Choosing a weight medicine is a decision between you and your health care professional, and your current health issues, other medicines and family medical history are among the factors. Body mass index, or BMI, is one measure health care professionals use to help decide whether you might benefit from a weight medicine at all (see Why one BMI can get a no in one place and a yes in another). For Wegovy, which is semaglutide and comes as an injection or a tablet, and Zepbound, which is tirzepatide, the history that bears on each medicine is set out in its label, which includes prescribing information for health care professionals and a Medication Guide written for patients and their families.
Besides medullary thyroid cancer and MEN 2, is anything an automatic no?
Yes, one more entry: a serious allergic reaction in the past to the medicine or to one of its ingredients. According to the current Wegovy and Zepbound labels, the do-not-use list has two entries: that reaction, to semaglutide or tirzepatide or to anything else in the medicine, and a personal or family history of medullary thyroid carcinoma, or MTC, a type of thyroid cancer, or having MEN 2, an endocrine system condition. The serious allergic reactions reported with each medicine include anaphylaxis, a life-threatening type of allergic reaction, and angioedema, a swelling under the skin instead of on its surface.
The thyroid entry covers your family's history as well as your own, so before the assessment ask your parents, brothers, sisters or other relatives whether anyone has had MTC or MEN 2 (see Medullary thyroid cancer in the family rules out one weekly injection).
Both medicines belong to the group called GLP-1 receptor agonists, and a serious reaction to a different medicine in that group is not on the do-not-use list. Under both labels, prescribers should use caution with anyone who has had either of those reactions to another medicine in the group, because it is not known whether that person is predisposed to them with this medicine too.
An old episode of pancreatitis is not on the do-not-use list. Pregnancy is not on it either, but that is not a yes: under both labels, a recognized pregnancy means stopping the medicine. A physician who reads the rest of your history can still decide that a medicine is not right for you.
What else the prescriber needs to hear about, with what each item changes
Before you start, tell the prescriber about all of your medical conditions, not only the ones below. Each item comes with an instruction for the prescriber: the pancreas and kidney instructions apply to everyone who takes the medicine, and the others to people with that condition or medicine.
- Pancreas problems, now or in the past. If pancreatitis is suspected after someone starts, the prescriber should stop the medicine, under the Wegovy and Zepbound labels alike.
- Kidney problems, now or in the past. The prescriber should monitor your kidney function if you report side effects that could dehydrate you, such as vomiting or diarrhea (see With kidney disease, a day of vomiting needs a plan made while you are well).
- Severe stomach problems, such as gastroparesis, a stomach that empties slowly. Neither Wegovy nor Zepbound is recommended for someone with severe gastroparesis. The prescriber decides whether yours counts as severe.
- Diabetic retinopathy in your history. It is an eye condition that can cause vision loss in people who have diabetes, and someone with that history should be monitored for it getting worse, according to the Wegovy and Zepbound labels.
- Insulin, or a diabetes medicine such as a sulfonylurea. When someone starts either weight medicine, the prescriber should consider lowering the dose of their insulin or sulfonylurea to reduce the risk of low blood sugar (see A weekly weight medicine can change how some of your other tablets work).
- A surgery or procedure planned with anesthesia or deep sedation. Either medicine may make the stomach empty more slowly, which may lead to complications with anesthesia or deep sedation, so if you take one, tell all your healthcare providers before you are scheduled for surgery or another procedure (see Tell the anesthesia team about your weekly weight medicine).
- Another medicine of this type. Using Wegovy with other semaglutide products or any other GLP-1 receptor agonist is not recommended, and Zepbound should not be used with other tirzepatide products or any GLP-1 receptor agonist.
Tell the prescriber before you start if you are pregnant or breastfeeding, or are planning a pregnancy. Semaglutide may cause fetal harm, according to the Wegovy label, and for someone taking it for weight, it is stopped when a pregnancy becomes known, and at least two months before trying for one, because semaglutide remains in the bloodstream for weeks after the last dose. Breastfeeding is not recommended during treatment with Wegovy tablets, and it is not known whether Wegovy taken by injection passes into breast milk. According to the Zepbound label, tirzepatide may cause fetal harm and may pass into breast milk, and it is stopped once a pregnancy is recognized. Birth control pills taken by mouth may not work as well while using tirzepatide, and prescribers should advise anyone taking them to change to a method that is not swallowed, or to back the pill up with a barrier method, in either case for a set time after starting and after each dose increase; the prescriber can tell you how long. That instruction is for tirzepatide, and under the Wegovy label there is none like it. Ask the prescriber, too, how to feed a baby while taking either medicine (see Can a weekly weight injection make the pill less reliable?).
