What colour is semaglutide — and what does it actually tell you?

The biggest myth: tinted solution means a different strength

Search forums long enough and you will find posts claiming that semaglutide pens contain blue, yellow or faintly pink liquid depending on the dose. This is not accurate. The injectable semaglutide in every Wegovy pen (from the 0.25 mg starting pen through to the 2.4 mg maintenance dose) contains a clear, colourless aqueous solution. Strength is indicated on the label and by the colour-coded cap that Novo Nordisk uses to differentiate pens in the titration sequence, not by the colour of the medicine inside.

This matters because patients inspecting a pen for the first time sometimes worry that a completely clear liquid cannot possibly be doing anything. It can. The active ingredient, semaglutide, is dissolved at concentrations too low to produce visible colour. Clear liquid is correct. If the liquid looks cloudy, has visible particles or has taken on any colour at all, the pen should not be used, that guidance comes directly from the patient information leaflet, which is always the reference point for what you are looking at.

The colour-coding on Wegovy pens is a packaging and safety feature, not a property of the drug itself. Confusing the two is an easy mistake, but an important one to untangle before you start treatment.

Storage, temperature and why colour can change, and what to do

Semaglutide solution can change appearance if it has been stored incorrectly. The main risks are heat exposure and freezing. A pen that has been left in direct sunlight, kept in a hot car or accidentally frozen may no longer look or behave as intended. Any visible cloudiness or discolouration after a storage mishap is sufficient reason to discard the pen and contact your prescriber or pharmacy.

Correct storage is refrigerated, between 2°C and 8°C, away from the freezer compartment. Novo Nordisk's patient information leaflet also gives a limited room-temperature window for pens already in use, the exact duration and temperature ceiling are published in that leaflet and on the electronic Medicines Compendium (eMC), which holds the full Wegovy Summary of Product Characteristics. Our prescribers are asked about storage fairly often; the short rule is: fridge, not frozen, away from light.

If you are unsure whether a pen has been compromised, erring on the side of discarding it is the safer call. Using a pen that has been stored outside the recommended range risks getting an incomplete or ineffective dose, not just a cosmetic issue. Questions about a specific pen you hold are best directed to your dispensing pharmacy or prescriber rather than answered at arm's length.

Changes in how a pen looks after storage problems are also one reason sourcing semaglutide from a verified, regulated pharmacy matters, cold-chain integrity is something a GPhC-registered pharmacy maintains as a matter of licence compliance, and something informal sellers cannot guarantee.

Oral semaglutide: a completely different form, a completely different appearance

Since June 2026, semaglutide is also available as a daily tablet, Wegovy tablets, approved by the MHRA as the first oral GLP-1 medicine licensed for weight management in the UK. The tablet is a film-coated solid, taken first thing in the morning with a small amount of plain water before any food or other drink. It does not resemble the injection solution at all.

The oral form is relevant to colour questions because some readers asking what colour semaglutide is are actually trying to work out whether a tablet or a liquid is right for them. That is a clinical question, and a prescriber works through it with you as part of a proper consultation. What can be said factually here: the injectable solution is clear, the tablet is a solid, and neither carries colour as a meaningful indicator of dose or quality beyond the packaging conventions already described.

You can read a fuller breakdown of what semaglutide is and how it works if you want the pharmacology rather than the appearance. For those curious about related combinations such as semaglutide with B12 (a formulation that appears in some compounded products) that is a separate topic entirely; those are not UK-licensed products, and the NHS's guidance at NHS.uk's semaglutide page covers only licensed preparations.

What to check before using your pen

Before each injection, a brief visual inspection takes less than ten seconds and is worth doing every time. Hold the pen up to a light source. The liquid should be clear. There should be no floating particles, no cloudiness and no discolouration. The pen should not have been frozen. The expiry date on the label should not have passed. If any of those checks fails, do not inject. Contact your pharmacy.

These checks apply regardless of which strength you are using. If you have recently had a dose increase and the new pen looks identical to the previous one (because it will) that is expected and correct. It can feel strange, especially when you are conditioned to expect colour-coded difference. Trust the label. The Wegovy treatment overview on our site gives broader context on the titration schedule and what to expect at each stage.

If you are at the point of thinking about starting treatment, or if you are transferring from another provider, our prescribers review each consultation personally, not via automated decision-making. A note on what changes at each dose and how to handle missed or delayed injections, such as whether the time of day you inject matters, forms part of the clinical conversation. When you are ready, speak to our prescribers and take it from there.