Wegovy PI: What the Patient Information Leaflet Covers and What It Means

The biggest misconception: the PI is not a prescription or a guide to self-managing your dose

Most questions about the Wegovy patient information leaflet come from people who have read it and concluded it tells them how to titrate themselves. It doesn't. The PI describes the licensed schedule (0.25 mg for four weeks, then 0.5 mg, then 1.0 mg, then 1.7 mg, then 2.4 mg) so you know what to expect. Your prescriber decides the pace, and whether to hold a dose rather than increase it, based on how you're tolerating treatment. The leaflet is written to support, not replace, that conversation.

A related misreading: some patients take the PI's side-effect list as a forecast of what they will definitely experience. It's a list of what has been reported across clinical trials and post-marketing surveillance, not a personal prediction. Many people progress through the entire titration with only mild, short-lived nausea after the first couple of injections. Others find certain doses harder. The PI arms you with the right vocabulary to tell a clinician what you're noticing; it doesn't score your experience in advance.

The full PI for the current Wegovy pen is published on the Medicines.org.uk electronic Medicines Compendium (eMC), this is the live, MHRA-approved version and should be your first stop if you've mislaid the paper copy or want to check the precise wording before your next dose.

Storage and handling: where the PI is most precise, and most often ignored

The storage section of the Wegovy PI is one of the parts people most commonly skim past, and it matters more than most realise. Semaglutide is a biological medicine; the pen must be kept refrigerated between 2°C and 8°C until first use. After that, it can be kept at room temperature or refrigerated for a defined window, the exact duration is stated in your leaflet and can vary between pen formats, which is why the PI, not a general article, is the reference you need.

Pens must be protected from light. They should never be frozen, a pen that has been frozen should not be used. When you're travelling (bank holidays, a long weekend away, a summer trip), it's worth planning your storage ahead of time rather than assuming a cool bag will suffice. The PI gives the specific temperature range; if you're ever unsure whether a pen has been compromised, contact your prescriber or pharmacist before injecting.

The leaflet also covers injection technique in detail: approved sites are the abdomen, the thigh, and the upper arm; you rotate sites each week; the pen should not be injected into skin that is bruised, inflamed or has scar tissue. These instructions exist because consistent technique affects both comfort and absorption. The full Wegovy overview on this site covers pen handling in plain language if you want a companion read.

What the PI says about side effects, and the one signal that needs urgent attention

The Wegovy PI organises side effects by frequency: very common, common, uncommon and rare. The very common ones are gastrointestinal, nausea tops the list, followed by diarrhoea, vomiting, constipation, and stomach pain. Fatigue, dizziness, headache and injection-site reactions appear in the common category. Most of these settle as your body adjusts, particularly after each dose step.

One side effect deserves more than a skim. The PI flags acute pancreatitis as a condition to be aware of: severe, persistent abdominal pain, especially pain that radiates through to the back, with or without vomiting, is a reason to stop the injection and seek medical help the same day. This is consistent with the MHRA's guidance on reporting side effects via the Yellow Card scheme, which specifically covered GLP-1 medicines in a Drug Safety Update in January 2026. If in doubt, seek help; don't wait for the next scheduled call with your prescriber.

The PI also notes that oral medicines taken at the same time as semaglutide injections may be absorbed more slowly, because the medicine slows gastric emptying. If you take oral contraceptives, the leaflet and NHS England's guidance on weight-management injections both recommend discussing whether an additional method of contraception is appropriate, your prescriber will cover this at assessment.

Who the PI says is not suitable, and why a prescriber review catches what self-reading can't

The contraindications section of the Wegovy PI is precise and unambiguous. Semaglutide is not recommended during pregnancy, while breastfeeding, or if you are trying to conceive. It is not licensed for anyone under 18. A personal or family history of medullary thyroid carcinoma, or of Multiple Endocrine Neoplasia type 2 (MEN2), rules it out entirely. Severe kidney disease and certain inflammatory bowel conditions are listed as situations requiring close discussion.

Reading this section yourself is useful. But reading it is not the same as a clinical assessment. A GPhC-registered prescriber works through your medical history, your current medicines, your weight and your goals in a structured way that a leaflet cannot replicate. At nume, that review is carried out by a real prescriber (you can read about the clinical team's approach on the clinical team page) not by an automated system, and it happens on the same day you submit your consultation.

If you're looking at the PI to work out whether you'd be eligible, the patient information and licensing detail page covers eligibility criteria in more depth alongside the licensed indication. If you want to understand more about how the titration works in practice, our pages on the autoinjector pen and how it's supplied and the first maintenance dose and second maintenance dose cover each stage in plain language. For a broader look at where Wegovy sits alongside other options, the weight-loss treatment overview is a good starting point. And if cost is part of your thinking, the Wegovy price comparison page sets out what UK private treatment typically costs and what a legitimate price should include.

The consultation at nume is free. Once a prescriber has reviewed your information and approved treatment, the medicine is dispatched the same day (for orders submitted before 12pm, Monday to Friday) and delivered free the next working day by DPD in plain packaging. If you're ready to go through your own medical history with a prescriber and get a considered clinical view, start your free consultation here.