Starting Wegovy (semaglutide 2.4 mg) for weight management involves a carefully structured treatment journey with gradual dose increases, lifestyle modifications, and regular monitoring. This GLP-1 receptor agonist medication works by reducing appetite and promoting satiety, but understanding what to expect—from initial side effects to long-term weight loss patterns—is essential for success. Most patients experience gastrointestinal symptoms during the first weeks, with progressive weight loss occurring over 12–68 weeks when combined with dietary changes and physical activity. This guide explains the practical aspects of Wegovy treatment, including dosing schedules, side effect management, realistic timelines, and when to seek medical advice.

What Is Wegovy and How Does It Work?

Wegovy (semaglutide 2.4 mg) is a prescription medicine licensed in the UK for weight management in adults (aged 18 and over) with obesity or those who are overweight with at least one weight-related health condition, such as type 2 diabetes or hypertension. It belongs to a class of medications called glucagon-like peptide-1 (GLP-1) receptor agonists, which were originally developed to treat diabetes but have proven highly effective for weight loss.

The medication works by mimicking a natural hormone called GLP-1 that your body produces after eating. Wegovy acts on several areas of the brain involved in appetite regulation, helping you feel fuller for longer and reducing hunger signals. It also slows gastric emptying—the rate at which food leaves your stomach—which contributes to prolonged satiety after meals, though this effect may diminish over time. Additionally, semaglutide influences insulin secretion and glucose metabolism, though at the doses used in Wegovy, the primary therapeutic effect is appetite suppression and reduced caloric intake.

Wegovy is administered as a once-weekly subcutaneous injection using a pre-filled pen device. The injection is typically given in the abdomen, thigh, or upper arm. It's important to understand that Wegovy is not a standalone solution; it must be used alongside a reduced-calorie diet and increased physical activity as part of a comprehensive weight management programme.

In England, Wegovy is available through NHS specialist weight management services for eligible patients who meet specific criteria under NICE guidance (TA875), typically for a maximum treatment duration of 2 years. Access may vary in Scotland, Wales and Northern Ireland. It's also available via private prescription. Your healthcare provider will assess your suitability based on your body mass index (BMI), existing health conditions, and previous weight loss attempts. Wegovy should not be used during pregnancy, breastfeeding, or in combination with other GLP-1 receptor agonists.

Starting Wegovy: Your First Few Weeks

When you begin Wegovy, you won't start at the full therapeutic dose immediately. The medication follows a gradual dose escalation schedule designed to minimise side effects and allow your body to adjust. You'll typically start with 0.25 mg once weekly for the first four weeks, then increase to 0.5 mg for another four weeks. This stepwise approach continues monthly through 1 mg, 1.7 mg, and finally reaches the maintenance dose of 2.4 mg by week 17. If you cannot tolerate the 2.4 mg dose, your doctor may decide to maintain you at 1.7 mg.

During your first few weeks, it's normal to notice changes in your appetite quite quickly—many patients report feeling less hungry and more satisfied with smaller portions within days of their first injection. However, you may also experience some gastrointestinal adjustment symptoms such as mild nausea, which is most common during the initial weeks and dose increases. These effects typically diminish as your body adapts to each dose level.

Practical tips for starting Wegovy include:

• Choose a consistent day and time each week for your injection to establish a routine

• If you miss a dose, take it as soon as possible within 5 days (120 hours) of the missed dose; if more than 5 days have passed, skip that dose and take your next injection on the regularly scheduled day

• Rotate injection sites to prevent skin irritation or lipohypertrophy

• Keep the medication refrigerated (2–8°C) until first use; do not freeze

• After first use, pens can be stored at room temperature (below 30°C) for up to 28 days; protect from light

• Eat smaller, more frequent meals if you experience nausea

• Stay well hydrated throughout the day

• Keep a symptom diary to track side effects and discuss with your healthcare team

Your prescriber should provide comprehensive training on injection technique and pen use before you administer your first dose. Most patients find the injections straightforward and relatively painless. It's essential to attend all scheduled follow-up appointments during the titration phase so your healthcare provider can monitor your response, adjust the escalation schedule if needed, and provide ongoing support.

