Wegovy mL doses explained: reading the volume on your semaglutide pen

Step 1, understand the concentration: why mL and mg are not interchangeable

Wegovy solution comes at one concentration throughout the entire dose range: 2 mg of semaglutide per 1 mL of liquid. That figure is fixed by the manufacturer, Novo Nordisk, and approved by the MHRA. It means you can convert any prescribed dose to its mL equivalent by dividing by two: 0.5 mg is 0.25 mL, 1 mg is 0.5 mL, 1.7 mg is 0.85 mL, and so on. The reason this matters is that some people notice the injected volume varies as their dose increases through the titration schedule, and it can feel unexpected if you are not prepared for it. A slightly longer injection at 2.4 mg compared with the 0.25 mg starter is entirely normal and expected. The Wegovy overview page covers the full titration pathway if you want the broader picture alongside these volume figures.

What the pen does not show you is a graduated syringe, there is no mL scale to read. The device is pre-set at the pharmacy to deliver exactly the prescribed volume when you press the button. You confirm the right pen by the dose label (in mg), not by trying to estimate liquid depth.

Step 2, match the pen label to your prescription, not to a volume figure you found online

Each pen in the Wegovy range is labelled with its semaglutide strength in mg: 0.25 mg, 0.5 mg, 1 mg, 1.7 mg, and 2.4 mg for the standard maintenance pen. The MHRA approved a dedicated single-dose 7.2 mg pen in April 2026 for people who have reached the highest licensed dose under their prescriber's supervision, and if you want to understand how cartridge size relates to dose, the 3 mL semaglutide page explains what that volume looks like across different treatment stages. The the 1 mL semaglutide page explores what that volume means at different points in treatment. If the pen in your hand is labelled with a different mg figure from the one on your prescription, stop and contact your prescriber or pharmacist before injecting. Volume alone cannot tell you whether you have the right pen for your current stage of treatment.

The NHS patient information for semaglutide, published at nhs.uk/medicines/semaglutide, sets out how the pre-filled pen works and what to check before each injection. Reading it once, thoroughly, is genuinely worth the ten minutes.

Step 3, what the volume change tells you about how your dose is progressing

Titration up through the Wegovy schedule means the volume injected rises gradually. Most people move through the doses in approximately four-week steps: 0.25 mg for the first month, 0.5 mg for the second, 1 mg for the third, 1.7 mg for the fourth, and 2.4 mg from month five onwards as the standard maintenance dose. That last step from 1.7 mg to 2.4 mg is the largest single volume jump in the standard sequence, from 0.85 mL to 1.2 mL. For the majority of people it is barely noticeable; for some it coincides with a temporary uptick in nausea or injection-site awareness, which typically settles within a few days. The 2 mL semaglutide page explains what a 2 mL figure would represent in practice, which helps clarify why no standard Wegovy pen reaches that volume at 2 mg per mL concentration.

Your prescriber decides whether and when to progress, the titration schedule exists as a guide, not a conveyor belt. If side effects are difficult at a given dose, staying at that level for longer is a clinical decision, not a failure. A question our prescribers hear most weeks is whether a patient must move up on schedule; the honest answer is no.

Step 4, getting the injection right, and what arrives when you order through a registered pharmacy

The actual injection technique matters for consistent delivery of the stated volume. Wegovy is injected subcutaneously into the abdomen, thigh, or upper arm; rotating the site each week reduces localised skin changes. The pen is held at a 90-degree angle, the button pressed firmly and held for the count specified in the leaflet. Releasing early can mean the full volume is not delivered. If you see solution left in the pen after the injection window, do not re-inject, speak to your prescriber or pharmacist.

When a pen is dispensed through a GPhC-registered pharmacy and sent by DPD, it arrives refrigerated in a plain, unmarked box. The cold pack inside keeps the pen within the required 2–8°C storage range for the journey. You will get a tracking notification on your phone before it lands. From that point, the pen lives in your fridge until use, check the Patient Information Leaflet for the room-temperature window allowed once you remove it, as that figure is specific to the product and can change between formulations. For questions about where to source Wegovy safely, the registered-pharmacy route is the only legal option in the UK. The weight-loss treatment overview outlines what a regulated private prescription pathway looks like from consultation through to delivery.

If you have questions about a specific dose or volume your pen is showing and you are already a patient, the contact page connects you with the aftercare team. If you are still weighing up treatment options and want a clinical view, the place to start is a free consultation at the treatment page.