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Ozempic (semaglutide) has become one of the most talked-about weight loss medications in South Africa — and the world. It works, often dramatically. But along with the impressive results comes a side effect profile that every prospective user needs to understand before their first injection.
South Africans are spending thousands of rands per month on Ozempic and its weight-loss approved sibling Wegovy. Many are doing so without a full understanding of what the drug does to the body beyond shrinking the number on the scale. This guide covers everything — from the common and manageable to the rare but serious — so you can make an informed decision with your doctor.
Medical Disclaimer: Ozempic is a prescription medication. It should only be used under medical supervision. This article is for informational purposes only and does not constitute medical advice. Always consult a qualified doctor before starting, stopping, or adjusting any medication. If you experience severe symptoms, seek emergency medical care immediately.
How Ozempic Works (And Why It Causes Side Effects)
Ozempic is a GLP-1 receptor agonist. It mimics a natural gut hormone called glucagon-like peptide-1, which is released after eating. This hormone signals the brain that you're full, slows stomach emptying, reduces appetite, and lowers blood sugar by stimulating insulin release.
The side effects of Ozempic are almost entirely a direct consequence of these mechanisms — particularly the slowing of gastric emptying. When food moves through your digestive system more slowly than your body is used to, nausea, bloating, and digestive discomfort follow. The drug is working, but your digestive tract is adjusting to a new normal.
The Most Common Side Effects
These affect the majority of Ozempic users at some point, particularly during the dose escalation phase (the first 8–16 weeks):
1. Nausea — The Most Reported Side Effect
Up to 44% of clinical trial participants reported nausea on semaglutide. For most people it peaks in the first 4–8 weeks and improves as the body adapts. It tends to be worst after dose increases.
Management tips:
- Eat smaller meals — large portions overwhelm a slower-emptying stomach
- Avoid high-fat, greasy, or very spicy foods, especially in the first weeks
- Eat slowly and stop at the first sign of fullness
- Stay upright for at least 30 minutes after eating
- Ginger tea and plain crackers can help settle the stomach
- Inject in the evening so peak nausea occurs during sleep
2. Vomiting
Less common than nausea but affects roughly 24% of users. Usually accompanies nausea and follows the same escalation pattern. If vomiting is frequent or severe, your doctor may pause the dose increase or temporarily reduce your dose.
3. Diarrhoea and Constipation
The slowed digestion affects bowel habits differently in different people. Some experience loose stools and diarrhoea; others develop constipation. Both are common and generally improve over time.
For diarrhoea: Stay hydrated, avoid fatty foods, and discuss anti-diarrhoeals with your doctor if needed.
For constipation: Increase water and dietary fibre intake. Consider adding high-fibre foods like psyllium husks (available at most SA pharmacies) to your routine.
4. Bloating and Abdominal Discomfort
A feeling of fullness, gas, and abdominal pressure is very common. This often accompanies the nausea phase and resolves as digestion adapts. Eating more slowly and chewing thoroughly helps significantly.
5. Fatigue
Many users report feeling tired, particularly in the first few weeks. This is partly due to reduced calorie intake (your appetite drops significantly), and partly the body's adjustment to the medication. Ensure you are eating enough protein and maintaining adequate nutrition even as your appetite decreases — this is a common mistake that worsens fatigue.
6. Headaches
Reported by roughly 14% of users, headaches are often related to reduced food and fluid intake. Staying well-hydrated and maintaining regular (smaller) meals usually resolves them.
The "Ozempic Face" — Rapid Weight Loss and Appearance Changes
As Ozempic use became mainstream, a new phenomenon was widely reported: "Ozempic face" — facial volume loss, sagging, and an aged appearance that accompanies rapid weight loss. This isn't specific to Ozempic itself; it's a consequence of losing significant weight quickly, which depletes subcutaneous fat (including in the face) faster than the skin can adapt.