Common Side Effects and How to Manage Them

The most frequently reported side effects of Wegovy are gastrointestinal in nature, affecting the majority of users to some degree. These include nausea, diarrhoea, vomiting, constipation, abdominal pain, and indigestion. These symptoms are generally mild to moderate and tend to improve over time as your body adjusts to the medication. They're most pronounced during the first few weeks and following dose increases.

Managing nausea and digestive symptoms:

• Eat smaller portions more frequently rather than large meals

• Avoid high-fat, greasy, or heavily spiced foods that may worsen symptoms

• Choose bland, easily digestible foods when nausea is present

• Eat slowly and chew thoroughly

• Avoid lying down immediately after eating

• Consider ginger tea as a potential option for nausea relief

• Stay upright for at least 30 minutes after meals

• Maintain adequate hydration to prevent dehydration, which can lead to acute kidney injury, especially if you have pre-existing kidney problems

For constipation, increase your fibre intake gradually through fruits, vegetables, and whole grains, and ensure adequate fluid consumption (at least 6–8 glasses of water daily). Regular physical activity also promotes healthy bowel function. If constipation persists, speak to your pharmacist about suitable over-the-counter remedies.

Other side effects can include fatigue, dizziness, and headaches, particularly in the early weeks. These usually resolve without intervention. Some patients report changes in taste or reduced enjoyment of food, which while contributing to weight loss, can affect quality of life. Injection site reactions—redness, itching, or mild swelling—occur occasionally but are typically minor and resolve quickly.

Rare but serious side effects include pancreatitis (severe, persistent abdominal pain), gallbladder problems, and changes in vision (particularly in people with diabetes). Animal studies have shown a risk of thyroid tumours, though there is no confirmed link in humans. Your healthcare provider will discuss your individual risk factors before prescribing Wegovy. If side effects become intolerable, your doctor may slow the dose escalation or, in some cases, discontinue treatment.

If you experience any side effects, you can report them via the MHRA Yellow Card Scheme (yellowcard.mhra.gov.uk).

Weight Loss Timeline: What Results to Expect on Wegovy

Weight loss on Wegovy is gradual and progressive, not immediate. Clinical trials have demonstrated that most weight loss occurs over the first 60–68 weeks of treatment, with the rate of loss typically greatest in the first few months before plateauing. Understanding this timeline helps set realistic expectations and prevents disappointment.

Early phase (Weeks 1–12): During the dose escalation period, you may notice modest weight loss as your appetite decreases and you naturally consume fewer calories. Some patients lose 2–5% of their starting body weight during this phase, though individual responses vary considerably. The focus during these weeks should be on adjusting to the medication and establishing healthy eating patterns rather than dramatic weight loss.

Active loss phase (Weeks 12–68): Once you reach the maintenance dose of 2.4 mg, weight loss typically accelerates. Clinical trial data (STEP 1) shows that by 68 weeks (approximately 16 months), participants lost an average of 15% of their initial body weight when combining Wegovy with lifestyle interventions. However, this is an average—some people lose more, others less. Factors influencing your individual response include adherence to dietary changes, physical activity levels, metabolic factors, and starting weight.

Sustained phase (Beyond 68 weeks): Weight loss generally continues but at a slower rate during the second year. The STEP trials demonstrated that patients who continued Wegovy maintained their weight loss, whilst those who discontinued the medication regained a significant portion of the lost weight. This highlights that Wegovy is intended as a long-term treatment rather than a short-term intervention.

In the NHS, treatment is typically provided for up to 2 years through specialist weight management services, in line with NICE guidance (TA875). Your healthcare team will regularly review your progress and the ongoing benefits of treatment. Remember that weight loss is not linear—you may experience weeks with no change or even slight increases, which is entirely normal. Focus on non-scale victories such as improved energy, better-fitting clothes, and health marker improvements like blood pressure or HbA1c levels.

