Semaglutide

POPULAR 2026 | RESEARCH LIBRARY

Semaglutide

An evidence-based, plain-language information page covering approved uses, weight and metabolic outcomes, product differences, important risks and the South African regulatory context.

Contents

What semaglutide is

Important information and disclaimer

Approved and researched uses

Potential future uses

How it works

What evidence has found

South African regulatory context

How products compare

Risks and uncertainties

Treatment and measurement safeguards

Common questions

Join for updates

Sources

Important information and disclaimer

This page is for general education. Semaglutide is a prescription medicine when supplied as an authorised product and must be selected, prescribed and monitored for the correct indication by an appropriately qualified healthcare professional. This page does not diagnose diabetes, obesity, cardiovascular, kidney or liver disease and does not provide personal dosing, injection, switching or weight-loss instructions.

Ozempic, Wegovy and Rybelsus are product names with different authorised indications, formulations and instructions. A vial, cartridge or tablet sold online as ‘semaglutide’, ‘GLP-1’, ‘research grade’ or ‘generic Ozempic’ is not thereby equivalent to a registered medicine. Identity, peptide content, purity, sterility, excipients, absorption technology, stability and cold-chain history may be unknown.

Persistent severe abdominal pain, repeated vomiting, inability to keep fluids down, symptoms of dehydration, sudden visual change, severe allergic symptoms or collapse requires urgent medical assessment. People using insulin or medicines that can cause hypoglycaemia need professional coordination; semaglutide is not insulin and must not replace insulin in type 1 diabetes.

What is semaglutide?

Semaglutide is a long-acting analogue of human glucagon-like peptide-1 (GLP-1). Its sequence is modified to resist enzymatic breakdown and bind albumin, extending exposure sufficiently for weekly injectable products. Special tablet formulations use an absorption enhancer to permit a small and variable fraction to cross the stomach lining.

Names and products that must not be confused

What is semaglutide approved or researched for?

Authorised uses differ by product and jurisdiction. In the United States, current labels include type 2 diabetes, chronic weight management in defined adults and adolescents, and selected cardiovascular and kidney risk-reduction indications. Wegovy also has an accelerated-approval indication for noncirrhotic MASH with moderate to advanced fibrosis in adults. South African indications must be checked against the locally registered product information rather than copied from a foreign label.

Glycaemic control in adults with type 2 diabetes

Long-term body-weight reduction and maintenance in eligible people

Reduction of major cardiovascular events in specified high-risk populations

Reduction of kidney-disease progression and cardiovascular death in specified adults with type 2 diabetes and chronic kidney disease

Noncirrhotic MASH with F2-F3 fibrosis under a product-specific accelerated approval

Effects on appetite, food intake, cardiometabolic risk markers and weight-related complications

These indications are not interchangeable. Evidence for a branded formulation, population and outcome does not prove that an unregistered vial or a different formulation provides the same benefit.

Other potential uses—only if future research confirms them

Research continues in heart failure related to obesity, osteoarthritis symptoms linked to weight, metabolic liver disease, sleep apnoea, addiction-related behaviour, neurodegenerative disease and other complications of obesity. Some signals may be indirect consequences of weight loss or improved metabolic health rather than a separate disease-modifying action.

Promising exploratory findings should not be converted into off-label promises. Future use requires indication-specific trials that establish who benefits, how much benefit is clinically meaningful, what happens after discontinuation, and whether risks differ in older people, adolescents or those with complex disease.

How does semaglutide work?

GLP-1 receptor signalling

Semaglutide activates the GLP-1 receptor. In glucose-dependent fashion it increases insulin secretion and lowers inappropriate glucagon secretion, helping reduce blood glucose when glucose is elevated. This glucose dependence lowers—but does not eliminate—hypoglycaemia risk, especially when insulin or sulfonylureas are also used.

Appetite and energy intake

GLP-1 pathways in the brain and gut contribute to earlier fullness, reduced hunger and lower energy intake. Weight loss develops over time and varies widely. The medicine does not selectively remove only visceral fat, and preservation of muscle and nutritional quality remains important during substantial weight loss.

Gastric emptying and long exposure

Semaglutide can delay gastric emptying, particularly early in treatment, which contributes to gastrointestinal effects and may affect the timing or absorption of some oral medicines. Albumin binding and resistance to breakdown create a long half-life; this also means adverse effects may take time to resolve.

What has evidence found?

Type 2 diabetes and cardiovascular outcomes

The SUSTAIN programme established glucose-lowering efficacy and characterised injectable semaglutide in type 2 diabetes. Cardiovascular-outcome evidence supports risk reduction in defined populations, while the FLOW trial supports kidney and cardiovascular benefit in adults with type 2 diabetes and chronic kidney disease. These are outcome data for regulated treatment, not proof for informal compounded or research products.

Weight management

The STEP programme found substantial average weight loss with obesity-dose semaglutide alongside lifestyle intervention, but individual response varied and gastrointestinal discontinuation occurred. Weight regain after stopping treatment has been observed, showing that obesity commonly requires a long-term management plan rather than a short course.

Cardiovascular disease without diabetes

SELECT showed fewer major cardiovascular events in adults with established cardiovascular disease and overweight or obesity who did not have diabetes. The result broadened the clinical importance of obesity treatment but does not mean semaglutide is appropriate for every person seeking weight loss.

