Wegovy interactions: medicines to raise with your prescriber

Insulin and sulfonylureas

The most common practical problem is low blood glucose when you take Wegovy with insulin or a sulfonylurea. Your prescriber may lower those doses and ask you to check your glucose more often. The size of the change depends on your readings, how much you eat and your diabetes history.

Do not stop insulin because Wegovy also lowers glucose. Semaglutide does not replace insulin. Tell your diabetes team about any private weight-management prescription. Both services then work from the same medicine list.

Never double up on GLP-1 treatment

Do not combine Wegovy injection with oral Wegovy, Ozempic, Rybelsus or another GLP-1-based medicine on your own. You risk taking the same drug twice at an unknown total dose. Any switch needs a clear plan with a last-dose date and a first-dose date.

Different brand names can hide the same active ingredient. Look for semaglutide on the label. Tell your prescriber about samples, spare pens or tablets bought elsewhere. Do not use leftover medicine to cover a gap in supply without advice.

Tablets, stomach emptying and sickness

Semaglutide slows how fast your stomach empties. This does not make every tablet stop working, and you do not need a fixed gap of so many hours between doses. Interaction studies and the information for each product guide the decision. Moving all your tablets to a different time of day may not fix the real problem.

Vomiting or severe diarrhoea affects absorption on its own. If you take a time-critical medicine, ask your pharmacist what to do if you are sick after swallowing it. The answer differs from product to product. Taking another dose without checking is sometimes harmful.

Warfarin and other anticoagulants

If you take warfarin or another coumarin anticoagulant, UK product information recommends more frequent INR checks when you start semaglutide. Changes in diet, weight and illness also affect INR. Tell your anticoagulation clinic about the new treatment before you start, so a surprise INR result does not catch anyone out.

Medicines affected by changes in your health

As your weight, blood pressure or glucose falls, a long-standing prescription may become less suitable, even with no direct chemical interaction. Dizziness, repeated hypos or dehydration all call for a review. Do not cut every long-term medicine yourself because you have lost weight.

Mention supplements, laxatives, anti-sickness products and painkillers too. Some symptom treatments add to constipation, drowsiness or kidney risk. Keep an up-to-date list with each dose and the reason you take it, and share the list with your GP, pharmacy and private prescriber. Ask who will coordinate changes. A safe combination depends on follow-up as well as the first interaction check.