A Wegovy diary: what the first weeks on semaglutide actually look like

Week one: the pen is smaller than you imagined, and so is the dose

Picture the scene: your Wegovy pen arrives in plain packaging, refrigerated with a cold pack, on a Tuesday morning. You've read the leaflet twice. The 0.25mg starting dose feels almost anticlimactic — because it is designed to be. That first dose is not where the clinical work happens; it is the period your body uses to adapt to semaglutide before the dose steps up. Many people notice very little in week one beyond mild nausea a few hours after the injection, if anything at all.

Injection day matters more than people expect. The full Wegovy treatment guide explains the administration routine in detail, but the short version is this: rotate your sites (abdomen, thigh or upper arm), keep the pen refrigerated between uses, and inject on the same day each week. Setting a calendar reminder takes thirty seconds and removes the single biggest avoidable error.

Your appetite in week one may feel unchanged. That is fine. The dose is intentionally low. What a diary entry in week one is actually useful for is logging your baseline: how hungry you feel before meals, how quickly you fill up, how much you think about food between meals. That baseline becomes the comparison point in weeks six, ten and beyond, when the changes are far more obvious.

Weeks two to four: when the appetite shift starts to land

For most people, the hunger picture starts to shift somewhere in weeks two to four. Food just becomes less insistent. You might notice you stop eating halfway through a meal and feel genuinely satisfied rather than deprived. This is semaglutide working as a GLP-1 receptor agonist: it slows gastric emptying and signals fullness to the brain. The semaglutide overview page has more on the mechanism if you want the clinical detail.

Nausea is the side effect diary-writers mention most. It tends to peak in the first day or two after each dose and then ease. Eating smaller portions, avoiding fatty or very rich food around injection day, and staying well hydrated all help. Most people find it manageable; a small number find it significant enough to discuss with their prescriber. That conversation is always worth having rather than quietly stopping treatment.

Fatigue shows up in some diaries too, usually in the first couple of weeks at a new dose. It is not universal, and it generally settles. What does not settle on its own is severe or persistent stomach pain, especially pain that radiates towards the back. The MHRA highlighted acute pancreatitis as an infrequent but serious risk with GLP-1 medicines in its January 2026 Drug Safety Update, if that symptom pattern develops, seek urgent medical help rather than waiting for it to pass. You can report unexpected side effects at the MHRA's Yellow Card service.

The middle weeks: titration and what the dose increases feel like

Wegovy follows a stepped titration from 0.25mg up through 0.5mg, 1.0mg, 1.7mg and eventually to 2.4mg maintenance, with roughly four weeks at each level. Some people stay at a lower dose for longer if they are managing side effects; the prescriber makes that call. Each dose increase can bring a brief return of nausea, and if you want to understand what to expect when you reach that second step, our guide to the 0.5mg Wegovy dose covers how that stage typically feels and what to watch for.

This is where a diary becomes genuinely useful rather than just interesting. Logging how you felt in the first 48 hours at 0.5mg gives you real information to bring to your next review. Did you feel fine? Rough for a day? Nauseous for a week? That history helps a prescriber decide whether you are ready for the next step or would benefit from a slower approach. If you are thinking about starting treatment, the guide to accessing Wegovy through a regulated UK pharmacy explains what the clinical review process involves.

Weight change across the titration phase varies a great deal. The STEP 1 trial, published in the New England Journal of Medicine, reported around 15% average weight reduction over 68 weeks at 2.4mg. That is an average across a large group, not a personal forecast. Some people lose weight steadily throughout titration; others find their body is slower to respond until they reach a higher dose. Neither pattern signals that something is wrong.

Building habits alongside the medicine

One thing that comes through clearly in clinical guidance is that semaglutide works alongside diet and activity changes, not instead of them. When your appetite is quieter, it is easier to make consistent food choices and to eat adequate protein, which matters for preserving muscle during weight loss. The NHS England guidance on weight management injections is explicit that lifestyle support runs alongside the medicine throughout treatment.

If you are weighing up whether Wegovy is right for your situation, comparing it with other licensed options can help, the weight-loss treatment overview covers the landscape clearly. And if you are already on a different dose or want to understand the clinical criteria in more detail, the 2.0mg Wegovy dosing page and our frequently asked questions are good places to look.

Keeping a diary is ultimately a tool for staying engaged with your own progress. It does not need to be elaborate. A note of your injection day, how you felt, what you ate and how hungry you were takes about three minutes. Over three months, that log tells a story a prescriber can actually use. If you are at the very beginning of that journey, our guide to the first week of Wegovy treatment is a practical starting point before you explore whether semaglutide treatment is suitable for you. When you are ready, check your eligibility with our clinical team.