Long-Term Use: Maintaining Your Progress

Wegovy is designed for chronic weight management, meaning it's intended to be used long-term rather than as a temporary measure. Clinical evidence demonstrates that discontinuing the medication typically results in weight regain, as the appetite-suppressing effects cease and hunger signals return to pre-treatment levels. This doesn't represent treatment failure—it reflects the biological nature of obesity as a chronic condition requiring ongoing management.

In the NHS, Wegovy is typically prescribed for up to 2 years through specialist weight management services, in accordance with NICE guidance (TA875). Private prescriptions may follow different timeframes based on clinical judgement and patient needs.

For sustained success on Wegovy, it's essential to view the medication as one component of a comprehensive lifestyle approach. The medication creates a physiological advantage by reducing hunger and cravings, but lasting results depend on establishing sustainable habits around nutrition and physical activity. Work with your healthcare team to develop an individualised plan that includes balanced, nutrient-dense meals, regular physical activity you enjoy, adequate sleep, and stress management strategies.

Monitoring and follow-up remain important throughout treatment. Your healthcare team will schedule regular reviews to assess:

• Weight loss progress and maintenance

• Side effect management and tolerability

• Improvements in obesity-related health conditions (blood pressure, cholesterol, blood glucose)

• Adherence to lifestyle modifications

• Psychological wellbeing and relationship with food

Some patients reach a point where they maintain a stable, healthier weight and may wish to discuss discontinuation or dose reduction with their clinician. There is currently limited evidence on optimal strategies for stopping Wegovy, and decisions should be individualised through shared decision-making. Your healthcare provider will consider factors such as weight stability, health improvements, and your confidence in maintaining lifestyle changes without medication support.

If you're planning a pregnancy, you should stop Wegovy at least 2 months before attempting to conceive. Effective contraception is recommended while taking Wegovy. The medication should not be used during pregnancy or while breastfeeding.

It's worth noting that Wegovy is a relatively new treatment for obesity, and long-term safety data beyond two years is still accumulating. Your healthcare team will continue to monitor emerging evidence and adjust recommendations accordingly.

When to Contact Your GP While Taking Wegovy

Whilst most people tolerate Wegovy well, certain symptoms require prompt medical attention. Understanding when to seek help ensures your safety and allows timely management of potential complications.

Seek emergency care (call 999 or go to A&E) if you experience:

• Symptoms of severe allergic reaction: difficulty breathing, severe rash, swelling of face or throat

Contact your GP or healthcare provider urgently if you experience:

• Severe, persistent abdominal pain that doesn't resolve, particularly if radiating to your back—this could indicate pancreatitis, a rare but serious side effect requiring immediate assessment

• Persistent vomiting that prevents you from keeping down fluids, as this can lead to dehydration and potential kidney problems

• Signs of gallbladder problems: sudden pain in the upper right abdomen, yellowing of skin or eyes (jaundice), fever, or clay-coloured stools

• Changes in vision or difficulty seeing, especially if you have diabetes

• Signs of dehydration or kidney problems: extreme thirst, dark urine, dizziness, confusion, reduced urination, or swelling

• Rapid heartbeat or palpitations that are new or concerning

• Severe or worsening depression, or thoughts of self-harm—there have been reports of mental health changes in some patients taking weight loss medications

You should also contact your healthcare provider (non-urgently) if:

• Side effects are significantly affecting your quality of life or preventing you from eating adequately

• You're losing weight too rapidly (more than 1–2 kg per week consistently)

• You're not losing weight despite adherence to the treatment plan

• You're planning pregnancy or discover you're pregnant—Wegovy should be discontinued at least 2 months before attempting to conceive

• You develop any new symptoms or health concerns

• You're struggling with the injection technique or have questions about medication storage

If you experience symptoms of low blood sugar (hypoglycaemia)—shakiness, sweating, confusion, rapid heartbeat—this is more likely if you're also taking insulin or sulfonylurea medications for diabetes. Check your blood glucose if possible, treat according to your sick day rules, and contact your diabetes team to discuss medication adjustments. Always attend your scheduled follow-up appointments, as regular monitoring is an essential part of safe, effective treatment with Wegovy.

Frequently Asked Questions