That yellow bar on your Wegovy pen — here's what it's telling you

You've just injected and the yellow bar is still there, did it work?

You pressed the button, held the pen against your skin for the full count, and pulled it away. Then you glance at the window. The yellow bar is still showing. Panic is understandable, but this is one of the most common questions people have in the first few weeks of treatment.

The short answer: a partially visible yellow bar after injection is normal. The pen is designed so the bar drops progressively as the medicine is delivered, but it doesn't vanish the moment you release the button. What you're looking for is whether the bar has moved downward compared with where it sat before you injected. If you're on an early dose and the pen still has remaining doses left in it, you'll see yellow because there's semaglutide still in the reservoir, that's by design.

The Wegovy pen is a multi-dose device for some of the lower titration steps, so the window reflects total fill across uses. The NHS semaglutide medicines page explains how to use the pen correctly, and the Patient Information Leaflet packaged with your pen gives the full step-by-step guidance. Always read it before your first injection. If the bar genuinely hasn't moved at all and the injection counter on the pen hasn't changed, the dose may not have been delivered, and you should contact your prescriber.

Yellow bar at the bottom: what to do when your pen runs out

An empty pen (yellow bar at or below the fill line, injection counter showing the last dose used) means you've completed what that pen was prescribed to deliver. This is the normal end of a supply cycle, not an emergency.

What it means practically is that you need to arrange your next pen before you reach this point, not after. Running out mid-cycle is easy to avoid with a little forward planning. Orders placed with our Wegovy service by 12pm on a working day are reviewed the same day and, once a prescriber approves the repeat, dispatched for free next-working-day DPD delivery. A Monday morning order typically arrives Tuesday, worth bearing in mind around bank holidays, when the working-day count shifts by a day or two, or if a payday lands just before you'd normally reorder.

Dispose of the finished pen in a sharps container, never in a household bin. Your prescriber will tell you how to source one locally, or a pharmacist can advise. Do not attempt to refill or reuse the pen; it is single-patient use only.

When a yellow bar problem signals something that needs attention

Most yellow-bar queries are simple reading questions. A handful aren't. Contact your prescriber or a pharmacist if you notice any of these with your pen: the bar hasn't moved after an injection and the counter is unchanged; there is visible damage to the pen, cloudiness in the medicine, or particulate matter in the window; the pen feels different to press compared with previous doses; or you're uncertain whether a dose was delivered and you're due another in a few days.

On the medicine side, certain side effects should also prompt a call rather than a wait-and-see approach. The MHRA's Yellow Card scheme allows patients to report suspected side effects directly; it exists for situations where something feels wrong and you're not sure where to take it. Severe stomach pain that radiates to the back, persistent vomiting, or signs of an allergic reaction are reasons to seek medical help promptly, not to manage at home. The common questions our team fields also cover what to do if you miss a dose, a prescriber or the leaflet in your pack is the right guide for timing decisions, not an online forum.

If you're experiencing unexplained tiredness or low energy on Wegovy, or you feel your progress has plateaued, those are separate conversations worth having with your clinical team too, and our guidance on slow weight loss with Wegovy can help you understand what counts as a plateau and what to do about it.

Getting your next supply and the clinical review behind it

Every repeat supply of Wegovy from nume comes with a fresh clinical assessment, not an automatic re-send. A real prescriber reads your update (your current weight, any side effects, how the last pen felt) before approving the next. This matters especially at dose-increase stages, where the review confirms you're ready to move up the titration schedule.

The cost of treatment varies by dose and by provider. For context on how UK private Wegovy pricing works and what a transparent price should include, the guide to where to buy Wegovy in the UK covers the landscape honestly. The short version: a legitimate price includes the clinical assessment and prescription, not just the pen itself. If you're earlier in the process and still comparing options, the semaglutide overview sets out what the medicine is, how it works, and what the trial evidence actually shows, and if you're specifically considering a compounded or branded alternative, our page on Flow semaglutide explains how that option works and who it might suit.

When you're ready to take the next step, our prescribers review consultations the same day. Speak to our prescribers to begin or continue your treatment.