The weight management indication is the newer of Mounjaro's two SAHPRA registrations. It was added in October 2025, ten months after the diabetes indication, on the back of the SURMOUNT trial programme. It is also the indication driving most of Mounjaro's growth in the South African market. By Aspen's own reporting, the weight management approval was the key catalyst for tirzepatide becoming the country's biggest selling medicine in November 2025.
This page is for people considering tirzepatide for weight management, whether or not they have type 2 diabetes.
The SAHPRA Approved Indication
Tirzepatide is approved as an adjunct to a reduced calorie diet and increased physical activity for chronic weight management in adults with:
- BMI of 30 kg/m² or higher (clinical obesity), or
- BMI of 27 to 29.9 kg/m² with at least one weight related comorbidity (type 2 diabetes, hypertension, dyslipidaemia, sleep apnoea, cardiovascular disease, polycystic ovary syndrome with metabolic features)
'Chronic' is the key word. The medication is treatment for a chronic condition. It works while you take it, and stopping leads to gradual return of the condition over the following year.
The SURMOUNT Trial Programme
SURMOUNT was the clinical programme that established tirzepatide for weight management. Five trials, over 5,000 participants, in various populations.
| Trial | Population | Mean weight reduction (15 mg) |
|---|---|---|
| SURMOUNT-1 | Adults with obesity, no diabetes | ~20% at 72 weeks |
| SURMOUNT-2 | Adults with obesity and type 2 diabetes | ~14% at 72 weeks |
| SURMOUNT-3 | Following intensive lifestyle intervention | ~22% at 72 weeks |
| SURMOUNT-4 | Continued vs withdrawal at 36 weeks | Continued: ~26%; Withdrawn: ~6% |
| SURMOUNT-5 | vs Semaglutide 2.4 mg head to head | ~20% (vs semaglutide ~14%) |
The pattern across trials is consistent. Tirzepatide produces around 15 to 22 percent average weight reduction depending on the population and trial structure. Around half of participants achieve 20 percent or more reduction. A detailed review of each trial lives here.
What Improves Alongside Weight
SURMOUNT measured many things beyond the scale. Notable findings:
- Waist circumference reduction proportional to weight loss
- Blood pressure reduction of around 6 to 8 mmHg systolic
- HbA1c reduction in those with elevated baseline
- Triglyceride and LDL cholesterol improvements
- Improvement in obstructive sleep apnoea severity
- Reduction in markers of liver fat in those with NAFLD
- Improvements in quality of life measures
- Reductions in pain and physical function scores in those with osteoarthritis
Weight is the headline number. The downstream effects on the whole metabolic and cardiovascular picture matter at least as much.
Find Out If You Qualify
An online consultation reviews your medical history and BMI against the SAHPRA eligibility criteria.
Start ConsultationRealistic Expectations
The first month (2.5 mg)
Below therapeutic dose. The body is adjusting. Appetite changes usually noticeable. Side effects (mostly nausea) common but usually manageable. Weight changes typically modest.
Months 2 to 5 (titration)
Dose stepping up through 5, 7.5, 10, 12.5, and potentially 15 mg. The effect strengthens. Most weight loss happens here. Side effects may briefly worsen with each step then settle.
Months 6 to 12 (maintenance)
Established at the dose that works for you. May be 15 mg or lower. The maintenance phase continues weight reduction at a slowing rate, with eventual stabilisation.
Beyond 12 months
Treatment continues. Stopping leads to weight regain. Decisions about long term continuation, dose reduction, or eventual cessation happen with the treating doctor.
The Lean Mass Question
Any significant weight loss includes some lean tissue loss. With tirzepatide producing larger total weight loss than older medications, the absolute amount of lean mass at risk is also larger. This is addressable with resistance training and adequate protein intake during treatment, but it does require attention.
Practical principles during weight loss on tirzepatide:
- Two to three resistance training sessions per week (real progression, not light circuits)
- Protein intake of around 1.6 to 2.2 g per kg of target body weight per day
- Adequate sleep and stress management
- Cardio for cardiovascular benefit, not as the priority for body composition
Without these, weight loss happens but with disproportionate lean mass loss. With them, the body composition outcome is substantially better.
What This Page Is Not
This page does not give specific calorie targets, diet plans, exercise prescriptions, or weight goals. Those decisions are individual and depend on starting weight, medical context, and what is sustainable. They belong in the conversation between you and a treating doctor. The medication's job is to make calorie reduction tolerable. The rest is contextual.
Frequently Asked
The SURMOUNT-1 trial showed average weight reduction of about 20 percent at the maximum 15 mg dose over 72 weeks. Individual results vary considerably and many people achieve different outcomes at lower doses.
Yes. The SAHPRA approved use is as an adjunct to a reduced calorie diet and increased physical activity. The medication reduces appetite which makes eating less easier, but the calorie reduction is still what produces weight loss.
On average, in head to head trials, yes. SURMOUNT-5 compared the two directly and tirzepatide produced larger mean weight reduction. Individual variation is wide. For many people the practical difference is smaller than the averages suggest.
The SURMOUNT-4 trial specifically studied this. Stopping tirzepatide led to substantial weight regain over the following year. The medication is intended as long term treatment for a chronic condition.