Wegovy Weight Loss Shots: What Actually Happens When You Start

You've just been told Wegovy might suit you, here's the biological reality of those shots

Picture this: you're sitting with a 0.25mg pen, told by your prescriber to inject once a week for a month before increasing. The dose feels almost symbolic. That's intentional. The starter pen exists to let your digestive system adjust, not to produce dramatic results. Semaglutide works by binding to GLP-1 receptors, the same receptors activated by a hormone your gut releases after a meal. When those receptors are stimulated, your brain receives signals of fullness sooner and for longer, gastric emptying slows, and appetite drops. The effect builds across weeks as the dose climbs.

What changes first is usually hunger. Many people notice they feel satisfied with smaller portions before they notice anything on the scale. That shift in appetite is the mechanism at work, and understanding it helps set expectations: if you want a closer look at how these weekly Wegovy shots work in practice, including what each pen stage involves, that detail is worth reading before you begin. You can read more about what this medicine is and how it fits into weight management on our Wegovy overview page.

The titration schedule (0.25mg, then 0.5mg, then 1.0mg, then 1.7mg, then 2.4mg) is guided by your prescriber and follows the licensed pathway set out in the Summary of Product Characteristics. The MHRA approved a higher 7.2mg maintenance dose in 2026, initially as three weekly 2.4mg pens and subsequently as a dedicated single-dose pen. Whether that option is appropriate for any given patient is a clinical decision. The NHS has published a patient-level overview of semaglutide's effects and what to expect during treatment.

What early weeks of weight loss shots with Wegovy actually feel like

A question our prescribers hear most weeks: "I feel sick, is that normal?" Yes, for most people, it is. Nausea is the most commonly reported side effect, particularly after a dose increase, and it usually eases within a few days to two weeks as your system adapts. Vomiting, loose stools, constipation, reflux and fatigue all appear in the trial data, again mostly at lower severity and typically in the weeks following a step-up in dose.

The practical upshot: starting a new dose on a day when you can rest is sensible. Eating smaller, plainer meals and staying well-hydrated helps most people through the adjustment. Greasy or very sweet foods tend to make GI symptoms worse. None of this is a reason to push through severe symptoms without speaking to your prescriber, that conversation matters, and it's what aftercare is for.

On safety: the MHRA's guidance is clear that pancreatitis is a known but uncommon risk with GLP-1 medicines. Severe, persistent stomach pain that radiates toward the back, with or without vomiting, is a reason to seek urgent medical attention, not to wait it out. Reporting any suspected side effects through the MHRA's Yellow Card scheme contributes to the ongoing monitoring of these medicines. Wegovy holds a Black Triangle (▼) status precisely because that monitoring is still active.

For detail on injection technique and rotating sites, the guide to how Wegovy shots are taken covers that step by step.

Who Wegovy shots are licensed for, and what the evidence says about results

The UK licence covers adults with a BMI of 30 or above, or those with a BMI of 27 to 29.9 alongside at least one weight-related condition such as high blood pressure, type 2 diabetes, dyslipidaemia or obstructive sleep apnoea. Lower BMI thresholds apply for some ethnic backgrounds under UK guidance. A prescriber reviews the complete picture (not just the number on the scales) before deciding whether treatment is appropriate. BMI is a starting point, not a guarantee either way.

On results: the STEP 1 trial, published in the New England Journal of Medicine, followed 1,961 adults over 68 weeks. Participants using semaglutide 2.4mg alongside lifestyle changes lost around 15% of body weight on average, and our Wegovy weight loss page sets out what those figures mean in real terms, including how results compare across doses and timescales. Those results were achieved alongside a reduced-calorie diet and increased physical activity, the injection works with those changes, not instead of them. The trial at the higher 7.2mg dose reported approximately 20.7% average weight loss over 72 weeks, approaching results seen with tirzepatide at its highest strength. A comparison of the two medicines is available on our semaglutide weight-loss page.

If cost is part of your thinking, our Wegovy prices page sets out what private treatment typically involves and what a single transparent price should cover. Worth reading before you compare providers.

NHS access versus private prescribing, and what the clinical process looks like

On the NHS, Wegovy is available through specialist weight management services under NICE guidance (TA875), which requires multidisciplinary support and caps treatment at a maximum of two years. Waiting lists in many areas are long, and criteria are strict. From April 2026, some GP practices can prescribe under a new contract arrangement, though participation varies by practice and region.

Private prescribing through a regulated online pharmacy like nume is the route many people take when they don't meet NHS criteria, can't wait, or want to get started without a referral. The process is straightforward: a free consultation, reviewed the same day by a real clinician (not automated software), followed by identity and weight verification. Medicines are dispatched through the licensed UK supply chain. Our about page explains how the service is structured and what GPhC registration means for you as a patient.

If you'd like to explore whether Wegovy is the right option for you, or to understand what other licensed weight-loss treatments are available, our clinical team is a good place to start. Speak to our prescribers through a free consultation, no referral needed, assessed the same day.