Weight Loss

GLP-1 and GIP Weight Loss Medications: How These Treatments Help With Obesity

0

GLP-1 and GIP weight loss medications have changed how doctors treat obesity. These medicines work with the body’s own appetite and blood-sugar hormones, and when they are prescribed and monitored properly they can help people lose weight and improve their metabolic health. This article explains what they are, how the newer dual and triple receptor treatments differ, who they may suit, and the side effects worth knowing before you consider one.

Table of contents

What are GLP-1 receptor agonists?

GLP-1 stands for glucagon-like peptide-1, a hormone your gut makes naturally after you eat. It regulates several important processes in the body:

  • Signals the brain that you feel full
  • Slows the rate at which the stomach empties
  • Stimulates insulin release when blood sugar rises
  • Reduces glucagon, a hormone that raises blood sugar

GLP-1 receptor agonist medicines mimic this natural hormone and amplify its effects. That leads to reduced appetite, lower calorie intake, better blood-sugar control, and gradual, sustained weight loss. Several of these medicines are now widely used for both type 2 diabetes and weight management. The most common examples are:

  • Semaglutide (brand name Wegovy)
  • Tirzepatide (brand name Mounjaro)
  • Liraglutide (brand names Saxenda or Victoza)

These medicines have shown significant results in clinical studies, with many patients achieving meaningful weight loss when treatment is combined with lifestyle changes.

Dual and multi-receptor therapies (GLP-1 and GIP)

Research has moved beyond traditional GLP-1 medicines. Newer drugs target more than one metabolic receptor, which may produce greater effects on weight and blood sugar. A dual GLP-1 and GIP receptor agonist, such as tirzepatide, stimulates both GLP-1 receptors and GIP (glucose-dependent insulinotropic polypeptide) receptors. This dual action may improve insulin sensitivity and enhance weight loss, and some studies have shown greater average weight reduction with dual-receptor medicines than with single GLP-1 medicines.

Triple-receptor therapies (under development)

Researchers are also developing medicines that activate three targets at once: GLP-1, GIP and glucagon receptors. These metabolic therapies may further affect fat metabolism and energy balance, but they are still being studied and are not yet available in South Africa.

Benefits of GLP-1 and related therapies

When prescribed and monitored by a doctor, these medicines may help patients achieve:

  • Significant weight loss
  • Improved blood-sugar control
  • Reduced cardiovascular risk
  • Lower blood pressure in some patients
  • Improved metabolic health

GLP-1 receptor agonists are already widely used for type 2 diabetes and weight management, and ongoing research suggests they may have benefits beyond these conditions. Scientists are studying their effects on fatty liver disease (NAFLD and NASH), polycystic ovary syndrome (PCOS), addiction and impulse-control disorders, neurodegenerative diseases, and inflammatory bowel disease. This research is early, so these are areas of study rather than approved uses.

Who may benefit from GLP-1 therapy for weight management?

A doctor may consider GLP-1 or similar receptor therapies for patients who:

  • Are overweight (a BMI of 27 or more, with weight-related health risks)
  • Have obesity (a BMI of 30 or more)

A medical consultation is important to work out whether this treatment is appropriate for you, because these medicines are not right for everyone.

Possible side effects

Like all medicines, GLP-1 therapies can cause side effects. The common ones include nausea, reduced appetite, stomach discomfort, and constipation or diarrhoea. These are often mild and settle as the body adjusts. Doctors usually start with a low dose and increase it slowly to reduce side effects.

Serious but uncommon side effects include:

  • Pancreatitis. Symptoms can include severe abdominal pain, nausea and vomiting.
  • Gallbladder problems. Rapid weight loss can raise the risk of gallstones or gallbladder inflammation in some people.
  • Kidney complications. Severe vomiting or dehydration can worsen kidney function, particularly in people who already have kidney disease.
  • Severe gastrointestinal symptoms. In rare cases, patients have persistent vomiting, severe abdominal pain, or significant digestive symptoms.
  • Thyroid tumours. GLP-1 medicines carry a precaution about a rare type of thyroid tumour seen in animal studies. They are generally not recommended for people with a personal or family history of medullary thyroid carcinoma or MEN 2 (multiple endocrine neoplasia type 2).

Getting treatment in South Africa

GLP-1 and GIP weight loss medications are prescription-only in South Africa, which means a doctor has to assess you before one can be prescribed. A doctor reviews your medical history, current health and treatment goals, and screens for the cautions above, and only then decides whether a medicine is appropriate and at what dose. It is worth reading more about how the options compare in our guide on which weight-loss treatment is right for you, and about the risks of unregistered products in our note on compounded GLP-1 medications.

If you think this treatment may be right for you, you can read more about tirzepatide for weight management. An HPCSA-registered doctor will review your history and health, and if it is clinically appropriate, a prescription can be issued. GLP-1 and other receptor-based therapies are used in metabolic medicine, and combined with healthy lifestyle changes they can help people improve their metabolic health.

FAQ

How much weight can patients lose with GLP-1 medications?

Weight loss varies from person to person. Clinical studies have shown that some patients lose 5 to 15 percent of their body weight when GLP-1 medicines are combined with healthy lifestyle changes such as an improved diet and regular exercise.

How long does it take for GLP-1 medications to work?

Many patients notice reduced appetite within the first few weeks. Meaningful weight loss usually develops gradually over several months as the dose is increased and maintained.

Are GLP-1 medications safe?

GLP-1 medicines have been widely studied and are generally considered safe when prescribed and monitored by a healthcare professional. Like all medicines they can cause side effects, most commonly nausea or digestive discomfort when first starting. Read the medicine leaflet for full information and side effects.

Do GLP-1 medications require injections?

In South Africa these medicines are given as once-weekly or daily injections using pre-filled pens. Newer oral GLP-1 medicines are available in some regions outside South Africa.

Will the weight return if the medication is stopped?

Weight can return if treatment stops, particularly if lifestyle changes are not maintained. GLP-1 medicines are often used as part of a long-term weight-management plan under medical supervision.

Can I get GLP-1 medication online?

Patients may be able to get a GLP-1 prescription after a consultation, if they meet the medical criteria. A doctor assesses your medical history, current health and treatment goals before prescribing.

Do I still need to follow a diet and exercise plan while using GLP-1 medications?

Yes. GLP-1 medicines work best alongside healthy lifestyle changes, including balanced nutrition, physical activity, and long-term changes to habits.

Are there newer medications similar to GLP-1 therapies?

Yes. Researchers are developing metabolic therapies that act on several hormone receptors, such as GLP-1, GIP and glucagon. These are being studied for weight management and metabolic health.

Are compounded GLP-1 therapies safe?

Compounded GLP-1 medicines are not approved or registered medicines and may not undergo the same quality, safety and regulatory checks as licensed products. Only registered, approved GLP-1 medicines such as Wegovy, Mounjaro, Saxenda and Victoza should be used, because they have undergone proper clinical testing and regulatory review.

What is the difference between Ozempic and Wegovy?

Both contain semaglutide, but they are approved for different uses in South Africa. Ozempic is registered mainly for type 2 diabetes. Wegovy is registered specifically for weight management in people with obesity or weight-related medical conditions.

Medically reviewed by a South African HPCSA-registered medical practitioner. Last reviewed: July 2026.

This article is general health information, not medical advice or a prescription. The medicines named here are prescription-only; a prescription requires a consultation and clinical assessment. Speak to a doctor about what is appropriate for you.

Sources: SAHPRA, NHS, World Health Organization.

Back to list
Older Endometriosis Treatment in South Africa

Leave a Reply

Your email address will not be published. Required fields are marked *