By Dr Bianca Crook, South African general
practitioner
Medically reviewed: 1 September 2026
Before starting a GLP-1 medicine, a patient should understand why it is being prescribed, what benefits are realistic, how treatment will be monitored, which side effects are common, and which symptoms need urgent attention. The medicine is one part of a longer treatment plan. It does not replace nutrition, movement, follow-up care or a plan for what happens if treatment is paused or stopped.
Key points
- Confirm the exact medicine, indication and follow-up plan with the prescriber.
- Tell the clinician about pregnancy plans, previous pancreatitis, gallbladder disease, severe digestive symptoms, kidney problems, diabetes medicines and upcoming procedures.
- Dose increases should follow the product information and the patient’s tolerance; reaching the highest dose is not the goal.
- Know the difference between expected digestive symptoms and warning signs.
- Use a registered product from a legitimate supply chain.
Start with the purpose, not the brand name
Medicines in this area include GLP-1 receptor agonists such as semaglutide and dual GIP/GLP-1 medicines such as tirzepatide. Brand names, approved uses and availability differ between countries. A medicine approved for type 2 diabetes is not automatically approved for weight management, even if the active ingredient is related.
Ask the prescriber: What condition are we treating? Why is this medicine appropriate for me? What would count as meaningful benefit? How and when will we review it? The answers should be individual. A prescription is not a promise of a particular number on the scale.
In South Africa, patients should also check that the product is registered and supplied through a legitimate pharmacy or authorised service. SAHPRA has warned about unregistered, compounded, substandard and falsified GLP-1 products. A suspiciously cheap injection, an informal social-media seller or a product without a traceable supply chain can create risks that have nothing to do with the normal medicine itself.
Share the history that can change the plan
A safe consultation needs more than weight and height. Tell the clinician about all prescription medicines, over-the-counter products and supplements. This is particularly important if you use insulin or a sulfonylurea, because the combination may increase the risk of low blood glucose and may require clinician-led adjustment.
Discuss severe or persistent stomach symptoms, previous pancreatitis, gallstones or gallbladder disease, kidney problems, eye complications from diabetes, and any personal or family history relevant to the medicine’s contraindications. Some GLP-1 products carry a boxed warning about thyroid C-cell tumours based on animal findings and are contraindicated in people with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2. The exact warning depends on the product, so the prescriber should check its current approved information.
Pregnancy deserves a direct conversation. Weight-loss medicines are not used to pursue weight loss during pregnancy. Product information also includes medicine-specific advice about stopping before a planned pregnancy. Do not guess the interval or stop treatment without discussing it with the prescriber.
Plan for eating, fluids and common symptoms
Nausea, diarrhoea, vomiting, constipation and abdominal discomfort are among the common adverse effects of semaglutide and tirzepatide products. They may be more noticeable during dose escalation. Smaller meals, slower eating and attention to hydration may help some people, but persistent symptoms need review.
Do not let reduced appetite quietly become inadequate nutrition. Discuss protein, fibre, fluids and resistance or strength activity appropriate to your circumstances. Rapid weight loss can include loss of lean tissue as well as fat. A plan that protects function and nutritional adequacy matters more than simply eating as little as possible.
Constipation is common but should not be dismissed when it is severe or accompanied by escalating abdominal pain, repeated vomiting, swelling or inability to pass stool or gas. Read Constipation on GLP-1 Treatment: What Is Common and When to Seek Help and GLP-1 Red Flags: Symptoms You Should Not Ignore before the first dose so that you know when to call.
Understand dose escalation
Starting doses are usually designed to improve tolerability, not to produce the maximum effect immediately. Escalation schedules are product-specific. A dose increase should not be treated as a reward, a competition or proof that treatment is working.
If symptoms are significant, the prescriber may decide to delay escalation, reassess the cause, review other medicines or use another approach. Do not accelerate the schedule, repeat a dose after vomiting, or use clicks or unapproved measurements unless the specific device instructions and prescriber support that method. See Why the GLP-1 Dose Is Not a Competition.
Make a long-term plan at the beginning
Obesity is a chronic, relapsing disease for many people. Trials of semaglutide and tirzepatide show that weight regain is common after withdrawal, although individual experiences vary. Before starting, ask how affordability, supply interruptions, side effects, pregnancy, surgery and future maintenance would be handled.
It is better to discuss those realities early than to act as though the first prescription is a complete plan. What Happens When GLP-1 Treatment Stops? explains why follow-up and maintenance planning matter.
For the full treatment journey - including dose decisions, nutrition, side effects, plateaus, pregnancy, surgery, maintenance and recurrence - see Before Your Next Injection.
Medical disclaimer: This article provides general education and does not diagnose a condition or replace individual medical care. Do not start, stop or change a prescription medicine without your healthcare professional. Seek urgent care for severe or rapidly worsening symptoms.
Sources: FDA Wegovy prescribing information; FDA Zepbound prescribing information; WHO GLP-1 therapies Q&A; SAHPRA warning on unregistered, compounded, substandard and falsified GLP-1/GIP products.