Your First Week on Wegovy: What to Expect Day by Day

Step 1: Injection day and the hours that follow

Your first Wegovy injection goes into the fatty tissue of your abdomen, thigh, or upper arm, rotate the site each week. The pen is pre-filled and pre-set at 0.25mg; you do not adjust anything. After injecting, most people feel nothing unusual for several hours. Semaglutide is absorbed slowly from the subcutaneous tissue, reaching peak concentration roughly 24–72 hours after the injection rather than straight away.

If nausea arrives, it tends to show up somewhere in that window. It is usually mild (a background queasiness rather than acute illness) and most people find it is manageable with small, plain meals. Eating a large or fatty meal shortly after injecting tends to make it worse. The first day on Wegovy is also covered in detail separately if you want a closer look at those early hours.

Some people inject on a Monday morning before work; others pick a Friday so any tiredness or nausea falls over a quieter weekend. There is no medically superior day, pick one that fits your week and stick to it. Missing a full week, say over a holiday, changes the schedule; that is a question for your prescriber, not something to self-manage.

Step 2: Days two to four, where most of the adjustment happens

This is typically when the GI effects are most noticeable, if they appear at all. Nausea, loose stools, constipation, or indigestion can each occur; they rarely all happen together. The NHS semaglutide medicines page lists these as common side effects and notes they are generally mild to moderate.

Fatigue is reported by some people in the first few days too. It passes. Drinking water consistently helps, partly because reduced appetite can lead people to eat and drink less than their body needs. Protein at each small meal (eggs, fish, yoghurt, pulses) tends to support energy better than snacking on refined carbohydrates. These are general dietary principles; your prescriber can advise on what is right for your specific circumstances.

Appetite suppression at this stage varies widely. Some people feel a clear drop in hunger from the second day. Others feel very little change in the first week and wonder whether anything is happening, and if you want a full picture of what those early days typically look like, our guide to the first week on Wegovy covers what is and is not within the normal range at this dose. The medicine's appetite effect compounds over weeks of titration, not days. Our guide to how long Wegovy takes to work puts the timeline in context.

Step 3: Days five to seven, settling into the rhythm

By the end of the week, most people report that any nausea has eased considerably. The body adapts quickly to this dose. If symptoms have been genuinely severe (persistent vomiting, inability to keep fluids down, or severe stomach pain that spreads to your back) those are reasons to contact a clinician rather than wait it out. The MHRA has highlighted acute pancreatitis as an infrequent but serious potential side effect of GLP-1 medicines; severe, persistent abdominal pain is a reason to seek urgent medical attention.

Weight on day seven is unlikely to look different from day one on the scales. That is not a failure; it reflects how this class of medicine works. The STEP 1 trial, published in the New England Journal of Medicine, showed an average 14.9% body-weight reduction over 68 weeks, sustained, gradual loss, not a week-one drop. You can read more about the longer arc on our page covering what to expect in the first month on Wegovy.

The week ends with something practical: note what you ate, how you felt after the injection, and whether any symptoms were troublesome enough to mention at your next clinical review. That record is genuinely useful. For those curious about how the experience shifts once the dose increases, the second week on Wegovy follows a similar pattern, still at 0.25mg, still about adjustment. The titration schedule is set by your prescriber, not by how quickly you want to move up.

Wegovy is a prescription medicine requiring clinical assessment before it can be dispensed. If you are weighing up costs alongside the clinical side, the Wegovy pricing page gives an honest picture of what private treatment involves. When you are ready to talk to a clinician, our team at nume's consultation hub can walk you through whether semaglutide suits your situation.