Who Should Not Take a GLP-1 Medication?

GLP-1 medicines such as semaglutide and tirzepatide have become some of the most talked-about prescriptions in the country, and newer pills such as orforglipron have widened the choice. With so much attention on what these drugs can do, a quieter question often gets skipped: who shouldn’t take them at all, and who needs extra care before starting?

The answer is more specific than many people expect. The official “never” list is short. The “be careful and talk it through” list is longer, and it is where most real-world decisions happen. This guide walks through both, using the FDA prescribing information for the GLP-1 medicines approved for weight management, plus guidance from medical societies.

Educational only. This is not medical advice. Only a licensed clinician who knows your full health history can tell you whether a GLP-1 medicine is safe for you. Do not start, stop or change any medicine based on this article.

The short answer

Across the FDA labels for Wegovy (semaglutide injection and tablets), Zepbound (tirzepatide) and Foundayo (orforglipron), there are two contraindications, meaning situations where the drug should not be used:

1. A personal or family history of medullary thyroid carcinoma (MTC), or multiple endocrine neoplasia syndrome type 2 (MEN 2).
2. A prior serious allergic reaction (for example anaphylaxis or angioedema) to the medicine or any of its ingredients.

Beyond those, the labels say the medicine should be stopped when a pregnancy is recognized, and the weight-management approvals apply only to people who meet specific weight criteria. Then comes a set of conditions where the labels advise caution, monitoring, or say the drug is “not recommended,” such as severe gastroparesis. Those are the situations that need a real conversation with a prescriber.

Contraindications vs warnings: why the difference matters

Drug labels sort risks into categories, and the wording is deliberate.

• A contraindication means the drug should not be used in that situation, full stop.
• A warning or precaution describes a known or possible risk that a clinician should watch for, explain, or plan around. Some warnings lead clinicians to avoid a drug in certain people; others simply call for monitoring.
• “Not recommended” sits in between: the label is steering clinicians away, but it is not written as a formal contraindication.

This matters because online advice often blurs the lines in both directions. On X, clinicians and health writers regularly push back on two common mix-ups: the idea that “any thyroid problem” rules out a GLP-1 (the contraindication is specific to MTC and MEN 2), and the idea that past pancreatitis is a formal contraindication on the label (it is a warning). At the same time, clinicians may still be more conservative than the label. In a Stony Brook Medicine podcast, an obesity medicine physician described a history of pancreatitis and obstructive gallstones as conditions she treats as absolute reasons not to prescribe. Both things can be true: the label sets the minimum, and your clinician may reasonably set a stricter bar for you.

The two firm “do not take” situations

Medullary thyroid cancer or MEN 2

Every GLP-1 medicine approved for weight management carries a boxed warning, the FDA’s most prominent type, about thyroid C-cell tumors. In rodents, semaglutide and tirzepatide caused dose-dependent thyroid C-cell tumors at exposures similar to those in people. Whether this happens in humans is unknown, because the relevance of the rodent findings “has not been determined.”

Orforglipron is an interesting twist. Its label notes that the drug is not pharmacologically active in rats or mice and did not produce tumors in rodents, but because it acts on the same human GLP-1 receptor, it carries the same boxed warning and the same contraindication.

What the labels ask in practice:

• Do not use a GLP-1 if you or a family member has had medullary thyroid carcinoma, or if you have MEN 2.
• Know the symptoms of a thyroid tumor and report them: a lump or swelling in the neck, trouble swallowing, shortness of breath, or hoarseness that doesn’t go away.
• Routine screening is not recommended. The labels say routine calcitonin blood tests or thyroid ultrasounds are of uncertain value for catching MTC early and may lead to unnecessary procedures. Thyroid nodules found on an exam or scan should still be evaluated.

Note what is not on the list: common thyroid conditions such as hypothyroidism or Hashimoto’s. If you have any thyroid history, mention it anyway, along with any thyroid cancer in parents, siblings or children. MTC is rare and is different from the more common papillary thyroid cancer, so the exact diagnosis matters.

A serious allergic reaction to the drug

The second contraindication is a prior serious hypersensitivity reaction to the active drug or any ingredient. The labels note that anaphylaxis and angioedema have been reported. If you develop swelling of the face, lips, tongue or throat, trouble breathing, or a severe rash after a dose, the labels advise stopping the medicine and getting medical help promptly. If you have had anaphylaxis or angioedema with a different GLP-1, tell your clinician; the Wegovy label advises caution because it is unknown whether such people are predisposed to react to Wegovy too.

