The Wegovy pill's OASIS 4 trial showed average weight loss of up to 16.6% at 64 weeks, driven by the same appetite-suppressing, calorie-deficit mechanism used across the GLP-1 medicine class. Research on the Wegovy injection, which shares the same active ingredient, has shown that roughly 20–25% of weight lost is typically lean mass, with the remainder from fat — a ratio broadly consistent with what's expected during successful weight loss by any method. There's no reason to expect the tablet form to behave differently from the injection in this respect, since both deliver the same semaglutide into your system, just via a different route. The two most evidence-backed ways to protect muscle during treatment are adequate protein intake (around 1.2 to 1.6g per kilogram of body weight daily) and regular resistance training, ideally at least twice a week.
The Wegovy pill and the Wegovy injection both deliver semaglutide, just through different routes — oral absorption via the stomach lining for the tablet, versus subcutaneous injection. This matters for muscle preservation because the body-composition research available on semaglutide, including dedicated studies on the injectable form, is directly relevant to what you can expect from the tablet too — see our Wegovy and muscle preservation guide for that evidence in detail. The weight loss itself comes from the same underlying mechanism: appetite suppression leading to a calorie deficit, which is what actually drives both fat loss and any accompanying muscle loss, regardless of whether the semaglutide reaches your system via a tablet or an injection. For what the tablet's own trial showed overall, see our Wegovy pill results guide.
Worth knowing
Because the Wegovy pill is newer to the UK market than the injection, dedicated body-composition studies using DXA (dual-energy X-ray absorptiometry) scans specifically on the tablet form are less extensive than for the injection. However, since both deliver the same active ingredient into the bloodstream, there's a reasonable clinical basis to expect a broadly similar fat-to-muscle loss ratio for both formats.
| Treatment | Body-composition evidence | What it means for you |
|---|---|---|
| Wegovy pill (oral semaglutide) | Dedicated DXA studies on the tablet are less extensive; same active ingredient as the injection | Expect a broadly similar pattern to the injection, and use the same protective strategies |
| Wegovy injection | Research on semaglutide suggests roughly 20–25% of weight lost is typically lean mass | The main reference point for the tablet |
| Mounjaro | A SURMOUNT-1 DXA substudy found around 25% of weight lost was lean mass and 75% fat | A similar ratio to semaglutide |
| Foundayo | No published body-composition data yet, as it only recently launched | Reasoned from the shared GLP-1 mechanism; the same strategies apply |
When your body is in a significant calorie deficit — which is exactly what the Wegovy pill's appetite-suppressing effect creates once you reach an effective dose — it draws on stored energy from multiple sources, not exclusively fat. Muscle tissue is metabolically active and requires energy to maintain, so during periods of reduced calorie intake, particularly if protein intake and physical activity aren't actively supporting muscle retention, some lean mass loss is a normal and expected part of the process. This isn't specific to the Wegovy pill, or even to GLP-1 medicines generally — it happens with any method that produces significant, sustained weight loss.
Prioritise Protein Intake
Protein provides the building blocks your muscles need to repair and maintain themselves, and requirements increase — not decrease — during a calorie deficit. Clinical guidance for GLP-1 treatment generally recommends 1.2 to 1.6g of protein per kilogram of body weight daily, notably higher than the standard 0.8g/kg general recommendation. Since the Wegovy pill's appetite suppression often means eating less overall, deliberately prioritising a protein source at each meal becomes more important, not less. See our dedicated nutrition guide for a full breakdown of protein targets and food sources.
| Body weight | Daily protein at 1.2g/kg | Daily protein at 1.6g/kg |
|---|---|---|
| 70kg (11 st) | 84g | 112g |
| 90kg (14 st 2 lb) | 108g | 144g |
| 110kg (17 st 5 lb) | 132g | 176g |
Illustration of the 1.2–1.6g/kg guidance only. Your prescriber can help tailor a target to your health and circumstances.
