Who the labels say should not take a GLP-1
All four of these labels open with the same boxed warning and name the same two contraindications. Below that they diverge: the warnings and precautions section runs to ten subsections on three of them and eleven on the fourth, and not every warning appears on every product. This page prints the shared parts as quotations and the divergent parts as a census.
Ellis Brandt built this site’s grading methodology and maintains it. Sections 4 and 5 of all four labels read end to end. Last re-read 2026-09-04.
Not medical advice. Semaglutide and tirzepatide are prescription-only medicines, and whether one is appropriate for you is a question for a licensed clinician who knows your history. This page reports what the FDA-approved prescribing information says and nothing else; it is not written or reviewed by a clinician. See the medical disclaimer.
The two contraindications
A personal or family history of medullary thyroid carcinoma, or Multiple Endocrine Neoplasia syndrome type 2. And a serious hypersensitivity reaction to the active ingredient or to any excipient in the product.
Identical on all four labels, read 2026-09-04.
The boxed warning
Every one of these four labels carries a boxed warning — the strongest warning the FDA applies — and all four carry the same one, headed WARNING: RISK OF THYROID C-CELL TUMORS.
Mounjaro’s, in full as the label states it: “In both male and female rats, tirzepatide causes dose-dependent and treatment-duration-dependent thyroid C-cell tumors at clinically relevant exposures. It is unknown whether MOUNJARO causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans as human relevance of tirzepatide-induced rodent thyroid C-cell tumors has not been determined”.
The semaglutide labels say the same thing about their own molecule. Ozempic: “In rodents, semaglutide causes dose-dependent and treatment-duration-dependent thyroid C-cell tumors at clinically relevant exposures. It is unknown whether OZEMPIC causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans as human relevance of semaglutide-induced rodent thyroid C-cell tumors has not been determined”.
Two things in that wording are worth reading precisely, because they are usually paraphrased away. The finding is in rodents. And the labels say the human relevance of that finding has not been determined — not that it has been ruled out, and not that it has been established.
Each boxed warning then adds the same practical instruction: counsel patients about the symptoms of thyroid tumours — “a mass in the neck, dysphagia, dyspnea, persistent hoarseness” — and note that “routine monitoring of serum calcitonin or using thyroid ultrasound is of uncertain value for early detection of MTC” in patients taking these drugs.
The contraindications
Section 4 is the short list — the circumstances in which the label says the drug should not be used at all. On all four it holds the same two entries.
| Label | Thyroid contraindication | Hypersensitivity contraindication |
|---|---|---|
| Ozempic | A personal or family history of medullary thyroid carcinoma, or Multiple Endocrine Neoplasia syndrome type 2 | A serious hypersensitivity reaction to semaglutide or to any of the excipients in Ozempic |
| Wegovy | A personal or family history of medullary thyroid carcinoma, or Multiple Endocrine Neoplasia syndrome type 2 | A serious hypersensitivity reaction to semaglutide or to any of the excipients in Wegovy |
| Mounjaro | A personal or family history of medullary thyroid carcinoma, or Multiple Endocrine Neoplasia syndrome type 2 | A serious hypersensitivity reaction to tirzepatide or to any of the excipients in Mounjaro |
| Zepbound | A personal or family history of medullary thyroid carcinoma, or Multiple Endocrine Neoplasia syndrome type 2 | A serious hypersensitivity reaction to tirzepatide or to any of the excipients in Zepbound |
Which warnings appear on which label
Section 5 is longer and it is not identical across the four. The table below is a census of the subsection titles in each label’s warnings and precautions section, read end to end on 2026-09-04. A blank is an absence from that document, not a statement that the risk does not exist.
