Wegovy Information: What You Actually Need to Know Before Starting

Step 1, Understanding semaglutide and why the dose starts low

Semaglutide, the active ingredient in Wegovy, belongs to a class of medicines called GLP-1 receptor agonists. GLP-1 is a hormone your gut releases after eating; it signals the brain to reduce appetite, slows gastric emptying so you feel full for longer, and has effects on how the body handles blood sugar. Wegovy delivers a pharmacological dose of that signal once a week, sustaining appetite suppression across the whole week rather than just after meals.

The titration schedule is not arbitrary. Treatment begins at 0.25 mg weekly, a dose too low to produce meaningful weight loss on its own, because starting low gives the digestive system time to adjust and substantially cuts the chance of nausea in the first weeks. Your prescriber then steps the dose up (through 0.5 mg, 1.0 mg and 1.7 mg) roughly every four weeks, with the standard maintenance dose of 2.4 mg reached after around four months. In April 2026, the MHRA approved a dedicated 7.2 mg single-dose pen for adults with a BMI of 30 or above, extending the maximum licensed dose for those who need it. Detailed information on how this medicine is dosed and stored sits in the semaglutide prescribing information resources available through regulated services.

One practical point most people find useful: the pen lives in the fridge between uses, so linking the weekly injection to something already in your fridge routine (checking it is there when you put the shopping away, for instance) helps with consistency. The NHS medicines page for semaglutide sets out storage requirements in full.

Step 2 (Who Wegovy is licensed for and what NICE says

The UK licence for Wegovy covers adults with a BMI of 30 or above, or a BMI of 27 to 29.9 where at least one weight-related condition is present) things like high blood pressure, type 2 diabetes, obstructive sleep apnoea or high cholesterol. Lower BMI thresholds apply for some ethnic backgrounds under UK clinical guidance, typically 2.5 kg/m² below the standard figure.

NICE reviewed Wegovy in TA875 and recommended it, but with conditions that matter for anyone exploring the NHS route: it is recommended only within a specialist weight management service, used for a maximum of two years, and continued beyond six months only if the person has lost at least 5% of their starting weight on the maintenance dose. Those conditions reflect how NICE assessed cost-effectiveness, not the medicine's safety profile. The full NICE recommendation is worth reading directly at NICE TA875.

On the NHS, access to Wegovy typically requires a referral to a specialist service, and waiting lists vary considerably by area. For people who do not meet current NHS criteria or prefer not to wait, private treatment through a GPhC-registered pharmacy is the regulated alternative. Information about the wider range of licensed weight-loss options available in the UK is on the weight loss treatments overview. Separately, for anyone comparing Wegovy against tirzepatide, the Wegovy product information page sets out specifics side by side with the evidence.

Step 3, What the trial evidence actually shows

The pivotal trial for Wegovy at the 2.4 mg dose was STEP 1: 1,961 adults with obesity or overweight plus a weight-related condition, 68 weeks, with lifestyle support in both arms. Participants using semaglutide lost an average of around 15% of their body weight, against roughly 2.4% in the placebo group. That is a meaningful difference, though it is worth being clear that "average" covers a wide spread, some people lose considerably more, others less. The STEP 1 paper in the New England Journal of Medicine sets out the full dataset.

At the newer 7.2 mg dose, 72-week trial data reported average weight loss of around 20.7%, narrowing the gap with tirzepatide 15 mg seen in the SURMOUNT-5 head-to-head. These are still quoted as averages from controlled trial conditions alongside lifestyle intervention, results in real-world practice vary, and no ethical service guarantees a specific outcome for any individual.

People often search for information on Wegovy weight loss expecting a single number. The honest answer is a range shaped by dose, adherence, baseline weight and lifestyle factors. That is why clinical review before and during treatment matters: a prescriber can assess how the medicine is working for you specifically, not just statistically. Our Wegovy patient information page covers what to track and discuss with your prescriber as treatment progresses.

Step 4, Side effects, safety monitoring and when to seek help

The most common side effects with Wegovy are gastrointestinal: nausea, vomiting, diarrhoea, constipation, indigestion and burping feature most often. They tend to be most noticeable in the first days after a dose increase and usually ease within one to two weeks as the body adjusts. Fatigue, headache and dizziness are also reported. Some people find that abdominal bloating is a persistent issue; the Wegovy bloat page and bloating relief guidance offer practical approaches, though anything that concerns you should go to your prescriber first.

Rare but serious effects require prompt medical attention: severe, persistent stomach pain that radiates to the back (a potential sign of pancreatitis), symptoms of gallbladder problems, and signs of a serious allergic reaction. The MHRA issued a Drug Safety Update in January 2026 specifically highlighting acute pancreatitis as a known risk with GLP-1 medicines, underscoring that patients and clinicians should act quickly on that symptom pattern. Suspected side effects can be reported at the MHRA's Yellow Card scheme.

Wegovy is not recommended during pregnancy, while breastfeeding, or for people actively trying to conceive. It is not licensed for anyone under 18. These are firm boundaries, not suggestions, if your circumstances change during treatment, tell your prescriber immediately. Our clinical team, led by Mostafa Damghani, reviews every case individually and can advise on how to manage treatment safely around changing health situations.