Pregnancy, trying to conceive and breastfeeding

This is the most important group outside the two contraindications.

Pregnancy. All three labels say weight loss offers no benefit during pregnancy and may cause fetal harm, and that the medicine should be discontinued when a pregnancy is recognized. Animal studies showed harm to developing offspring, and human data are too limited to rule out risk. Pregnancy registries exist for people exposed during pregnancy.

Planning a pregnancy. The Wegovy label advises stopping at least 2 months before a planned pregnancy, because semaglutide has a long half-life and lingers in the body. If you are thinking about pregnancy in the next year, raise it before starting, because it may change which medicine, if any, makes sense.

Birth control pills. Two of these medicines can make oral contraceptives less reliable because they slow stomach emptying, which can change how pills are absorbed:

Medicine	Label advice for people using birth control pills
Zepbound (tirzepatide)	Switch to a non-oral method, or add a barrier method, for 4 weeks after starting and for 4 weeks after each dose increase
Foundayo (orforglipron)	Switch to a non-oral method, or add a barrier method, for 30 days after starting and for 30 days after each dose increase
Wegovy (semaglutide)	The Wegovy label does not include a matching contraception instruction; ask your prescriber

The Zepbound label says hormonal contraceptives that are not taken by mouth, such as a ring, patch, implant or injection, should not be affected.

Breastfeeding. The guidance differs by product. The Wegovy label says breastfeeding is not recommended with Wegovy tablets, because an absorption-enhancing ingredient in the tablet (called SNAC) appears in breast milk and could build up in infants. For the injections, the labels ask clinicians and parents to weigh the benefits of breastfeeding against the clinical need for the drug and any potential risk to the baby. In a small study of 11 breastfeeding women given one dose of tirzepatide, the drug was undetectable in most milk samples, but there are no data on effects on breastfed infants.

People the medicines aren’t approved for

A GLP-1 can be prescribed off-label, but the FDA approvals for weight management cover specific groups, which is a useful guide to who has been studied.

• Adults without obesity or a weight-related condition. The weight-management approvals are for adults with obesity, or with overweight plus at least one weight-related health condition. In the Stony Brook podcast, the obesity medicine physician put people already in a normal weight range at the top of her list of poor candidates. Our guide to who qualifies for GLP-1 weight-loss treatment explains the BMI thresholds and conditions involved.
• Children and teens. The Wegovy injection is approved for ages 12 and older with obesity. The Zepbound label says safety and effectiveness have not been established in pediatric patients.
• People already taking another GLP-1. The Wegovy label says using it with other semaglutide products or any other GLP-1 receptor agonist is not recommended. That includes combining a brand-name product with a compounded one.
• People with type 1 diabetes. The Wegovy label notes that use in type 1 diabetes has not been evaluated.
• Severe liver impairment (orforglipron). The Foundayo label says it is not recommended in people with severe hepatic impairment.

Conditions that call for caution and a careful conversation

These are not automatic exclusions on the labels, but each one changes the risk picture. If any apply to you, your clinician may choose a different medicine, start more slowly, monitor more closely, or advise against treatment.

Condition or situation	What the labels say	What it means for you
Severe gastroparesis	“Not recommended” (Wegovy, Zepbound, Foundayo)	These drugs slow stomach emptying and can cause severe digestive side effects
Past pancreatitis	Warning: stop if pancreatitis is suspected; don’t restart if confirmed	Many clinicians avoid or use extra caution; discuss the cause of your earlier episode
Gallbladder disease	Warning: gallstones and gallbladder inflammation occurred more often than with placebo	Know the symptoms; rapid weight loss itself raises gallstone risk
Kidney disease	Warning: acute kidney injury, mostly linked to dehydration from vomiting or diarrhea	Kidney function may be checked, especially early on
Type 2 diabetes on insulin or a sulfonylurea	Warning: higher risk of low blood sugar	Your prescriber may lower those doses and ask you to monitor glucose
Diabetic retinopathy	Warning: monitor for progression in people with type 2 diabetes	Keep up with eye exams and report vision changes
Planned surgery or sedation	Warning: aspiration during anesthesia has been reported	Tell your care teams; follow their pre-procedure instructions
Oral medicines with a narrow dosing margin (for example warfarin)	Zepbound label: slower stomach emptying can affect absorption of oral medicines; monitor these drugs	Some medicines may need closer monitoring

Severe gastroparesis and other digestive conditions

Gastroparesis is a condition in which the stomach empties too slowly. GLP-1 medicines slow stomach emptying on purpose, which helps people feel full, so adding them to an already slow stomach can make things worse. All three labels now say these drugs are not recommended in severe gastroparesis.

