Mounjaro vs Ozempic vs Wegovy — the comparison

Tirzepatide (Mounjaro / Zepbound) produces the largest average weight loss of the three — typically 18 to 22 percent of starting body weight over 72 weeks.[²] Semaglutide at the Wegovy dose comes second at 14 to 17 percent. Ozempic at standard diabetes doses produces around 10 to 15 percent. None of the three preserves muscle by itself — the protein-and-training playbook decides that.

At a glance

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 healthcare provider. 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.

Muscle Guard is a self-tracking companion and coach. Not a medical device. Not medical advice. Always consult your healthcare provider for personal decisions.