Glucagon-like peptide-1 (GLP-1) receptor agonists are medications, mostly self-injected, which were initially formulated and marketed for the treatment of diabetes and are now being increasingly used for weight loss.
They work by mimicking the action of the hormone glucagon-peptide 1, which regulates blood sugar levels. They stimulate the pancreas to release insulin when blood sugar is high, especially after meals, and supress the release of glucagon, a hormone that raises blood sugar.
They also affect the brain regions that control appetite, reducing hunger and increasing feelings of fullness, and slow the rate at which the stomach empties, inhibiting its peristalsis while increasing the contraction of the pyloric region, adding to the sense of fullness and potentially affecting the way the body processes food, according to a study in the journal Diabetes and Metabolism.
What are the common name brands for GPL-1s?
The best-known of the new GLP-1 agonists is semaglutide, sold internationally: Ozempic for treatment of type 2 diabetes in adults and to reduce risk of cardiovascular events, and Wegovy for weight loss.
“Wegovy has been officially launched as of August 16 [2025],” says Dr Angela Murphy, a specialist physician in Gauteng with a particular interest in endocrinology, diabetes and obesity. To date, many general practitioners have been prescribing Ozempic and other GLP-1s off-label for weight loss.
“The newest agent in the incretin class is tirzepatide, which is a GLP-1/GIP (gastric inhibitory polypeptide) agonist,” she says. “By acting at two receptors, it has shown even greater benefit with glucose control and weight loss.” Tirzepatide is sold as Mounjaro for type 2 diabetes, and Zepbound for weight loss. “Mounjaro is registered in South Africa for diabetes, and registration for obesity treatment is imminent. Zepbound is not available here.”
Liraglutide is another agonist marketed in two formulations, registered and sold in South Africa: Saxenda for weight management (until August 2025, the only GLP-1 agonist registered here specifically for weight loss), and Victoza for diabetes. “Liraglutide is also now available as a first generic, Giliptra, which has type 2 diabetes registration,” says Dr Murphy. “This product is 20% cheaper than the originator.” Two other agonists are registered for diabetes: dulaglutide (brand name Trulicity) and lixisenatide (brand name Soliqua, which is a combination of lixisenatide and insulin glargine).”
Who are GPL-1s for?
GLP-1 agonists are at present primarily intended for adults with type 2 diabetes – the country’s leading killer of women and second most common underlying cause of death overall, according to diabetes specialist nurse Michael Brown, head of the CDE (Centre for Diabetes and Endocrinology) Academy.
They are also being used for people with obesity, which is a major contributor to diabetes – half of all adults in South Africa are overweight or obese, reports Dr Micheal Kofi Boachie, a researcher at the SAMRC/WITS Centre for Health Economics and Decision Science. Around 12 million South Africans suffer from weight-related conditions for which they receive treatment in the public sector, including not only diabetes, but hypertension, cardiovascular disease, arthritis and certain cancers – diseases that cause life-long illness, disabilities and premature death.
Boachie and colleagues have calculated that overweight and obesity cost the health system around R33 billion a year, with an annual per person cost of around R2,769. It is against this that costs of a solution such as a GLP-1 agonists need to be weighed.
How expensive are GLP-1 drugs?
In South Africa GLP-1 agonists are currently inaccessible for many because of the expense – around R1,200 to R5,000 or more a month, depending on the medication and dosage, despite a public health need. The World Health Organisation is currently considering recommending them in their global guidelines as essential treatments for diabetes and obesity care.
In an editorial in 2024 in the South African Medical Journal, Dr Nomathemba Chandiwana and Professor Francois Venter of the Ezintsha Research Centre at Wits urge simplification of access to these mediations, as well as generic manufacture to facilitate price reduction.
How safe are they?
“There is no magic bullet for weight loss,” says Johannesburg-based dietitian Lila Bruk. “To determine if you’re a suitable candidate for GLP-1 agonists, it’s important to see your health care practitioner.” Like all medications, they have drawbacks. Side effects may include nausea, indigestion, bloating, and less commonly, vomiting and diarrhoea, although these can be reduced by eating small portions, avoiding fatty meals and chewing food well, and are generally short-lived.
A bigger drawback, says Bruk, is that these drugs may need to be used long-term to keep weight off, and it is too early to know the effects of long-term use.
How effective are they?
“There’s no doubt GLP-1 receptor agonists offer the best medical intervention to date for overweight and obesity,” says Dr Murphy. “If used as part of a holistic approach to a healthy lifestyle, with sensible eating and regular exercise, significant sustained weight loss may be achieved.”
It is crucial that GLP-1s be taken under medical supervision and obtained on prescription through reputable sources. The South African Health Products Regulatory Authority recently warned about “the proliferation of falsified, compounded and substandard GLP-1-containing products being made available via websites, social media and other informal channels. They pose a health risk to the public.”
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