How Much Semaglutide Is in Each Wegovy Pen — and What That Means in Practice

Step 1 (understanding what the pen physically contains

When your Wegovy pen arrives) tracked by DPD in plain, unbranded packaging, what you are opening is a pre-filled injector holding a solution of semaglutide ready to use. There is one pen per month of treatment, and it contains four doses at a single fixed concentration. You do not see a volume measurement on the barrel the way you might with an old-fashioned syringe; instead the pen is engineered to release the correct amount each time you press it.

The strengths available in the UK are 0.25 mg, 0.5 mg, 1.0 mg, 1.7 mg and 2.4 mg per weekly injection, each supplied as its own dedicated pen. A sixth option (a 7.2 mg single-dose pen with a built-in covered needle that locks after use) was approved by the MHRA on 14 April 2026 for adults with obesity (BMI 30 or above). Each of these is a distinct device; you receive whichever one your prescriber has determined is right for your current point in treatment. If you want to look at how volume and concentration relate across the range, the pen's liquid volume by strength is covered in more detail separately.

Storage matters from the moment it arrives. Wegovy pens should be kept refrigerated between 2 and 8°C; the exact room-temperature window for a pen you are actively using is set out in the Patient Information Leaflet inside the box. Always follow that, not third-party estimates. The NHS semaglutide medicines page also summarises storage guidance clearly.

Step 2, how the titration sequence determines which amount you receive

The Wegovy prescribing schedule starts at 0.25 mg weekly. This is not the therapeutic dose; it is a period of adjustment that gives your digestive system time to settle before the medicine reaches the levels associated with meaningful weight change. From there, prescribers typically step up through 0.5 mg, 1.0 mg and 1.7 mg before reaching 2.4 mg, spending roughly four weeks at each level. The 7.2 mg pen sits above this as the current maximum maintenance dose.

What this means practically is that the amount of semaglutide in the pen you hold right now reflects your clinical history, not just a catalogue choice. A person starting treatment gets a 0.25 mg pen; someone who has tolerated four weeks at 1.7 mg gets the 2.4 mg pen next, subject to prescriber review. At nume, every repeat order is clinically re-assessed before dispensing, there are no automatic renewals, and dose increases require your prescriber to be satisfied you have tolerated the previous level. The broader picture of what one complete Wegovy pen means across its four-week lifespan is worth reading if you want the full context: what one Wegovy pen covers walks through that.

People already established on the 2.4 mg weekly injection may, subject to clinical assessment, move to the 25 mg oral Wegovy tablet rather than stepping to 7.2 mg, though that is an entirely separate formulation and a decision for your prescriber. The two routes are not interchangeable without guidance.

Step 3, what actually happens at each injection and how the amount is delivered

The mechanics are straightforward. You attach a new needle, check the flow, select an injection site (abdomen, thigh or upper arm, rotated each week), and press the plunger until it stops. The pen delivers the full pre-set dose automatically. There is no dial to set, no liquid to measure and no way to accidentally administer a larger or smaller amount than the pen is designed for. A step-by-step guide to the injection technique covers posture, site rotation and needle change in full.

One thing our prescribers hear regularly: patients wondering whether a faster or slower press changes the dose. It does not. The amount is fixed in the device. What does matter is making sure the plunger has fully depressed before you withdraw the pen, stopping early is the one way a partial dose can occur, and the leaflet's technique guidance covers this clearly.

On the subject of needles: Wegovy pens use compatible pen needles, which must be changed for every injection. Used needles go into a sharps bin immediately; if you do not have one, a 1-litre sharps container is available from our pharmacy.

The click-count question comes up often too. Some patients count audible clicks to judge whether the dose has been delivered. For detail on how clicks correspond to dose delivery on Wegovy devices, the Wegovy click-count guide answers that precisely. And if you want a broader overview of the pen formats Wegovy uses across the range, our Wegovy pen overview is a good starting point.

What this means if you are considering starting treatment

Wegovy is licensed in the UK for adults with a BMI of 30 or above, or 27 to 29.9 with at least one weight-related health condition. Lower thresholds apply for some ethnic backgrounds under UK clinical guidance. A prescriber assesses the full picture (medical history, current medicines, and whether the titration schedule is appropriate for you) before any pen is dispensed.

Clinical trial data published in the New England Journal of Medicine (the STEP 1 study) found an average weight reduction of around 15% over 68 weeks at the 2.4 mg maintenance dose. The 7.2 mg data reported approximately 20.7% average loss over 72 weeks. These are trial averages; individual outcomes vary and depend on diet, activity and consistency of use alongside the medicine. For a wider look at the semaglutide treatment options available through regulated UK routes, our Wegovy overview sets the full context.

If you are weighing up whether semaglutide or another licensed option suits your situation, the treatment overview explains what is available and how the clinical assessment works. When you are ready to speak to a prescriber, checking your eligibility is the place to start, consultations at nume are free, reviewed the same day by a GPhC-registered Independent Prescriber, and carry no obligation.