The labels also highlight severe digestive side effects. In weight-loss trials, severe gastrointestinal reactions were reported in 4.1% of people on Wegovy injection versus 0.9% on placebo, and in 1.7% to 3.1% of people on Zepbound (depending on dose) versus 1% on placebo. If you already live with significant reflux, chronic nausea, a history of bowel obstruction, or a motility disorder, make sure your clinician knows. Our guides to GLP-1 nausea and constipation and diarrhea cover the common, milder side effects.

A history of pancreatitis

Acute pancreatitis, including rare severe forms, has been seen in people taking GLP-1 medicines. The labels tell clinicians to stop the drug promptly if pancreatitis is suspected and not to restart it if pancreatitis is confirmed. Symptoms to know: persistent, severe abdominal pain, sometimes spreading to the back, with or without vomiting.

Earlier versions of the Wegovy label noted limited experience in people with a history of pancreatitis and said it was unknown whether they face a higher risk. That uncertainty is why many prescribers are cautious. If your past pancreatitis had a clear cause that has been dealt with, such as gallstones that were removed, the discussion may be different from repeated episodes without a clear cause.

Gallbladder disease

Gallstones (cholelithiasis) and gallbladder inflammation (cholecystitis) occurred more often with these medicines than with placebo in trials. In adult Wegovy weight-loss trials, gallstones were reported in 1.6% of people on the drug versus 0.7% on placebo. Fast weight loss raises gallstone risk on its own, but the Wegovy label notes the difference remained even after accounting for the amount of weight lost. Our article on GLP-1s and gallbladder problems explains the symptoms that need prompt attention.

Kidney problems and dehydration

Acute kidney injury, in some cases needing dialysis, has been reported, mostly in people who became dehydrated from nausea, vomiting or diarrhea. The Wegovy label notes kidney side effects were more frequent in people with existing kidney impairment and during dose increases. If you have chronic kidney disease, your clinician may check kidney function when you start and if you have significant digestive side effects. Our guide to fiber and hydration on GLP-1s covers practical ways to keep fluids up when appetite drops.

Type 2 diabetes medicines and diabetic eye disease

GLP-1s lower blood sugar. On their own, they rarely cause dangerous lows, but combined with insulin or a sulfonylurea (such as glipizide or glimepiride), the risk of hypoglycemia rises. The labels advise clinicians to consider lowering those doses when starting and to monitor blood glucose. Know the signs of low blood sugar, such as shakiness, sweating, confusion, a fast heartbeat or dizziness.

People with type 2 diabetes and diabetic retinopathy should have their eyes monitored, because complications have been reported in semaglutide trials.

Surgery, endoscopy and sedation

Because GLP-1s slow stomach emptying, food can remain in the stomach longer than expected, and the labels warn that pulmonary aspiration (stomach contents entering the lungs) has been reported during anesthesia or deep sedation.

You’ll see conflicting advice online about stopping a week or two beforehand. The most widely cited guidance, published in 2024 by the American Society of Anesthesiologists, the American Gastroenterological Association and three surgical and obesity societies, says most people can continue their GLP-1 before elective procedures. For those at higher risk, such as people in the dose-escalation phase, on higher doses, or with nausea, vomiting, bloating or constipation, the care team may recommend a liquid-only diet for at least 24 hours before the procedure, adjust the anesthesia plan, or postpone elective surgery until symptoms settle. If holding the drug is chosen, the guidance suggests skipping a weekly dose the week before. The key step is simple: tell every surgeon, anesthesiologist and endoscopist that you take a GLP-1, and follow their plan.

Heart rate and blood pressure

GLP-1s can raise resting heart rate slightly; the Wegovy label reports average increases of 1 to 4 beats per minute in adults. Low blood pressure and fainting were uncommon but more frequent than with placebo, especially in people also taking blood pressure medicines and those losing fluids from digestive side effects. If you have a heart rhythm problem or take several blood pressure medicines, your clinician may want to monitor you more closely.