Depression, past or present, is part of the medical history to tell the prescriber about, and so is a past eating disorder (see A past eating disorder belongs in your weight-care medical history). Neither current label carries a warning about suicidal thoughts and behavior, but according to the FDA, anyone taking these medicines should tell their health care professional about new or worsening depression, suicidal thoughts, or any unusual change in mood or behavior once treatment has started (see Flat and tired for weeks while eating less? Book a doctor's visit). If you are in distress now, call or text 988 at any hour to reach the 988 Suicide & Crisis Lifeline; when a life is at immediate risk, call 911.
Which papers to dig out before the assessment
The papers worth finding are a written list of your medicines and allergies, and the latest test result or report for each condition above that you have had. A medication list keeps your allergies and medical conditions in one place with every prescription and nonprescription medicine, vitamin and supplement you take, each by name and by what you take it for. Keep a copy of it with you, and have it to hand for the assessment. Add any medicine of this type you have taken before, and any medicine that caused a serious allergic reaction, with what happened.
Before any appointment, know your current medical conditions, past surgeries and illnesses. Include a weight-loss operation, however long ago. It is on neither do-not-use list, but according to the Wegovy prescribing information, people with a history of bariatric surgery, a risk factor for low blood sugar, had more episodes of serious low blood sugar on the injection than on a placebo in a trial (see Had a sleeve or bypass? Bring the operation to any new weight care).
| In your history | Where the labels put it | The record to find |
|---|---|---|
| MTC or MEN 2, in you or your family | Do-not-use list, both labels | What your relatives can tell you |
| A serious allergic reaction to semaglutide, tirzepatide or an ingredient | Do-not-use list, both labels | The medicine's name and what happened |
| Pancreatitis or another pancreas problem | Tell the prescriber, named in both Medication Guides | Amylase and lipase blood tests, imaging reports and any cause found |
| Kidney problems | Tell the prescriber, named in the Wegovy Medication Guide | Your latest GFR blood test and urine albumin test |
| Gastroparesis or another severe stomach problem | Tell the prescriber, named in the Zepbound Medication Guide | The result of a gastric emptying test |
| Diabetic retinopathy | Tell the prescriber, named in both Medication Guides | The report of your last dilated eye exam |
| A planned surgery or procedure with anesthesia or deep sedation | Tell the prescriber, named in both Medication Guides | The date and the kind of procedure |
Mention kidney and stomach problems whichever medicine you are offered, since under each Medication Guide you tell the prescriber about all of your medical conditions. For an old pancreatitis episode, ask the hospital or clinic that treated it for the blood tests, the imaging and any cause it found, since doctors use lab and imaging tests to diagnose pancreatitis and find its causes. Health care providers check for kidney disease with a blood test called GFR, which shows how well your kidneys are filtering your blood, and a urine test for albumin, so ask the office that ordered them for your latest result of each. Eye doctors check for diabetic retinopathy in a dilated eye exam, which is important to have at least once a year if you have diabetes; ask your eye doctor's office for the latest report (see Type 2 diabetes and an overdue eye exam: book it before weight care). For gastroparesis, ask the doctor who ordered your gastric emptying scan, or a similar test, for the result (see Gastroparesis diagnosed years ago still matters for a weekly injection).
Why the lists online disagree about who cannot take these medicines
A list you find online may predate the latest label changes or carry only part of a label, and the two labels themselves differ. A federal summary of weight medicines last reviewed in June 2024 gives the thyroid entry alone as a reason not to take Wegovy or Zepbound, without the allergy entry. The same summary advises against weight-loss medications in pregnancy or when planning one and asks you to tell your doctor about any allergies, and it still describes reported suicidal thoughts or actions as under FDA review.
In January 2026, the FDA asked the makers of Wegovy, Zepbound and one other medicine of the same type to remove the warning about suicidal behavior and ideation from their labels, after a comprehensive review that, according to the agency, found no increased risk. The section came off the Wegovy and Zepbound labels in February 2026, so any copy of either label that still has a section on suicidal behavior predates that change.
To read both lists yourself, look the medicine up on DailyMed, where the labeling is the most recent version a maker has submitted to the FDA and is currently using; it may not be identical to the most recent FDA-approved labeling or to the leaflet that comes with the medicine. The do-not-use list is the Contraindications section of the prescribing information, and the list of conditions to tell the prescriber about is in the Medication Guide.
If you use NicoCares, its eligibility check asks about your medical history and whether you have taken weight medication before, so that a physician who holds a license in your state can make the clinical decision. That physician may prescribe semaglutide or tirzepatide in a compounded form. Compounded drugs do not go through FDA approval, and the lists here come from the labels of the two approved medicines. Once you have an account, ask your care team, through the secure messaging Spruce Health hosts for you and them, which medicine's label your history is checked against, and keep the papers above to hand for the health questions.
