The arrival of medicines such as semaglutide and tirzepatide has changed the conversation about obesity treatment.

For many South Africans, there is now another important option between trying to lose weight through lifestyle changes alone and considering metabolic or bariatric surgery.

But does this mean bariatric surgery is becoming unnecessary?

No.

The more useful question is not:

“Medication or surgery?”

It is:

“Which treatment, or combination of treatments, is most appropriate for my health, my degree of obesity, my medical conditions and my long-term goals?”

That distinction matters because obesity is a chronic disease, and different patients require different levels of treatment.

First, obesity treatment is not simply about losing kilograms

Successful obesity treatment should not be judged only by the number on the scale.

Your healthcare team should also be considering whether treatment can improve conditions such as:

type 2 diabetes;
high blood pressure;
obstructive sleep apnoea;
abnormal cholesterol or other blood fats;
cardiovascular disease;
fatty liver disease;
mobility and physical functioning; and
your overall quality of life.

South Africa now has its own adult obesity clinical practice guideline, developed specifically for the South African healthcare environment. It recognises obesity as a chronic disease requiring appropriate medical management rather than simply telling patients to “eat less and exercise more”.

What weight-loss medicines are available in South Africa?

Two of the medicines receiving the most attention are semaglutide and tirzepatide.

Wegovy: semaglutide

SAHPRA-approved patient information states that Wegovy is registered for weight management, together with dietary changes and physical activity, in adults with:

a BMI of 30 kg/m² or higher; or
a BMI from 27 kg/m² to below 30 kg/m² together with a weight-related health condition such as diabetes, hypertension, abnormal blood fats, obstructive sleep apnoea or cardiovascular disease.

Mounjaro: tirzepatide

Mounjaro is also registered by SAHPRA for weight management in adults with:

a BMI of 30 kg/m² or higher; or
a BMI from 27 kg/m² to below 30 kg/m² with at least one weight-related condition such as hypertension, abnormal blood fats, obstructive sleep apnoea, cardiovascular disease, prediabetes or type 2 diabetes.

These are prescription medicines. Being above a particular BMI does not automatically mean that one of these medicines is suitable for you. Your medical history, other medication, diabetes treatment, pregnancy plans and potential side effects all need to be considered.

How effective are these medicines?

Modern obesity medicines can produce substantial weight loss, and newer medicines are considerably more effective than many older weight-loss drugs.

The original evidence review on which this article is based highlighted clinical trials in which tirzepatide achieved mean weight losses around 20% in some study populations. It also made an important distinction between the results achieved in tightly controlled clinical trials and what patients may achieve in everyday clinical practice.

This is one reason patients should avoid interpreting a headline such as “20% weight loss” as a promise of what will happen to them.

Your response may be greater or smaller.

The important issue patients often don’t hear about: what happens when you stop?

Obesity medicine is generally not intended to function like a short course of antibiotics where you take the medicine, finish the course and expect the underlying problem to have disappeared.

For many patients, obesity requires long-term management.

Studies of GLP-1-based treatment have shown significant weight regain in many people after medication is discontinued. The evidence reviewed in the original article therefore describes continued treatment as an important part of the discussion patients should have before starting therapy.

That does not mean every patient must remain on exactly the same medicine or dose forever.

It means you should ask your doctor:

“What is the long-term plan if this medication works for me?”

That conversation should include effectiveness, side effects, affordability and what happens if treatment is interrupted.

So where does bariatric surgery fit?

Metabolic and bariatric surgery remains one of the most effective treatments available for severe obesity.

The 2025 South African obesity guideline recommends metabolic and bariatric surgery for people with a BMI above 35 kg/m², regardless of whether obesity-related medical conditions are present.

Surgery should also be considered in appropriately selected patients with a BMI of 30–34.9 kg/m² and metabolic disease.

This is important because many South Africans may still believe that surgery is only available when BMI is over 40, or only after every possible diet and medication has failed.

Current clinical guidance is broader than that.