Resistance Training, Not Just Cardio
- Aim for at least two resistance training sessions a week, focusing on compound exercises that work multiple muscle groups (squats, presses, rows) rather than isolated single-muscle exercises
- If you're new to strength training, starting with bodyweight exercises is a reasonable and effective entry point — you don't need a gym or equipment to begin
- Resistance training sends your body a genuine signal to retain and build muscle, even in a calorie deficit, which cardio alone doesn't provide to the same degree
Avoid an Overly Aggressive Calorie Deficit
A calorie deficit of roughly 10–25% is generally considered sustainable without disproportionately compromising lean mass. Since the Wegovy pill can suppress appetite quite significantly once you reach an effective dose, some people end up in a much larger deficit than intended simply because they're not hungry — eating deliberately even when appetite is low, rather than skipping meals, helps avoid an unnecessarily steep deficit. Our calorie deficit calculator can help you see what a sensible range looks like for you.
Don't Under-eat on Purpose
It might seem logical that eating even less would speed up weight loss, but severely restricting calories on top of the medicine's own appetite suppression tends to accelerate muscle loss disproportionately, without meaningfully accelerating fat loss. If you're struggling to eat enough due to reduced appetite, a protein shake or nutritionally complete drink between meals can help you reach your protein target without needing to eat a large volume of food — just remember these don't count toward your morning dosing water allowance and should be taken well after your 30-minute post-dose window (see our guide to the sip & go routine).
| Strategy | Practical action |
|---|---|
| Protein | Include a protein source at every meal; consider a protein shake if appetite is very limited |
| Resistance training | At least 2 sessions weekly, focusing on major muscle groups |
| Calorie deficit | Avoid restricting further than your appetite naturally suggests |
| Titration pace | Progress through your schedule steadily rather than rushing, giving your body time to adjust |
| Hydration | Stay well hydrated, since this supports both muscle function and recovery |
Important
If you're new to resistance training or have any existing health conditions, particularly joint or cardiovascular issues, it's worth speaking to your GP or a qualified trainer before starting a new exercise programme. Building up gradually is safer and more sustainable than starting too intensively.
Muscle is metabolically active tissue, meaning it burns calories even at rest, and maintaining more of it supports your metabolic rate as you lose weight — which also helps when you move on to maintaining your results, as covered in our Wegovy pill long-term use guide. Muscle also plays a central role in mobility, balance, and long-term functional independence, particularly as people age; our Wegovy pill guide for women over 40 covers this life stage in more detail. For older adults especially, unintentional muscle loss during rapid weight loss carries genuine long-term risks around frailty and reduced physical function, which is exactly why the preservation strategies in this guide matter as much as the weight loss itself.
Tracking Progress Beyond the ScaleSince the scale can't distinguish between fat loss and muscle loss, relying on weight alone can be misleading. If protecting muscle matters to you, consider tracking additional measures alongside weight: how your clothes fit, strength progress in the gym (are you maintaining or improving your lifts, even as weight drops?), and if accessible, periodic body composition measurements. Strength that holds steady or improves during weight loss is a genuinely reassuring sign that muscle is being protected, regardless of what the scale alone shows. Body composition also plays a part in how your skin adapts as you lose weight — see our guide to loose skin after weight loss.
Timing Protein and Exercise Around Your TitrationSide effects tend to be most noticeable in the days following a dose increase — our Wegovy pill side effects guide explains what to expect — which can make both eating enough protein and exercising feel harder during that window. Rather than abandoning your routine entirely during a difficult few days, many people find it helpful to focus on smaller, more frequent protein-rich meals, and to keep exercise lighter (a walk rather than a heavy session) until symptoms ease, then return to your normal resistance training routine as you start to feel better. Consistency over the following weeks matters more than any single session. For the full timeline of dose steps, see the Wegovy tablets dose schedule.
Protect Your Muscle, Not Just Your Weight
Our GPhC-registered pharmacy team can talk through practical nutrition and lifestyle strategies to help you protect muscle mass while taking the Wegovy pill.
Start Your Free Online Consultation → Happy Pharmacy is a GPhC-registered pharmacy (No. 9013192) — Superintendent Pharmacist: Palvinder Deol — Rated 4.8★ Excellent on Trustpilot- Wegovy® 25mg tablets, UK Summary of Product Characteristics, medicines.org.uk (emc).
- Wharton S, Lingvay I, Bogdanski P, et al. Oral semaglutide at a dose of 25 mg in adults with overweight or obesity (OASIS 4). N Engl J Med. 2025;393(11):1077–1087.
- GLP-1 and Muscle Loss: Semaglutide, Tirzepatide and Lean Mass. Clinical review, 2026.
- Effects of GLP-1 Receptor Agonists on Body Composition: A Systematic Review. Diabetes, Obesity and Metabolism.