How Often Do You Inject Wegovy, and What Happens If You Miss a Dose?

Why once a week, and does the day actually matter?

The decision about how often to inject Wegovy has already been made by the medicine's design. Semaglutide has a half-life of approximately one week in the body, which is precisely why Novo Nordisk built a once-weekly injection into its licensed schedule rather than a daily one. That long half-life means the drug's levels stay relatively stable between doses, and missing a single day does not unwind the week's work in the way a forgotten daily tablet might.

What does matter is consistency. Picking a day (a Monday, a Sunday morning, whenever fits your week) and sticking to it keeps the gap between doses close to seven days each time. It also makes the routine easier to maintain over the months that characterise a full treatment course. There is no requirement to inject at a particular time of day or to fast beforehand; Wegovy's absorption is not meaningfully affected by food in the way that the oral semaglutide tablet is. If you are curious about the rules around timing and frequency, our guide to how often you can inject semaglutide covers what the licensed schedule allows and why the interval is not something you can safely shorten. You can read more about how often you have to inject Wegovy, including why the once-weekly schedule is fixed rather than flexible, on our dedicated guide.

The pen itself (a pre-filled, single-use device) is designed so that the injection process takes only a few seconds once you have set it up. It arrives through the post in a plain, unbranded box with a DPD tracking number, stored safely for the journey so that it reaches your fridge in good condition. If you are new to the pens, our guide to Wegovy pen colors explains how each colour corresponds to a different dose strength, which can help you feel confident you are using the right pen at each stage. That first injection is the only moment most people feel nervous; the mechanics are genuinely straightforward.

The dose escalation schedule and what it means for your routine

Knowing how often to inject Wegovy is only half the picture. The other half is understanding that the dose changes over time, and those changes follow a specific staircase pattern rather than happening at the prescriber's whim.

Treatment opens at 0.25 mg for the first four weeks. This starting dose is a settling-in step, its job is to help your body adjust to semaglutide's effects on gastric emptying and appetite, reducing the likelihood of significant nausea early on. After four weeks the dose moves to 0.5 mg, then 1.0 mg, 1.7 mg and finally 2.4 mg, each step separated by roughly a month. The MHRA has also approved a 7.2 mg dose for adults with a BMI of 30 or above, with a dedicated single-dose pen approved in April 2026 for those who continue treatment beyond the standard 2.4 mg level, your prescriber would assess whether this is appropriate for you.

Throughout all of this, the injection frequency stays the same: once a week. The day does not change when the dose changes. This is a detail worth noting because some people expect to inject more often as the dose increases, they do not. Our guide to how often you take a Wegovy injection explains the reasoning behind this schedule in full, including why the cumulative weekly exposure matters more than increasing how often you inject. The NHS's patient information on semaglutide covers the full escalation schedule in plain language.

Injection technique, site rotation and what to do if something goes wrong

The three approved sites for a Wegovy injection are the abdomen (at least a few centimetres from the navel), the outer thigh and the upper arm. Rotating between these sites each week prevents the build-up of lumps or skin thickening that can develop if the same spot is used repeatedly. Many people find a simple rotation pattern, such as abdomen one week, thigh the next, easier to remember than tracking precise coordinates.

Clean the skin before injecting, alcohol swabs are one practical way to do this. The pen's needle is short and fine; the injection is given at a 90-degree angle into a pinched fold of skin. Used pens and needles should go into a proper sharps container rather than household waste, see our sharps disposal guidance for a suitable option.

Occasionally the pen does not work as expected. If the window does not change colour after the injection, if the pen appears damaged, or if something simply does not feel right, the step-by-step advice for a faulty Wegovy pen walks through what to check. Do not re-inject from the same pen without confirming the dose was delivered, contact your prescriber if you are unsure.

Side effects that are linked to the weekly injection cycle

Most side effects with Wegovy follow the injection schedule. Nausea, loose stools, constipation, indigestion and low appetite tend to peak in the day or two after a dose and ease as the week progresses. They are typically most noticeable after the first injection at a new dose level and settle for most people within a week or two of that step.

Injection-site reactions (mild redness, tenderness or a small lump at the injection point) are common and usually short-lived. Rotating sites consistently is the main way to keep these minimal. Fatigue and headache can also occur, again most frequently after dose changes.

The side effects that warrant urgent attention are not dose-timing-related. Severe, persistent stomach pain that radiates through to the back may indicate acute pancreatitis, and the MHRA's updated safety guidance on GLP-1 medicines recommends seeking immediate medical help if this occurs, you can report any suspected side effect via the Yellow Card scheme. Gallbladder symptoms, signs of a serious allergic reaction and any thoughts of self-harm are also grounds for prompt medical contact. Details of the full side-effect profile are covered in the Wegovy treatment overview.

If you are weighing up whether Wegovy fits your situation, or want to understand what a clinical review involves before committing, our free consultation is the place to start. A GPhC-registered prescriber reads every response personally and will confirm whether treatment is suitable for you.