| Warning | Ozempic | Wegovy | Mounjaro | Zepbound |
|---|---|---|---|---|
| Risk of thyroid C-cell tumors | 5.1 | 5.1 | 5.1 | 5.1 |
| Acute pancreatitis | 5.2 | 5.2 | 5.2 | 5.5 |
| Acute gallbladder disease | 5.9 | 5.3 | 5.8 | 5.4 |
| Hypoglycemia | 5.5 | 5.4 | 5.3 | 5.7 |
| Acute kidney injury due to volume depletion | 5.6 | 5.5 | 5.5 | 5.3 |
| Severe gastrointestinal adverse reactions | 5.7 | 5.6 | 5.6 | 5.2 |
| Hypersensitivity reactions | 5.8 | 5.7 | 5.4 | 5.6 |
| Diabetic retinopathy complications | 5.3 | 5.8 | 5.7 | 5.8 |
| Pulmonary aspiration during general anesthesia or deep sedation | 5.10 | 5.10 | 5.9 | 5.9 |
| Never share a pen between patients | 5.4 | 5.11 | 5.10 | 5.10 |
| Heart rate increase | — | 5.9 | — | — |
The cells hold the subsection number in that label, so a reader can go to the document and check. Eleven warnings appear across the four; ten are shared and one — heart rate increase — appears on the Wegovy label alone among these four. Wegovy is also the only one of the four whose section 5 runs to eleven subsections rather than ten.
Pregnancy, and a number that only two of these labels give
Both semaglutide labels give a discontinuation interval before a planned pregnancy. Neither tirzepatide label gives one. This is a real difference between the documents and it is reported as such — the semaglutide interval is not borrowed across to fill the empty cells.
| Label | What the label states |
|---|---|
| Ozempic | Discontinue in women at least 2 months before a planned pregnancy, because of the long washout period for semaglutide. |
| Wegovy | Because of the potential for fetal harm, discontinue at least 2 months before planning to become pregnant, to account for the long half-life of semaglutide. |
| Mounjaro | [needs citation] — section 8.3 of this label covers contraception only and states no pre-pregnancy interval. |
| Zepbound | [needs citation] — the label advises patients to discontinue when a pregnancy is recognised, and states no interval before a planned one. |
What would close those two markers is a statement in the tirzepatide labels themselves, or a source of comparable standing. Until one exists this site prints the gap rather than a plausible number. Both tirzepatide labels do carry the oral-contraceptive precaution described on the drug interactions page, which is a different question and is often confused with this one.
Sources
| Label | Applicant on the label | SPL version | Label effective date | Where it was read |
|---|---|---|---|---|
| Ozempic (semaglutide) | Novo Nordisk Pharmaceutical Industries, LP | 20 | 2026-06-01 | DailyMed, set id adec4fd2-6858-4c99-91d4-531f5f2a2d79 |
| Wegovy (semaglutide) | Novo Nordisk Pharmaceutical Industries, LP | 19 | 2026-06-18 | DailyMed, set id ee06186f-2aa3-4990-a760-757579d8f77b |
| Mounjaro (tirzepatide) | Eli Lilly and Company | 40 | 2026-08-27 | DailyMed, set id d2d7da5d-ad07-4228-955f-cf7e355c8cc0 |
| Zepbound (tirzepatide) | Eli Lilly and Company | 40 | 2026-08-28 | DailyMed, set id 487cd7e7-434c-4925-99fa-aa80b1cc776b |
Each capture was checked against its own document title before anything was quoted from it, and a nonsense set id was fetched through the identical method in the same session as a control — it returned 404 with an empty body, so a document that returns is a document that exists.
More, read from the same labels
- Semaglutide vs tirzepatidereading the label
What the four FDA-approved labels say each molecule is, what each is approved to treat, and where the two differ.
- Dose escalation schedulesreading the label
The starting dose, the escalation interval and the maximum dose each label sets, and why they are not interchangeable.
- Side effect ratesreading the label
What each label reports for nausea, vomiting, diarrhoea and constipation — and the sentence every label prints above those numbers.
- Missed dose rulesreading the label
The window each label gives for a late dose, and the minimum gap it requires when the injection day changes.
- Drug interactionsreading the label
Insulin and sulfonylureas, oral medications, and the oral-contraceptive precaution that appears on two of these four labels and not the other two.
- Buying one onlinereading the label
The agency's own warning signs for a telehealth GLP-1 seller, its 28-day vial rule, and what it says about drugs that arrive warm.