For most of medicine's history, the options for treating obesity were limited and modest. Diet and exercise advice. A small handful of older medications with significant side effects and small effects. Bariatric surgery for severe cases. The newer class of GLP-1 and GIP/GLP-1 medications has changed that picture, and Mounjaro currently sits at the top of the class on weight management endpoints.
This page covers what tirzepatide is approved for in South Africa, who it suits, and what the trials show.
The SAHPRA Approved Use
From October 2025, Mounjaro is approved by SAHPRA as an adjunct to a reduced calorie diet and increased physical activity for chronic weight management in adults with:
- A BMI of 30 kg/m² or higher (obesity), or
- A BMI of 27 to 29.9 kg/m² with at least one weight related comorbidity, such as type 2 diabetes, hypertension, dyslipidaemia, obstructive sleep apnoea, or cardiovascular disease
This mirrors the indication in other regulated markets. The word 'chronic' matters. Obesity is officially recognised as a chronic medical condition, not a lifestyle issue. Mounjaro is treatment for that condition, not a tool for general weight loss in healthy weight people.
What The Trials Showed
The major weight management trial is called SURMOUNT-1. It enrolled over 2500 adults with obesity (without diabetes), followed them for 72 weeks, and compared three tirzepatide doses to placebo.
| Dose | Mean weight reduction at 72 weeks |
|---|---|
| Placebo | ~3.1% |
| Tirzepatide 5 mg | ~15.0% |
| Tirzepatide 10 mg | ~19.5% |
| Tirzepatide 15 mg | ~20.9% |
For context, these are averages across a large group. Individual results vary. Some people respond more strongly, some less so. About 50 percent of people on the higher doses lost 20 percent or more of their starting weight. Some people lose less. A small minority do not respond and treatment is reconsidered.
The Trial Also Tracked Other Health Markers
Weight is the headline number but not the only thing that improved in SURMOUNT-1 and other trials. Reductions were also seen in:
- Waist circumference
- Blood pressure
- Cholesterol levels
- Markers of cardiovascular risk
- HbA1c in people with pre-diabetes
- Sleep apnoea severity (in the SURMOUNT-OSA trial)
The point is that the benefit is broader than the scale. Many of the conditions that come with excess weight improve alongside it.
Who Mounjaro Suits Well
- Adults meeting the BMI criteria above
- People who have tried diet and exercise without sustained success
- People with weight related comorbidities where reduction would meaningfully improve health
- People who understand it is a long term treatment, not a short cycle
- People without contraindications (see below)
Who Mounjaro Does Not Suit
- People with a personal or family history of medullary thyroid carcinoma or MEN2 syndrome
- People with severe gastrointestinal disease, particularly gastroparesis
- People with a history of pancreatitis or active pancreatic disease
- People with active gallbladder disease (relative contraindication)
- Pregnant women or those actively trying to conceive
- People with type 1 diabetes (different mechanism, not indicated)
- People with severe kidney disease (caution, dose adjustment may be needed)
- People with a history of eating disorders (case by case, but requires careful assessment)
Find Out If You Qualify
An online consultation reviews your medical history against the eligibility criteria and works out whether Mounjaro is appropriate.
Start ConsultationRealistic Expectations
The first month
The 2.5 mg starting dose is below therapeutic level. Appetite changes are usually noticeable. Weight changes are usually modest. Side effects (mostly nausea) are common but tend to settle.
Months two to six
As the dose steps up, the effect typically strengthens. Weight reduction often progresses steadily, though not linearly. Side effects often improve as the body adapts, though they can flare with each dose increase.
Months six to twelve
Most of the trial weight reduction happens over the first 12 months. Many people reach their therapeutic dose and stay there.
Beyond twelve months
Treatment is continued long term. Stopping leads to weight regain over time, as the underlying appetite signalling returns to baseline. Discussions about long term continuation, dose adjustment, or in some cases tapering happen with the treating doctor.
Why Diet And Exercise Still Matter
Three reasons.
Mechanism. The medication reduces appetite. If you eat past the appetite reduction, the effect is muted. People who do not adjust their eating get smaller results.
Muscle preservation. Significant weight loss without resistance training causes lean mass loss. This is undesirable. Adequate protein intake and resistance exercise during treatment reduce this.
Long term health. Mounjaro improves several health markers, but eating quality and exercise still independently contribute. The combination is stronger than the medication alone.
What This Page Is Not
This page does not give calorie targets, weight goals, or 'how much you should aim to lose'. Those are individual decisions made between a person and their treating doctor based on starting weight, health status, and what is realistic and safe. Mounjaro is medical treatment for a medical condition. The goal is health improvement, not a number on a scale.
Related Reading
Frequently Asked
The largest clinical trial (SURMOUNT-1) studied people with obesity over 72 weeks. Mean weight reduction was around 15 percent at 5 mg, 19 percent at 10 mg, and 21 percent at 15 mg. Individual results vary considerably based on dose, adherence, diet, exercise, and biology.
Only while continuing treatment. Studies show that stopping the medication tends to lead to weight regain over time. Mounjaro is intended as a long term treatment for a chronic condition, not a short term solution.
Some lean mass loss is expected with any significant weight loss. Resistance training and adequate protein intake during treatment reduce this. Discuss with your treating doctor.
The SAHPRA indication specifically pairs Mounjaro with reduced calorie diet and increased physical activity. The medication makes eating less easier by reducing appetite, but the underlying calorie reduction is what produces weight loss.