Taking your second dose of Wegovy: what happens, and what to expect

What does the second dose of Wegovy actually involve?

The mechanics of the second injection are identical to the first. You'll use a new pre-filled Wegovy pen at the 0.25 mg strength, injecting into the fatty tissue of your abdomen, thigh or upper arm. Rotating the exact spot within that area each week reduces the chance of skin irritation at the site. The full guide to Wegovy covers the pen technique in more detail if you want a refresher before you begin.

Timing matters in a straightforward way: pick the same day of the week you used for your first dose and stick to it. Some people anchor it to something predictable, a Sunday morning routine, for instance, before the kettle has boiled. That consistency makes it easier to build the habit and harder to accidentally skip a week. If your chosen day shifts by a day occasionally, that is usually fine, but your Patient Information Leaflet and prescriber are the right people to guide you on the exact flexibility window. Our page on what to do if a Wegovy dose is late covers the missed-dose rules in plain terms.

Storage between doses is straightforward: keep unused pens refrigerated at 2–8°C. The used pen from week one should go into a sharps container; never recap or reuse it.

Will side effects be different the second time?

For many people, the second dose is where the treatment starts to feel more real. The first injection can pass with little obvious effect; the second is sometimes when mild nausea, loose stools or a reduced appetite first appear. This is not a sign that something has gone wrong. Wegovy works as a GLP-1 receptor agonist, slowing gastric emptying and influencing appetite signals in the brain, and the gastrointestinal system sometimes needs a few weeks to adjust to that shift.

The NHS semaglutide medicines page lists the common side effects (nausea, diarrhoea, constipation, indigestion, headache and fatigue appear most often) and notes that they are typically mild to moderate and often ease within the first couple of weeks. Most people find that eating smaller portions, avoiding very fatty or rich meals and staying well hydrated takes the edge off. Our dedicated page on side effects around the second Wegovy dose goes into this in more depth.

Seek urgent medical attention if you develop severe, persistent abdominal pain that radiates to your back, with or without vomiting. The MHRA has highlighted acute pancreatitis as a known, though infrequent, serious side effect of GLP-1 medicines, you can report any suspected side effect directly at yellowcard.mhra.gov.uk.

Does the dose change after the second injection?

Not immediately, and usually not for a few weeks yet. The standard Wegovy schedule begins at 0.25 mg for the first four weeks, so your second injection, and your third and fourth, are all at this starting level. The 0.25 mg dose exists to help your body settle into treatment rather than to produce significant weight loss; most of the clinical work happens at the higher maintenance doses reached later in the titration schedule.

After four weeks at 0.25 mg, the next step is typically 0.5 mg, then 1.0 mg, 1.7 mg and eventually the standard 2.4 mg maintenance dose, though how quickly you move through those steps depends entirely on how you are tolerating each level. Your prescriber reviews this before any change is made. The Wegovy doses guide explains the full schedule and what each phase is designed to achieve. It is also worth knowing that how you take each Wegovy dose stays consistent in technique even as the strength increases.

If you are curious about how private treatment costs work as you progress, the Wegovy price comparison guide for the UK sets out what to look for and what a transparent, all-in price should include.

When should you talk to your prescriber rather than waiting?

Side effects that are severe, that do not ease after the first week or two, or that are affecting your ability to eat or drink properly are worth raising promptly. The same goes for any uncertainty about whether you have taken your dose correctly, whether you have accidentally injected into the wrong area, or whether you have stored your pens properly. These are not trivial questions, they affect how well treatment works and whether it is safe to continue at the current level.

At nume, a real clinician reviews every consultation and every repeat order. There is no algorithm deciding whether to progress your dose. If something about the second injection feels off, or you are not sure about the 0.25 mg starting phase, speaking to our clinical team directly is the right move. You can also read more about the team behind the service on the clinical team page. For questions that are less urgent, our FAQs cover a lot of the ground our prescribers hear most often.