What the Wegovy green pen is and whether it's right for you

The decision in front of you: which pen, which dose, and does colour alone tell you enough?

If you've been prescribed Wegovy and your pharmacist has handed you a green pen, the colour is a useful at-a-glance signal — but it isn't the whole picture. Novo Nordisk uses colour coding across the Wegovy pen range to help patients quickly distinguish dose strengths during the slow titration process that runs from 0.25 mg all the way through to the 2.4 mg maintenance dose. The green pen corresponds to one of the lower steps in that ladder, and if you want to understand exactly what the Wegovy 1 pen contains and when it is used, that detail is worth checking before your first injection. The most important check, every single time, is to read the dose printed on the label itself. Colour is a support; the label is the authority.

The titration schedule exists for a reason. Semaglutide's side-effect profile is heavily GI-led (nausea, loose stools, burping, and a general unsettled stomach are common when the dose increases) and moving up slowly keeps most of those symptoms mild and short-lived. Rushing or skipping steps is a clinical decision that belongs with your prescriber, not one to make on your own. If you're unsure where your current pen sits in the sequence, the Wegovy pen overview sets out the full colour-coded range in plain terms.

It's easy to feel a little anxious the first time you hold one of these pens. That's completely normal, and our prescribers hear it regularly. The device itself is designed to be straightforward, and the technique becomes routine quickly.

How the Wegovy green pen is used in practice

The pen is pre-filled and pre-set; there's no dial to turn and no dose to draw up. You choose an injection site (the abdomen, the front of the thigh, or the outer upper arm all work) clean the skin, remove the cap, press the pen against the site, and activate the injection. The full step-by-step guide to using a Wegovy pen covers technique in detail, including how to rotate sites across weeks to avoid localised reactions.

A few practical notes worth having before your first injection. Never inject into skin that is sore, bruised, or has a rash. Patients sometimes also ask about how many ml a Wegovy pen holds, which can help you confirm you have received the correct device before you begin. Each pen is single-use; after injection, place the used device into a suitable sharps container rather than a household bin. Your GP or local pharmacy can advise on sharps disposal in your area.

The NHS patient information for semaglutide is worth bookmarking; it covers what to do if you miss a dose, how to store the pen, and which symptoms warrant a call to your GP. Side effects to watch include any severe or persistent stomach pain that travels to your back — that pattern needs same-day medical attention because it can signal pancreatitis, a known but uncommon risk with GLP-1 medicines. Report any suspected side effects through the MHRA Yellow Card scheme.

What the colour-coding doesn't tell you about your treatment

One thing patients sometimes assume: that reaching the maintenance dose is the end point they should rush toward. It isn't. The green pen's lower dose is doing real work, settling your system, giving your prescriber a baseline reading of how your body responds, and building a foundation for the months ahead. If you have been given a Wegovy 1 ml pen, our page on that specific device explains what the volume figure means alongside the dose strength printed on the label. Weight loss in the early weeks is rarely the headline figure; the evidence comes from the full trial duration.

Those headline figures are genuinely meaningful. The STEP 1 trial, published in the New England Journal of Medicine, reported an average body-weight reduction of around 15 % over 68 weeks at the 2.4 mg maintenance dose. More recently, the MHRA approved a higher 7.2 mg dose for adults with a BMI of 30 or above, with 72-week trial data showing average losses approaching 21 %. Where you start in this journey (green pen or otherwise) matters far less than consistent clinical oversight throughout. For context on how Wegovy fits alongside other licensed weight-management options, the weight-loss treatment overview is a good starting point.

Cost is a practical consideration too. Wegovy is a private prescription in most cases right now; for a grounded look at what treatment pricing actually involves, the Wegovy cost and access guide walks through what a legitimate price covers and what it doesn't. It's the one place on this site that addresses the money question directly.

When prescription and clinical review come into the picture

Wegovy is a prescription-only medicine. A prescriber who has reviewed your full health picture determines which pen you start on, when you move up, and whether treatment remains appropriate at each review. That applies whether you access Wegovy through a specialist NHS weight management service or through a regulated private route such as our pharmacy.

At nume, every consultation is read by a GPhC-registered prescriber on the same day, a real clinician, not automated software. If you're thinking about starting treatment or have questions about the pen you've been sent, starting a free consultation is the straightforward next step. Our clinical team, led by our independent prescriber, reviews each case individually before any prescription is issued.