The semaglutide 4mg pen in the Wegovy titration schedule

Where 4mg sits in the official Wegovy titration pathway

The Wegovy schedule published on the NHS semaglutide medicines page works in monthly steps: 0.25mg for four weeks, then 0.5mg, then 1mg, then 1.7mg, and finally 2.4mg as the standard maintenance dose. The 4mg figure refers to the total semaglutide content of one multi-dose pen (four weekly 1mg injections) rather than the amount given in a single injection. Knowing that distinction matters, because a box label that reads "4 mg" can look confusing the first time you open it.

At the 1mg weekly dose, most people have passed the point where nausea is at its sharpest. That said, GI symptoms can reappear after any upward move, and it is worth watching how you feel in the first week or two after switching pens. If discomfort is persistent or severe, your prescriber needs to know before the next titration step is considered. Details on what to expect at each stage are covered in the guide to injecting semaglutide.

The titration sequence exists because the STEP programme established that slower dose escalation reduces dropout from side effects. Rushing through the lower doses to reach 2.4mg faster is not something to attempt independently, the schedule is set by your prescriber for clinical reasons, and any changes should come from them.

What the trial evidence tells us about the dose-response relationship

The STEP 1 trial, published in the New England Journal of Medicine, enrolled 1,961 adults with obesity or overweight and at least one weight-related condition. Over 68 weeks, participants receiving semaglutide 2.4mg alongside lifestyle support lost an average of around 15% of their body weight. That figure belongs to the maintenance dose, the 4mg pen represents the build toward it.

What the trial design also shows is that adherence through the titration phase matters. Participants who completed the full escalation and stayed on maintenance dose achieved substantially better outcomes than those who dropped out or stayed at lower doses. This is one reason prescribers take the titration steps seriously rather than treating them as a formality.

For those thinking about cost alongside clinical progress, our Wegovy cost page explains how private treatment is typically priced and what a transparent all-in price should include.

Practical things to check before you inject from the 4mg pen

One habit that takes under a minute and is worth making routine: before each injection, hold the pen up to the light and check that the liquid is clear and colourless with no particles. Any cloudiness or discolouration means the pen should not be used, contact your prescriber and the pharmacy. This is straightforward with Wegovy's clear-window pens and takes seconds.

Beyond that visual check, storage matters. The 4mg pen should be kept refrigerated between 2°C and 8°C. There is a limited window during which it can be stored at room temperature, but the Patient Information Leaflet (included in your pack and available on the eMC) gives the exact timeframe; always defer to that rather than any general figure online.

Injection technique at this dose is no different from earlier pens. Sites can be the abdomen, outer thigh or upper arm, and rotating between them reduces the chance of skin reactions building up. If you have questions about technique, the semaglutide injection overview goes through the process step by step. A fresh needle per injection is important; replacement needles are available if you need to restock.

Moving from 4mg to the next step, and who decides

The prescriber, not the patient, decides when to move up. At a clinical review, they will typically ask about tolerability, any side effects, and whether you are managing the lifestyle changes that sit alongside treatment. If things are going well, the next pen in the sequence follows roughly four weeks later. If GI symptoms have been significant, they may recommend staying at 1mg weekly for longer before progressing.

People sometimes ask whether the 4mg pen is the same as a dose used in diabetes treatment. Ozempic also contains semaglutide, but it is licensed for type 2 diabetes, not weight management, the two products are not interchangeable, and Ozempic should never be sought as a substitute for Wegovy. Your prescriber will always be working from the Wegovy licence when reviewing your weight-management treatment.

If you are considering Wegovy as a weight-loss treatment and want to understand whether it might be appropriate for you, a free consultation with one of our GPhC-registered prescribers is the right starting point. They review every consultation personally, a real clinician reads your answers the same day. Start your free consultation and get a clinical assessment that is built around your circumstances.