Your medical scheme’s funding criteria may not necessarily be identical to the clinical criteria, so clinical eligibility and medical-scheme authorisation should be considered separately. South African patient guidance also notes that funders may apply higher BMI thresholds than the clinical guideline.

How much weight can bariatric surgery produce?

According to the South African obesity guideline, metabolic and bariatric surgery combined with healthy behaviours can result in approximately 20% to 40% long-term total body-weight loss, depending on the patient and procedure.

It can also substantially improve obesity-related diseases including:

type 2 diabetes;
obstructive sleep apnoea;
hypertension; and
fatty liver disease.

This does not mean every surgical patient loses 20–40%, nor does surgery make somebody permanently immune to weight regain.

The original evidence review notes that weight recurrence can occur after bariatric surgery as well. The difference is that surgery produces a substantial and durable metabolic intervention for many patients, and weight recurrence can often be treated rather than automatically being regarded as failure.

Is bariatric surgery dangerous?

It is major surgery and must be treated as such.

There are anaesthetic risks, bleeding, infection, leaks, blood clots and procedure-specific complications that should be explained to you individually.

At the same time, modern laparoscopic metabolic and bariatric surgery performed in an appropriate setting should not be confused with the bariatric surgery of several decades ago.

The South African guideline reports that, for most patients, laparoscopic surgery is associated with a mortality rate below 0.1% and a serious complication rate below 5%. These are population-level figures and cannot predict an individual patient’s risk.

Your individual risk depends on factors including your age, BMI, heart and lung health, diabetes, smoking or nicotine use, previous surgery and other medical conditions.

Surgery is also not a “quick fix”

Bariatric surgery changes anatomy, but successful treatment still requires long-term participation from the patient.

The South African guideline describes surgery as the beginning of a lifelong journey.

Before surgery, patients usually undergo multidisciplinary assessment of their:

medical health;
nutritional status;
psychological or mental health;
functional status;
diabetes and other chronic conditions;
possible sleep apnoea; and
readiness for long-term follow-up.

After surgery, lifelong medical and nutritional follow-up is important.

Depending on the procedure, this can include monitoring vitamin and mineral levels, taking supplements, maintaining adequate protein intake and attending regular follow-up appointments.

So which is better: medication or surgery?

There isn’t one answer for every patient.

Medication may be appropriate when:

you qualify medically for pharmacological obesity treatment, prefer a non-surgical approach, have obesity-related health risks that may improve with weight loss and are able to continue treatment and appropriate medical follow-up.

Surgery deserves serious consideration when:

you have severe obesity, particularly when a large and durable reduction in weight is needed to improve your health, or when conditions such as type 2 diabetes, sleep apnoea, hypertension or other metabolic disease make effective long-term treatment particularly important.

South African guidance specifically recommends surgery at BMI above 35 kg/m² and consideration of surgery at BMI 30–34.9 kg/m² in patients with metabolic disease.

And sometimes the answer is both.

The old idea that medication and surgery are competing treatments is becoming outdated.

Medication can be used:

before surgery in selected patients;
as part of broader obesity management;
after surgery if clinically appropriate; or
to help manage recurrent weight gain following bariatric surgery.

The original evidence review specifically identifies GLP-1-based treatment after bariatric surgery as an increasingly important management option for patients experiencing weight recurrence.

The treatment journey can therefore look more like:

medical assessment → lifestyle and nutritional treatment → medication and/or surgery → long-term obesity management

rather than a competition between injections and surgery.

What are the side effects of weight-loss injections?

These medicines are effective, but they are not risk-free.

With semaglutide, very common reported effects include:

nausea;
vomiting;
diarrhoea;
constipation;
abdominal pain;
headache; and
tiredness or weakness.

Gallstones are also listed, and severe persistent abdominal pain requires urgent assessment because pancreatitis is a recognised serious adverse effect.

Tirzepatide can similarly cause gastrointestinal symptoms including nausea, vomiting, diarrhoea, abdominal discomfort and constipation. Its South African product information also warns about pancreatitis, dehydration and increased hypoglycaemia risk when it is combined with certain diabetes medicines such as insulin or sulphonylureas.