This is not a reason to avoid the medication, but it is a reason to:
- Aim for gradual, sustained weight loss rather than the fastest possible rate
- Maintain adequate protein intake (1.2–1.6g per kg of body weight) to preserve lean tissue
- Include resistance training to maintain muscle mass during weight loss
- Stay well-hydrated
Hair Loss on Ozempic
Hair thinning or shedding (telogen effluvium) is a common complaint among Ozempic users, typically appearing 3–6 months after starting the medication. It is not caused by the drug directly — it is caused by the physical stress of rapid weight loss and reduced calorie intake, which triggers a normal hair growth cycle disruption.
The good news: this type of hair loss is almost always temporary. Hair regrowth typically begins within 6–9 months as weight stabilises. To minimise it: eat adequate protein, avoid severe calorie restriction, and ensure you're not nutritionally deficient — particularly in iron, zinc, and biotin.
Serious but Less Common Side Effects
These are less frequent but require awareness and, in some cases, immediate medical attention:
Pancreatitis
Inflammation of the pancreas is a rare but serious potential complication of GLP-1 medications. Symptoms include severe abdominal pain that radiates to the back, nausea, and vomiting. Go to an emergency room immediately if you experience these symptoms. People with a personal or family history of pancreatitis should generally not use semaglutide.
Gallbladder Disease
Rapid weight loss of any kind increases the risk of gallstones, and Ozempic is no exception. Clinical trials showed a higher incidence of gallbladder-related issues (gallstones, cholecystitis) in semaglutide users. If you experience upper-right abdominal pain, especially after eating fatty foods, report it to your doctor.
Thyroid Tumours (Animal Studies Warning)
Semaglutide carries a black-box warning related to thyroid C-cell tumours observed in animal studies. This has not been confirmed in humans, but as a precaution, Ozempic is contraindicated in people with a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). Report any neck lump, difficulty swallowing, or persistent hoarseness to your doctor immediately.
Low Blood Sugar (Hypoglycaemia)
On its own, Ozempic rarely causes dangerous hypoglycaemia. However, when combined with other diabetes medications — particularly sulphonylureas or insulin — the risk of low blood sugar increases significantly. Monitor blood glucose closely if you are on combination therapy and discuss medication adjustments with your doctor.
Kidney Problems
Severe nausea, vomiting, and diarrhoea can lead to dehydration, which may worsen kidney function, particularly in people with pre-existing chronic kidney disease. Stay hydrated and report significant fluid loss to your doctor.
Side Effects That Might Surprise You: Mental Health
Emerging reports — and an ongoing global pharmacovigilance review by international medicines regulators — have flagged potential associations between GLP-1 medications and mental health changes, including depression, anxiety, and in rare cases, suicidal ideation. The evidence is not conclusive, and obesity itself is associated with higher rates of depression. However, if you notice significant mood changes, withdrawal from activities you enjoy, or any thoughts of self-harm while on Ozempic, contact your doctor immediately. Do not stop the medication abruptly without guidance.
South African Context: Affordability and Safe Use
With genuine Ozempic costing R2,500–R4,500 per month in South Africa, the financial pressure to find cheaper alternatives is real. However, counterfeit and compounded semaglutide products carry additional risks that go beyond the known side effect profile of the legitimate drug — including unknown impurities, incorrect dosing, and contamination. If cost is a barrier, discuss the registered generic alternatives now becoming available in SA with your prescribing doctor.
When to Stop Ozempic
Stop taking Ozempic and consult your doctor immediately if you experience:
- Severe, persistent abdominal pain (possible pancreatitis)
- Signs of allergic reaction: rash, swelling of face/lips/throat, difficulty breathing
- Vision changes (possible diabetic retinopathy progression)
- Rapid heart rate at rest
- Significant depression or suicidal thoughts
- A lump or swelling in the neck
Bottom line: Ozempic is a powerful, effective medication for weight loss and Type 2 diabetes management. Its side effects are real, common in the early months, and mostly manageable with the right strategies. The serious risks are rare but not negligible — which is why this is a prescription drug that requires ongoing medical supervision, not an over-the-counter solution. Use it under a doctor's care, understand the risks, and don't source it from unverified suppliers.