Contraindications for Wegovy: when this treatment is not the right fit

You've been told you might not be eligible, here's what the prescriber is actually weighing up

It's a situation our prescribers hear about most weeks: someone fills in their consultation form, mentions a past diagnosis, and gets back a message asking for more information or saying the treatment isn't suitable. That can feel frustrating, particularly if the condition feels old or well-controlled. The reason isn't bureaucracy. Wegovy is a powerful medicine with a specific pharmacological profile, and a handful of conditions interact with it in ways that make the risk outweigh the benefit.

The clearest absolute contraindication is a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2. Rodent studies found GLP-1 receptor activation caused thyroid C-cell tumours; the clinical relevance in humans is uncertain, but the licensed guidance rules out treatment for anyone with that background regardless. There is no dose at which this becomes safe. If this applies to you, semaglutide (in any form, including Ozempic and the Wegovy injection) is not a path to pursue.

Serious hypersensitivity to semaglutide or any excipient in the formulation is also an absolute contraindication. If you have had an allergic reaction to a GLP-1 medicine previously, your prescriber will want to know exactly what happened and may rule out treatment entirely. The NHS semaglutide page lists the signs of serious reaction to watch for in people starting treatment for the first time.

Conditions that don't automatically rule it out but genuinely change the picture

Pancreatitis sits in its own category. Active acute pancreatitis is a contraindication. A history of pancreatitis requires careful prescriber assessment, it does not automatically rule Wegovy out, but any prescriber worth their registration will want a detailed history before proceeding. In January 2026, the MHRA issued a Drug Safety Update specifically highlighting acute pancreatitis as a known, if infrequent, serious risk with GLP-1 medicines; the update reinforced the importance of stopping treatment and seeking urgent help if severe, persistent stomach pain develops, particularly pain that radiates to the back. You can report any suspected side effects through the Yellow Card scheme.

Severe gastrointestinal disease (conditions where slowed gastric emptying would be actively harmful, such as gastroparesis) is typically a contraindication. Wegovy slows the gut; in an already-impaired GI tract that effect can cause serious problems. Inflammatory bowel disease in an active flare is another reason a prescriber might pause.

Renal impairment matters too, though less absolutely. Wegovy does not require dose adjustment for kidney disease in its own right, but severe dehydration from GI side effects can put the kidneys under real pressure. Someone with already-compromised renal function needs that risk factored in carefully. The same logic applies to severe hepatic impairment, limited data means prescribers proceed with caution, not a blanket yes. If you want to understand the broader clinical criteria Wegovy requires, that page covers BMI thresholds, comorbidities and the eligibility framework in full.

Pregnancy, contraception and the timing question

Wegovy is not recommended in pregnancy, during breastfeeding, or for anyone actively trying to conceive. This is not a soft advisory. Animal reproductive studies raised concerns, and the human data required to establish safety simply does not exist. A prescriber will ask about pregnancy plans directly.

The contraception picture is more nuanced and is a practical issue for anyone on the oral contraceptive pill. For tirzepatide (Mounjaro) there is specific guidance about adding a barrier method during dose increases; with semaglutide the evidence for reduced pill absorption is less pronounced, but the NHS still advises discussing contraception with a doctor before starting. If you're exploring how the two medicines compare on this and other dimensions, the Wegovy versus Ozempic page clarifies the semaglutide products, and a broader comparison of injectable options is worth covering at consultation. For the full washout guidance before trying to conceive, your prescriber and the patient information leaflet are the authoritative sources, timings differ by medicine and are not something to navigate from general content.

Understanding the preparation steps before starting Wegovy can help you bring any relevant history to the consultation clearly, which makes that conversation faster and more useful for everyone.

Medicines that interact, and what to do if you take them

Wegovy slows gastric emptying, which changes how quickly other oral medicines are absorbed. This matters most for medicines with narrow therapeutic windows, anticoagulants, certain antibiotics, thyroid drugs. None of this is automatically a dealbreaker, but your prescriber needs a complete medicine list. Don't underestimate over-the-counter medicines and supplements here.

Insulin and other blood-glucose-lowering agents are a particular consideration. Wegovy lowers blood sugar; combining it with insulin or sulfonylureas increases the hypoglycaemia risk. Prescribers managing type 2 diabetes alongside weight treatment typically adjust those medicines downward first. This is a clinical conversation, not a self-managed one.

If you want to understand how the dosing schedule works alongside any existing treatment, the Wegovy directions page covers the titration pathway. For the storage and handling practicalities once you start, step-by-step Wegovy instructions covers the injection process clearly. And if you're thinking about the cost of treatment relative to what's actually included, the Wegovy pricing page explains how private prescription costs are structured.

None of the above replaces a proper clinical assessment. A prescriber working through your full medical history, current medicines and circumstances is the only way to get a clear answer. If you'd like that review, the free consultation at nume's treatment page is where to start, the same-day clinical review is done by a GPhC-registered prescriber, not software.