Eating disorders: a gap in the evidence

None of the labels list eating disorders, but specialists urge caution. A 2024 review in the International Journal of Eating Disorders found no studies of GLP-1 medicines in people with anorexia nervosa, bulimia nervosa or other eating disorders apart from binge eating disorder, and said the drugs could possibly worsen or contribute to eating disorder symptoms. The authors recommend that prescribers screen for eating disorders before prescribing and watch for disordered eating afterward.

The National Eating Disorders Association lists potential risks that include misuse by people with restrictive or purging eating disorders, rapid weight loss and malnourishment, and difficulty eating at regular intervals. A 2024 commentary in Obesity Reviews, written by obesity medicine and psychiatry specialists, described the risk that these drugs can suppress appetite so much that eating falls dangerously low, and urged screening, monitoring for food aversion and dehydration, and team-based care.

If you have a current or past eating disorder, it doesn’t automatically mean a GLP-1 is off the table for everyone, but it should be part of the conversation, ideally with input from a clinician experienced in eating disorders.

What changed on the labels in 2026

If you read older articles, you may see a warning about suicidal thoughts and behavior. In January 2026, FDA announced that a comprehensive review found no increased risk of suicidal ideation or behavior with GLP-1 medicines. The review included a meta-analysis of 91 placebo-controlled trials with 107,910 participants, which also found no increased risk of anxiety, depression, irritability or psychosis. FDA asked for the warning to be removed from the Saxenda, Wegovy and Zepbound labels, and the current Wegovy label lists the section as removed in February 2026.

That doesn’t mean mental health is irrelevant. FDA still advises anyone experiencing depression or suicidal thoughts to talk with a health care professional. If you are in crisis, call or text 988 to reach the Suicide and Crisis Lifeline.

Recent labels also added or expanded wording on severe digestive side effects, kidney injury from dehydration, and aspiration during anesthesia, and the Wegovy pen label now warns never to share a pen between people, even with a new needle.

Questions to bring to your appointment

A good GLP-1 assessment covers your full history, not just your weight. Before your visit, it helps to note:

• Any thyroid cancer in you or your family, and any MEN 2 diagnosis.
• Past allergic reactions to medicines, especially injectables.
• Past pancreatitis, gallstones or gallbladder surgery.
• Digestive conditions: gastroparesis, chronic reflux, bowel obstruction, inflammatory bowel disease.
• Kidney or liver disease.
• Diabetes and every diabetes medicine you take, plus your last eye exam.
• Pregnancy plans, breastfeeding, and your contraception method.
• Any planned surgery or procedure.
• Eating disorder history, current or past.
• All medicines and supplements, including any compounded or online GLP-1 product.

Our guide on how to get a GLP-1 prescription explains what a proper screening usually looks like, whether in person or by telehealth. A prescriber who never asks about these topics is a red flag; see our checklist for spotting unsafe online GLP-1 sellers.

If a GLP-1 isn’t right for you

Being a poor candidate for one GLP-1 doesn’t always rule out the whole class, and it doesn’t rule out treatment for weight-related health problems. Depending on the reason, a clinician might suggest a different GLP-1 product, a slower dose schedule, an older weight-management medicine, a structured lifestyle program, or a referral to an obesity medicine specialist or bariatric surgery team.

Foundational habits still matter for everyone. Our guides on what a calorie deficit is, how fast you can safely lose weight, walking for weight loss and strength training are a good place to start. To compare the approved options, see which GLP-1s are FDA-approved for weight loss and GLP-1 pills vs injections.

The bottom line

The official list of people who should never take a GLP-1 weight-loss medicine is short: anyone with a personal or family history of medullary thyroid cancer or MEN 2, and anyone who has had a serious allergic reaction to the drug. Pregnancy is also a clear stop. The much longer list of cautions, from severe gastroparesis and past pancreatitis to insulin use, eating disorders and upcoming surgery, is where careful, individual judgment comes in.

The best protection is a thorough conversation with a licensed clinician who knows your full history, and a prescriber who is willing to say “not this medicine” when that’s the right answer.

Explore more in our GLP-1 Guide, the Side Effects hub, and our First 30 Days guide and Managing Side Effects guide.