MASH and fibrosis

A Wegovy indication for noncirrhotic MASH with moderate to advanced fibrosis received US accelerated approval based on improvement in liver histology. Continued approval may depend on confirmation of clinical benefit. This is not an approval for ordinary fatty liver, cirrhosis or unsupervised weight-loss use.

Evidence and regulatory position in 2026

Current South African context

SAHPRA and the South African Pharmacy Council warned in 2026 about unlawful manufacture and supply of unregistered GLP-1/GIP medicines. Registered semaglutide products and their approved indications should be verified in the SAHPRA databases and professional information. Foreign approvals, online advertising or a laboratory certificate do not by themselves authorise manufacture, compounding, importation, prescribing, dispensing or sale in South Africa.

Demand and shortages create incentives for counterfeit, diverted and incorrectly compounded products. A legitimate prescription does not validate an unknown supplier. Patients should obtain the exact registered product through lawful channels and report suspected adverse reactions or falsified products through appropriate healthcare and regulatory routes.

How semaglutide products and related medicines compare

Known risks, contraindications and uncertainties

The exact warnings depend on product and jurisdiction. Current US labels carry a boxed warning about thyroid C-cell tumours seen in rodents; human relevance is unknown. They contraindicate use with a personal or family history of medullary thyroid carcinoma or MEN2, and with serious hypersensitivity to the product.

Nausea, vomiting, diarrhoea, constipation and abdominal pain are common; gastrointestinal reactions can be severe.

Acute pancreatitis has been observed; persistent severe abdominal pain requires urgent assessment.

Vomiting and diarrhoea can cause dehydration and acute kidney injury.

Gallstones and gallbladder inflammation can occur, especially with substantial or rapid weight loss.

Rapid glucose improvement may temporarily worsen diabetic retinopathy in susceptible patients.

Hypoglycaemia risk increases when combined with insulin or insulin secretagogues.

Delayed gastric emptying creates peri-anaesthetic aspiration concerns; the procedure team must know about GLP-1 treatment.

Pregnancy, breastfeeding, severe gastroparesis and complex medicine interactions require individual professional assessment.

Loss of lean mass can accompany weight loss; adequate nutrition and resistance activity should be considered clinically.

Treatment and measurement safeguards

This page deliberately does not provide a dose-escalation schedule, pen-click conversion, syringe-unit conversion, vial reconstitution method, switching equation or compounded-product recipe. Different brands, routes and strengths are not safely interchangeable by visual appearance, volume, “units”, clicks or milligrams alone.

Appropriate care may include confirming the indication and exact product, baseline glucose status, kidney and liver disease, retinopathy history, gallbladder or pancreatic history, other glucose-lowering medicines, pregnancy plans, nutritional risk and upcoming anaesthesia. Monitoring should focus on clinical benefit, adverse effects, hydration, glycaemia and preservation of function—not weight alone.

Common questions

Is Ozempic the same as Wegovy?

They contain semaglutide but are separately authorised products with different indications, presentations and instructions.

Is semaglutide insulin?

No. It is a GLP-1 receptor agonist and must never replace required insulin in type 1 diabetes.

Can an online vial be called generic Ozempic?

A name or assay claim does not establish equivalence, registration, sterility, formulation or lawful supply.

Does everyone lose the same amount of weight?

No. Average trial results hide wide individual variation, intolerance, discontinuation and regain after stopping.

Can tablets and injections be converted milligram-for-milligram?

No. Route-specific absorption and formulation make direct conversion unsafe outside authorised instructions.

What should happen before surgery?

The anaesthetist and procedure team should be told about GLP-1 treatment because gastric emptying may be delayed.

Is semaglutide registered in South Africa?

Registered-product and indication status should be confirmed in current SAHPRA records; unregistered GLP-1 manufacture and supply have been the subject of enforcement warnings.

Join for research and regulatory updates

Join the future research bulletin for label changes, cardiovascular, kidney and liver outcomes, South African regulatory updates and product-safety alerts. Subscription does not provide medical advice, prescriptions, product supply or personal dosing instructions.

Consent wording for the future form: “I agree to receive evidence and regulatory updates by email. This service does not provide medical advice, personal dosing instructions or product supply.”

Sources and further reading

US Food and Drug Administration. Ozempic (semaglutide) injection prescribing information. Revised May 2026.

US Food and Drug Administration. Wegovy (semaglutide) injection and tablet prescribing information. Revised 2026.

US Food and Drug Administration. Rybelsus and Ozempic tablets prescribing information. Revised January 2026.

SAHPRA and South African Pharmacy Council. Crackdown on unlawful manufacturing of unregistered GLP-1/GIP medicines. 2026.

Marso SP, et al. Semaglutide and cardiovascular outcomes in patients with type 2 diabetes. New England Journal of Medicine. 2016.

Wilding JPH, et al. Once-weekly semaglutide in adults with overweight or obesity. New England Journal of Medicine. 2021.

Lincoff AM, et al. Semaglutide and cardiovascular outcomes in obesity without diabetes (SELECT). New England Journal of Medicine. 2023.

Perkovic V, et al. Effects of semaglutide on chronic kidney disease in patients with type 2 diabetes (FLOW). New England Journal of Medicine. 2024.

Rubino D, et al. Weight regain and cardiometabolic effects after withdrawal of semaglutide. Diabetes, Obesity and Metabolism. 2022.

Editorial method: current regulator labels and South African regulatory notices were prioritised, then large randomised outcome trials. Product-specific indications were kept separate from molecule-level claims. Review after major label or regulatory changes, and no later than March 2027.