Which medications interact with Wegovy, and what should you tell your prescriber?

Step 1: understand why Wegovy changes drug absorption in the first place

Semaglutide reduces appetite partly by slowing gastric emptying, the rate at which the stomach passes its contents into the small intestine. That mechanism is central to how Wegovy works, but it also means any oral medicine taken around the same time may be absorbed more slowly or inconsistently. For drugs where timing and peak concentration matter, that shift can be clinically significant.

This isn't unique to Wegovy. It applies across GLP-1 medicines as a class, and the degree of effect varies between individuals and between dose levels. Higher maintenance doses tend to slow gastric emptying more than starter doses, which is part of why your prescriber reviews your full medication list at each stage rather than just at the beginning. A thorough overview of the semaglutide interaction profile is held in the BNF's semaglutide monograph, written for clinicians managing exactly these questions.

The practical implication: if you're on any medicine whose absorption window is narrow or whose clinical effect depends on hitting a predictable blood level quickly, mention it specifically when you complete your consultation. Don't assume your prescriber already knows, list everything, including things taken only occasionally.

Step 2: the interactions that come up most often in clinical practice

Several categories deserve particular attention. Insulin and sulfonylureas (such as glibenclamide or glimepiride) are the most urgent: because Wegovy lowers blood glucose independently, combining it with these medicines raises the risk of hypoglycaemia. Your prescriber or diabetes team will usually reduce the insulin or sulfonylurea dose when Wegovy starts. Never adjust those doses yourself, that decision belongs with the clinician managing your diabetes.

Oral contraceptives are another area to flag. NHS guidance notes that semaglutide's gastric-slowing effect may reduce pill absorption, particularly in the early weeks of treatment, and our page covering whether semaglutide interacts with any medications explains how this applies across different drug types. Adding a non-oral method (such as condoms) while starting Wegovy is a sensible precaution; discuss it with your prescriber or GP before the first dose. For context, tirzepatide carries a more explicit instruction on this point, if you want to compare the two medicines' profiles, the semaglutide treatment page sets out how they differ.

Levothyroxine (thyroid replacement) is also worth mentioning to your prescriber, since its absorption is sensitive to changes in gastric conditions. Some anticoagulants, antiepileptics, and immunosuppressants with narrow therapeutic windows may also need closer monitoring, even if Wegovy's direct effect on them is modest. The NHS England wraparound care guidance covers this class-level absorption concern explicitly.

Step 3: alcohol, supplements, and over-the-counter medicines

People often overlook the things bought from a pharmacy shelf. Regular use of non-steroidal anti-inflammatory drugs (NSAIDs, ibuprofen, naproxen) can stress the stomach lining; combined with the GI side-effect profile of Wegovy, that may worsen nausea or discomfort, especially early on. It isn't a hard contraindication, but it's worth knowing.

Alcohol doesn't interact with semaglutide through a pharmacological pathway, but practically speaking, drinking while Wegovy is suppressing your appetite and slowing gastric motility can increase the effect of alcohol and raise nausea. Many people on Wegovy find their tolerance for alcohol changes, even when it's not something they expected.

Supplements (including high-dose vitamins, herbal preparations, and meal-replacement products) should also be listed. St John's Wort, for instance, affects the metabolism of several drugs and is relevant across a wide range of prescriptions, and our dedicated page on Wegovy medication interactions includes guidance on how these kinds of substances can affect your treatment. If you use it, say so. For a broader look at how the medicine works and what to expect, the Wegovy treatment overview covers the clinical picture in one place.

One thing our prescribers hear regularly: patients who list their prescription medicines carefully but forget to mention an iron supplement or a daily omega-3. Everything counts. That's the level of detail a safe consultation requires.

Step 4: what the clinical review at nume checks, and when to get medical help

Every consultation at nume is reviewed by a GPhC-registered Independent Prescriber, a real clinician reading your answers, not a screening algorithm. That review covers your current medicines, dose, frequency, and any conditions being managed, before any treatment decision is made. Transfer patients or those moving to a higher dose go through the same check at each stage. You can learn more about how our clinical team approaches this on the clinical team profile page.

Once on treatment, seek medical help promptly if you develop signs of hypoglycaemia (shakiness, sweating, confusion) if you're also on insulin or a sulfonylurea, or if you notice that a regular medicine seems less effective than usual. Severe, persistent stomach pain (especially if it reaches toward the back) is a separate signal to take seriously; the MHRA's January 2026 Drug Safety Update highlighted pancreatitis as a known infrequent but serious risk with GLP-1 medicines. Report unexpected side effects or any concerns about suspect products via the MHRA Yellow Card scheme.

Wegovy is a prescription-only medicine for good reason. Managing drug interactions is a clinical judgement, not something a checklist can fully substitute for. If you have questions about a specific combination, the safest place for those answers is a prescriber who can see your whole picture. Further detail on how Wegovy interacts with other medications and which medicines to avoid with semaglutide is covered across our related pages. To discuss your specific situation, speak to our prescribers via a free consultation, same-day clinical review, no waiting list.