Patients with diabetes should therefore not adjust insulin or other diabetes medication themselves when starting obesity medication.

Pregnancy requires special consideration

Women who are pregnant, planning pregnancy or breastfeeding should specifically discuss these medicines with their doctor.

The South African Wegovy patient leaflet states that it should not be used during pregnancy and recommends stopping semaglutide at least two months before a planned pregnancy.

The current South African Mounjaro product information states that tirzepatide is not recommended during pregnancy and should be discontinued at least one month before a planned pregnancy.

Do not stop prescribed medication without discussing it with the clinician responsible for your care, but pregnancy planning needs to form part of the treatment conversation.

A particularly important warning for South African patients

Do not buy semaglutide, tirzepatide or supposed “GLP-1” injections from social media sellers, informal websites or unverified suppliers.

SAHPRA has repeatedly warned South Africans about falsified, illegally compounded and substandard GLP-1 products.

This is not a theoretical concern.

In July 2026, SAHPRA, the South African Pharmacy Council and the Health Professions Council of South Africa issued a public warning concerning recalled iDEXIS Semaglutide, iDEXIS Tirzepatide and iDEXIS Semaglutide/Tirzepatide products, which SAHPRA classified as posing a serious safety risk.

If you are considering one of these medicines, obtain it through a legitimate prescription and registered pharmacy.

Cost matters, but South African patients need South African numbers

US studies comparing the dollar cost of bariatric surgery with lifelong GLP-1 treatment cannot simply be converted into rands and presented as South African cost-effectiveness evidence.

South African medicine prices, medical-scheme benefits, hospital networks, surgical benefits and out-of-pocket costs are different and can change.

Before choosing treatment, ask for the total expected cost, not simply the cost of the first month.

For medication, ask about:

monthly medicine costs;
consultations;
blood tests;
dose escalation;
medical-scheme benefits;
what happens if your scheme stops funding the medicine; and
the likely cost over several years.

For surgery, ask about:

surgeon and assistant fees;
anaesthetist fees;
hospital costs;
dietitian and multidisciplinary-team costs;
medical-scheme authorisation;
possible co-payments;
follow-up consultations; and
lifelong vitamin and nutritional supplementation.

Comparing a once-off surgical quotation with one month’s medication price does not give you a meaningful long-term comparison.

Eight questions worth asking at your appointment

If you are considering medical or surgical treatment for obesity, ask your healthcare team:

How is my weight currently affecting my health?
What is my BMI, and is BMI alone giving us an adequate picture of my health risk?
Do I qualify clinically for obesity medication?
Should I also be evaluated for metabolic or bariatric surgery?
What amount of weight loss would meaningfully improve my particular medical conditions?
What are the risks, side effects and long-term commitments of each option?
If medication works, what is our long-term treatment plan?
If I choose one treatment now, does that prevent me from using another treatment later?

The last question is especially important.

In many cases, the answer is no.

Weight-loss injections have changed obesity treatment, but they have not ended the role of bariatric surgery.

South African patients now have more treatment options than they did only a few years ago.

For some people, medication may be an appropriate first treatment.

For others, particularly those living with severe obesity or important metabolic disease, delaying discussion of metabolic and bariatric surgery may mean delaying one of the most effective treatments available.

And for some patients, the best long-term answer may involve both medical and surgical treatment at different stages of the same journey.

The goal should not be to choose the most fashionable treatment.

It should be to choose the treatment strategy most likely to give you meaningful, safe and sustainable improvement in your health.

Patient information notice: This article provides general educational information and is not a diagnosis or personalised treatment recommendation. Obesity medication and metabolic or bariatric surgery require individual medical assessment. Do not start, stop or change prescription medication on the basis of this article. If you are considering treatment, discuss your health history, current medicines and treatment options with an appropriately qualified healthcare professional.

Weight-Loss Injections or Bariatric Surgery? What South African Patients Need to Know