How Wegovy Works and What to Expect in the First Four Weeks

Wegovy contains semaglutide, a medication that targets the GLP-1 system. Unlike Mounjaro, which works on two hormone pathways, Wegovy works on GLP-1 alone. This makes it a simpler, single-target approach to weight loss. Many people find Wegovy very effective, with clinical trials showing weight loss of 15-22% of body weight over 68 weeks.

What Is Semaglutide?

Semaglutide is a GLP-1 receptor agonist, meaning it binds to GLP-1 receptors in your body and mimics the natural hormone. It signals your pancreas to release insulin, tells your brain you are full, and slows stomach emptying. It has been used safely for type 2 diabetes for years (as Ozempic) before being approved for weight loss at higher doses (as Wegovy).

Week 1: Starting Your Treatment

You will start Wegovy at the lowest dose (0.25 mg), injected under the skin once a week. Like Mounjaro, most people notice effects within days. Mild nausea is common on injection day but usually settles quickly. By the end of week 1, you may notice that your appetite is less insistent. Previously tempting foods may not appeal as much.

Week 2: Appetite Suppression Begins

By week 2, appetite suppression becomes obvious. You will likely find you eat less without conscious effort. Portion sizes naturally shrink. You might feel full on half of what you previously ate. Nausea is usually mild and most noticeable when eating fatty or sugary foods. The key is to adapt your diet to lighter, simpler meals while your body adjusts.

Week 3: Food Interest Decreases

By week 3, food interest often drops significantly. You might skip meals because you forget to eat. Cravings typically reduce. The psychological drive to eat reduces considerably. This is the benefit that makes sustained weight loss possible: eating less no longer feels like deprivation because you genuinely want less.

Week 4: First Dose Increase

At 4 weeks, you will escalate to 0.5 mg. Most people have lost 1-3 kg by this point. Weight loss with Wegovy is often a bit slower than Mounjaro in the early stages because the medication works on one hormone system rather than two. However, it continues steadily and many people eventually lose the same amount.

Managing Early Side Effects

Wegovy side effects are similar to Mounjaro. Nausea is the most common, followed by constipation or loose stools. Here is how to manage them:

• Eat smaller, more frequent meals rather than three large ones.
• Choose bland, easily digestible foods: chicken, rice, toast, vegetables.
• Drink plenty of water throughout the day.
• Avoid alcohol and caffeine, which can worsen nausea.
• Take your injection in the evening so any nausea happens while you sleep.
• Try motion sickness bands if nausea is significant.

Side effects are usually mild and temporary, improving after 1-2 weeks as your body adjusts to each new dose.

Expected Weight Loss Timeline

In the first month, expect to lose 1-3 kg on Wegovy. This slower initial loss compared to Mounjaro reflects its single-target mechanism. However, as you escalate the dose and reach 1.0 mg (the standard maintenance dose), weight loss accelerates. By 12 weeks, many people have lost 5-10% of their body weight. By 6 months, weight loss of 15% is typical.

Wegovy vs Ozempic: What is the Difference?

Both Wegovy and Ozempic contain the same active ingredient: semaglutide. The difference is the dose. Ozempic is prescribed for type 2 diabetes at doses up to 1.0 mg. Wegovy is prescribed for weight loss and uses the same doses as Ozempic, despite sometimes being referred to as a "weight loss drug". The medication is identical; only the indication and marketing differ.

Practical Tips for Success

To maximise your results on Wegovy, keep these points in mind: take your injection at the same time each week (many people choose Sunday evening), eat protein at each meal, drink water constantly, do light exercise regularly, and track how you feel (not just the scale). Your prescribing pharmacist will review your progress at 4 weeks.

What Happens Next

You will continue escalating your dose every 4 weeks (0.25 mg → 0.5 mg → 0.75 mg → 1.0 mg) until you reach the standard maintenance dose. Most people reach 1.0 mg by week 16 (4 injections). At this dose, weight loss typically accelerates significantly. Many people continue losing weight steadily for 6-12 months before weight loss plateaus.