Brown Wegovy pen: what the colour tells you and how to act on it

Why your first pen is brown, and what that means for your first four weeks

Starting at 0.25 mg is a deliberate clinical choice, not a tentative half-measure. The body needs time to adjust to semaglutide, and the initial dose is calibrated to minimise the nausea, bloating and digestive discomfort that are most likely to appear when GLP-1 activity increases suddenly. Think of it as giving your system a controlled introduction rather than a full-dose debut.

Novo Nordisk colour-codes each Wegovy strength so that patients and clinicians can identify pens at a glance. Brown carries the 0.25 mg dose. After roughly four weeks on this strength, a prescriber will typically move you to the next step, but that call belongs to the prescriber, not to the calendar. If side effects are still pronounced at the end of week four, staying at 0.25 mg for another month is a legitimate and often sensible option. The Wegovy pen guide on our site covers the full colour sequence across the titration pathway.

One practical note: the dose marker printed on the pen label is the figure to trust. The colour is a helpful quick-check, but always read the label before injecting, especially if you store multiple pens or have recently received a repeat supply at a different strength. If you have questions about what comes in a single starter supply, our guide to the Wegovy 1 pen explains exactly what is included and what to expect when your first pen arrives.

How to inject from the brown pen, the decision that trips most people up

The mechanics of the pen itself are the same regardless of the colour. You will need to attach a new needle, choose an injection site (abdomen, front of the thigh, or upper outer arm), clean the skin with an alcohol swab, and follow the steps in the Patient Information Leaflet precisely. The NHS patient-level guidance on semaglutide provides a clear overview of injection technique and what to watch for afterwards, and it is worth reading before your very first dose rather than skimming it mid-injection.

Rotating injection sites matters from the brown pen onwards. Repeatedly using the same spot can cause localised skin changes that affect how the medicine is absorbed. Abdomen, thigh and upper arm are each valid; moving around them systematically is the standard recommendation.

Used needles go into a dedicated sharps container immediately after injection, not the household bin. A 1-litre sharps container keeps disposal legal and safe at home. Your local council or pharmacy can advise on collection arrangements.

If the pen feels stiff, the plunger does not depress smoothly, or the window shows anything other than the expected clear or almost-colourless solution, do not use it. What to do if your Wegovy pen seems faulty is covered in a dedicated guide.

Side effects to expect from the 0.25 mg dose, and the point at which you should seek help

Gastrointestinal effects are common at every strength but tend to peak during the first few weeks as the body adjusts to each new dose level. On the brown 0.25 mg pen, most people experience mild-to-moderate nausea, occasional loose stools, or a reduced appetite that can feel slightly abrupt. These typically ease within days to two weeks. Staying well hydrated, eating smaller portions slowly, and avoiding very fatty or heavily spiced meals during the adjustment period all help.

The NHS medicines page for semaglutide sets out the full side-effect profile, it is the clearest patient-facing summary of what is common versus rare, and worth bookmarking.

Seek medical help promptly if you develop severe stomach pain that radiates towards your back, with or without vomiting. That pattern can indicate acute pancreatitis, which the MHRA flagged in a January 2026 Drug Safety Update as an infrequent but serious risk with GLP-1 medicines. It is not something to manage at home or wait out. You can report any suspected side effects through the MHRA's Yellow Card scheme. Other signs that warrant prompt attention include symptoms of a serious allergic reaction, or severe dehydration from persistent vomiting or diarrhoea.

Most people tolerate the brown pen well. The design of the titration schedule, starting low and stepping up gradually, is precisely what keeps the side-effect burden manageable for the majority of patients.

Moving from brown to the next strength, and what the decision involves

After four to eight weeks on the 0.25 mg dose, the question of progression will come up. The standard pathway moves to 0.5 mg next, then 1.0 mg, 1.7 mg, and finally the 2.4 mg maintenance dose, though not everyone reaches or needs the highest strength. A prescriber reviews tolerance and response before any step change. If you are mid-titration and considering whether you are on the right track, the weight-loss treatment overview gives helpful context on what the evidence shows across the full schedule.

On the cost side, each strength is priced per pen, and the total monthly cost varies as you move through the programme. If cost is a live concern at this stage, the buying guide for Wegovy covers what to look for in a provider and how pricing is typically structured, payday falling mid-titration or a holiday overlapping your next order date can catch people out, so it is worth planning a repeat request before the pen runs out rather than after.

Wegovy is a prescription-only medicine requiring clinical assessment at every repeat. A prescriber will not simply issue the next strength automatically; your response, tolerance and any new information about your health all feed into that review. That is not a bureaucratic hurdle, it is the mechanism that keeps titration safe. If you are thinking about starting, our full guide to Wegovy weight-loss injections covers how the treatment works and what to discuss with a prescriber before your first dose, and our prescribers at the consultation page can assess whether Wegovy is the right fit for your circumstances.