Wegovy colours: what the pen markings mean and what the solution should look like

How Novo Nordisk uses colour to distinguish Wegovy pen strengths

Novo Nordisk designed the Wegovy pre-filled pen range with colour-differentiated labels and plunger caps so that patients can identify dose strengths at a glance. The titration pathway for Wegovy injection runs from 0.25 mg (the starting dose) through 0.5 mg, 1.0 mg and 1.7 mg, up to the 2.4 mg maintenance dose, and, following MHRA approval of a higher dose in January 2026, to 7.2 mg for eligible patients. Each step in that ladder uses a visually distinct pen design. The exact colour names used on packaging can vary slightly between production batches and between the UK and other markets, which is a common source of confusion online; what matters clinically is matching the label's stated milligram strength to your prescribed dose, not matching a specific shade to a name you have read on a forum.

A question our prescribers hear most weeks is whether a pen looks "right", patients who have seen images of Wegovy pens from other countries sometimes notice the colour appears slightly different to their own. This is normal: Novo Nordisk's labelling design has evolved across markets and across the different pen generations, including the newer single-dose 7.2 mg pen approved by the MHRA on 14 April 2026. The label's printed dose strength in milligrams is always the definitive reference. For a wider look at the medicine's properties, including what the solution colour signals about stability, our page on what colour semaglutide solution should be goes into more depth, and if you are using a formulation that combines semaglutide with B12, our guide to what colour semaglutide with B12 should appear covers how that combination can look different.

The Wegovy SmPC, published on the electronic Medicines Compendium, specifies that the solution for injection should be clear and colourless to slightly yellow. Anything outside that (cloudiness, a precipitate, particles in suspension) means the pen should not be used. Store Wegovy pens in the refrigerator at 2–8 °C; the SmPC sets out the exact room-temperature window if refrigeration is temporarily unavailable, and that document is the right place to check rather than any third-party source. NHS guidance on semaglutide also covers storage and what to do if a dose is missed.

What a discoloured pen or solution actually means for safety

The semaglutide solution is a biological medicine. Discolouration beyond pale yellow, visible particles, or a cloudy appearance can indicate degradation, most commonly from exposure to temperatures outside the recommended range, from freezing, or from a pen that has been stored incorrectly at some point in the supply chain. This is one reason why purchasing weight-loss medicines from unverified online sellers carries real physical risk: the MHRA has warned publicly that fake pens and improperly stored genuine pens have caused harm. Counterfeit pens seized in the UK have in some cases contained entirely different substances. Pen colour-coding cannot protect you from a counterfeit, only buying through a GPhC-registered pharmacy using the licensed UK supply chain does that.

If the pen you receive looks correct by dose label and colour but the solution itself appears cloudy or off, do not inject it. Contact your prescriber or the pharmacy that dispensed it straight away. Report any suspect product via the MHRA Yellow Card scheme, which also accepts reports of suspected counterfeit medicines. For anything connected to how Wegovy affects your body (including some of the more unexpected physical changes patients notice during treatment) our page on feeling cold on Wegovy explains one of the less-discussed side effects, and Wegovy and urine colour addresses another question that comes up regularly.

Putting pen colour in context: what it does not tell you about dosing

Colour-coding is a packaging safety feature, not a clinical instruction. It tells you what strength of semaglutide is in the device; it does not tell you whether that strength is the right one for you at this point in your treatment. Dose increases are a clinical decision made by a prescriber after reviewing how you have tolerated the current dose, your weight trajectory, and any side effects you have reported. The titration schedule for Wegovy (moving up approximately every four weeks through the dose steps) is set by your prescriber, not by the pen you happen to have in your hand.

This matters practically because the dose-increase schedule and the full Wegovy treatment overview are governed by NICE guidance and the licensed SmPC. NICE's appraisal of semaglutide for weight management (TA875) specifies that treatment should be delivered alongside structured lifestyle support; the medicine is an adjunct to, not a replacement for, dietary change and activity. Eligibility for treatment and the right maintenance dose both depend on your clinical picture. If you are considering starting Wegovy or moving to a higher dose, the appropriate route is a clinical consultation, start your free consultation with our prescribers to have your options properly reviewed. You can also read through our frequently asked questions if there are other aspects of treatment you want to understand before you begin, or visit the about-us page to learn more about how our service works.