2][4][6].
What to tell your prescriber first
The Wegovy® Medication Guide asks you to mention pancreas or kidney problems, type 2 diabetes with a history of diabetic retinopathy, any planned surgery or deep sedation, pregnancy or plans for one, and breastfeeding [1]. MedlinePlus adds gallbladder disease, severe stomach problems including gastroparesis, recent vomiting or diarrhea, being unable to drink fluids, and any planned surgery, including dental surgery [14].
Bring a full medicine list. Insulin and sulfonylureas matter for low blood sugar, and medicines that need precise blood levels matter because these medicines slow the stomach [1]. If you see poorly, the Wegovy® FlexTouch® pen and the Mounjaro® and Zepbound® KwikPen are not recommended for self-injection, and the Medication Guide says you may inject yourself only once your provider decides you can do it safely [1][4][5].
Ozempic®, Wegovy®, FlexTouch®, Rybelsus®, Saxenda® and Victoza® are registered trademarks of Novo Nordisk A/S. Mounjaro®, Zepbound®, Trulicity® and KwikPen® are registered trademarks and Foundayo™ is a trademark of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by Novo Nordisk or Eli Lilly and Company.
When to get help
| Sign | Who to contact | How fast | Source |
|---|---|---|---|
| After a dose: a swollen face, lips, tongue or throat, fainting, or difficulty breathing or swallowing | Emergency services; stop the medicine | Emergency | Medication Guide [1] |
| Severe stomach pain that does not go away, sometimes spreading to the back | Your prescriber, right away; stop the medicine | Today | Medication Guide [1] |
| A sudden loss of vision | An eye examination, promptly | Today | EU SmPC 4.4 [9] |
| You learn you are pregnant | Your prescriber | Today | US labels, section 8.1 [1][4] |
| Changes in vision with type 2 diabetes | Your prescriber | At your next appointment | Medication Guide [1] |
| A relative is diagnosed with MTC or MEN 2 | Your prescriber | At your next appointment | US labels, section 4 [1][4] |
