Three of the most-prescribed GLP-1 medications. All approved for weight management (or used off-label where regional regulation lags). All produce significant fat loss. They differ in active ingredient, efficacy, side-effect profile, dosing, and price. Here is the 2026 decision guide.
At a glance
| Drug | Active | Dosing | Avg fat loss | SA price/mo |
|---|---|---|---|---|
| Ozempic | Semaglutide | Weekly injection | ~10-15% | R2,700-R3,100 |
| Wegovy | Semaglutide | Weekly injection | ~14-17% | Not registered |
| Mounjaro | Tirzepatide | Weekly injection | ~18-22% | R3,000-R6,000 |
Efficacy figures from published phase-3 trial data (STEP, SURMOUNT). SA pricing as of Q1 2026. Ozempic and Mounjaro are registered for type 2 diabetes in SA; use for weight loss is off-label.
Efficacy
Tirzepatide (Mounjaro / Zepbound) produces the largest average weight loss in head-to-head data — typically 18 to 22 percent of starting body weight over 72 weeks. Semaglutide at the higher Wegovy dose comes second at 14 to 17 percent. Ozempic at standard diabetes doses produces around 10 to 15 percent. Individual variation is wide.
Side effects
The side-effect profile is broadly similar across all three — nausea, fatigue, vomiting, constipation, and diarrhoea, worst during dose escalation. Tirzepatide tends to produce slightly more GI complaints at peak dose. Semaglutide tends to produce more reports of fatigue. Both produce the "Ozempic face" appearance with rapid weight loss.
Cost and access
South Africa. Ozempic is registered for type 2 diabetes only and used off-label for weight loss. Wegovy is not yet registered. Mounjaro is registered for diabetes only. Compounded semaglutide and tirzepatide are widely used to circumvent the cost barrier — R1,000 to R2,500 per month from a compounding pharmacy versus R3,000+ for the branded product.
United States. Wegovy and Zepbound are FDA-approved for weight management. Insurance coverage varies — many plans cover weight-management indications only for BMI ≥30 (or ≥27 with comorbidity).
European Union. Wegovy is available in most EU countries; access varies by country. Oral semaglutide (Wegovy pill) was submitted to the EMA in H2 2025.
Muscle preservation
None of the three drugs preserve muscle by themselves. Without intervention, all three produce 25 to 40 percent lean mass loss as a proportion of total weight loss. With a structured protein and resistance training plan, that figure drops dramatically across all three. The choice of drug is less important for muscle preservation than your daily habits.
Which should I take?
This is a decision for you and your prescriber. The trade-offs above are inputs — your access, your insurance or medical aid, your tolerance for side effects, and your medical history are all factors. Muscle Guard supports all three drugs (plus Rybelsus, Saxenda, Zepbound, and compounded preparations) identically.
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