Reviewed by GPhC Pharmacist at Priory Pharmacy, York
Wegovy (semaglutide 2.4 mg, injected under the skin) was the first GLP-1 medicine approved in the UK just for weight management. It was approved based on the STEP trial programme. These trials showed weight loss beyond anything previously licensed without surgery.
Demand for Wegovy has been high since it became available in the UK. If you’re considering it, it helps to understand:
- What the medicine is
- What evidence supports it
- What treatment actually involves
How Semaglutide Works and Why It Leads to Weight Loss
Semaglutide is a GLP-1 receptor agonist. In simple terms, it’s a lab-made version of a natural hormone in your body called GLP-1. It’s been altered so it lasts longer about one week in your system. That’s why you only need to inject it once a week.
It works in two places:
- In the brain (hypothalamus): it reduces appetite and helps you feel full
- In the gut: it slows down how fast your stomach empties, so fullness lasts longer after eating
What patients notice:
- Less interest in food
- Fewer food cravings
- Feeling full sooner
Important point: this isn’t about “willpower” or forcing yourself to eat less. The medicine changes your body’s hormone signals around hunger and fullness. Obesity involves disrupted signalling in this system semaglutide helps correct part of that.
The STEP Trial Programme: What Was Found
STEP stands for “Semaglutide Treatment Effect in People with Obesity.” It’s a set of randomised controlled trials testing semaglutide 2.4 mg for weight management.
STEP 1 (the main trial)
- Who took part: adults with a BMI of 30 or above (or 27+ with a related health condition), without type 2 diabetes
- Length: 68 weeks
Results:
| Outcome | Semaglutide | Placebo |
|---|---|---|
| Average weight loss | 14.9% of body weight | 2.4% |
| Lost at least 10% of body weight | 69% of people | — |
| Lost at least 15% of body weight | 50% of people | — |
STEP 4 (what happens if you stop treatment)
This trial looked at people who lost significant weight on semaglutide, then switched to a placebo (dummy treatment).
- They regained about two-thirds of their lost weight within 52 weeks
What this means: semaglutide treats a long-term condition. It isn’t a short course you complete and stop. Keeping the weight off means staying on treatment similar to how blood pressure medicine needs to be continued to keep blood pressure controlled.
Starting Wegovy: How the Dose Increases
You start on a low dose and build up slowly. This is called titration.
The schedule:
- Start dose: 0.25 mg, once a week
- The dose increases by 0.25 mg every 4 weeks
- Target dose: 2.4 mg per week
- It takes about 16–20 weeks to reach the full target dose
Why go slowly? A gradual increase lowers the risk of stomach side effects. These side effects mostly happen while the dose is going up. They usually improve once you’re settled on a steady dose.
A Higher Dose Option (from January 2026)
- A new 7.2 mg dose was approved for patients with a starting BMI of 30 or above
- In the Phase 3b STEP UP trial (72 weeks):
- 7.2 mg dose: average weight loss of 20.7% of body weight
- Standard 2.4 mg dose: average weight loss of 17.5% of body weight
Heart Health Benefits: A Growing Area of Evidence
The SELECT trial (2023) looked at adults who:
- Already had heart disease
- Were overweight or had obesity (BMI 27 or above)
- Did not have diabetes
Key finding: semaglutide 2.4 mg reduced major heart problems heart-related death, non-fatal heart attack, and non-fatal stroke by 20% compared to placebo. The trial followed patients for an average of 39.8 months.
Importantly, this benefit didn’t depend on how much weight someone lost. This strengthens the case for Wegovy in patients who have heart risks and also meet the criteria for weight management treatment.
Wegovy at Priory Pharmacy in York
We offer Wegovy as part of a structured, clinically supervised programme. It includes:
- An initial clinical assessment
- Prescribing, where appropriate
- Monitoring as your dose increases
- Ongoing clinical reviews
- Support managing side effects
- Lifestyle support
Weight management medicine works best as part of a full, supported programme not on its own.
This article gives general information. It is not personal medical advice. To discuss Wegovy or other weight management options at Priory Pharmacy in York, please book a consultation.
Frequently Asked Questions
Wegovy (semaglutide 2.4 mg) works by mimicking the GLP-1 hormone, which helps regulate appetite and food intake. It can help people feel fuller for longer, reduce hunger and support weight loss when combined with a healthy diet and regular physical activity.
Wegovy may be suitable for adults with obesity or those who are overweight and have weight-related health conditions. Eligibility depends on factors such as body mass index (BMI), medical history and whether treatment is clinically appropriate following an assessment by a healthcare professional.
Results vary from person to person. Some people notice changes in appetite and weight within the first few weeks, while more significant weight loss usually occurs over several months when Wegovy is combined with long-term lifestyle changes and regular follow-up.