Mounjaro, Wegovy, Ozempic and Tirzide: What Is the Difference?
Two active ingredients, five brands. A plain-English guide to how these weekly injections differ, and why each one needs a prescription.
Weekly injections for type 2 diabetes and weight management are among the most searched medicines in Kenya. The names can be confusing, so here is how the brands we stock differ. All of them are prescription-only medicines: they must be prescribed by a doctor and checked by a pharmacist before they are supplied.
Two active ingredients
- Tirzepatide acts on two hormone receptors, GIP and GLP-1. Brands: Mounjaro KwikPen (Eli Lilly) and Tirzide pre-filled syringe (Everest Pharmaceuticals).
- Semaglutide acts on the GLP-1 receptor. Brands: Wegovy and Ozempic (Novo Nordisk), and Noveltreat (Sun Pharma).
What each is used for
| Brand | Ingredient | UK-authorised use |
|---|---|---|
| Mounjaro | Tirzepatide | Type 2 diabetes (adults and children 10+), and weight management in adults with a BMI of 30 or more, or 27 to under 30 with a weight-related health problem |
| Wegovy | Semaglutide | Weight management in adults (same BMI thresholds) and in some adolescents aged 12+, and reducing cardiovascular risk in adults with established heart disease and overweight |
| Ozempic | Semaglutide | Type 2 diabetes in adults |
| Tirzide, Noveltreat | Tirzepatide / semaglutide | Your prescriber will explain the use of these brands |
Kenya's Pharmacy and Poisons Board has warned against using semaglutide medicines such as Ozempic for slimming without medical supervision. Use these medicines only as prescribed.
How the doses work
All of these medicines are injected under the skin once a week, and all start at a low dose that is increased step by step:
- Mounjaro: 2.5 mg for 4 weeks, then 5 mg, then 2.5 mg steps (at least 4 weeks each) up to a maximum of 15 mg. Each KwikPen holds 4 weekly doses. See our Mounjaro price guide.
- Wegovy: 0.25 mg in weeks 1 to 4, 0.5 mg in weeks 5 to 8, 1 mg in weeks 9 to 12, 1.7 mg in weeks 13 to 16, then 2.4 mg as the usual maintenance dose.
- Ozempic: starts at 0.25 mg for 4 weeks, then 0.5 mg; any higher dose is decided by your prescriber.
Missed a dose? For Mounjaro you can take it within 4 days; for Wegovy within 5 days. After that, skip it and continue on your usual day.
Common side effects
The most common side effects of both ingredients are nausea, diarrhoea, vomiting, constipation and stomach pain, mostly while the dose is being increased. Get urgent help for severe, persistent stomach pain or signs of a severe allergic reaction. None of these medicines should be used in pregnancy.
Which one is right for me?
That is a decision for your doctor, based on your health, your other medicines and why you need treatment. You can't switch between brands or ingredients without your prescriber's advice.
How to order at HealthSpot
Choose the medicine and strength on your prescription, tap Buy now on WhatsApp and send a photo of your prescription. Our pharmacist checks it first, and you only pay once it is approved. No prescription? Request a prescription review or explore our Weight Management service.
Sources: UK Summaries of Product Characteristics for Mounjaro KwikPen (Eli Lilly, Sep 2026) and Wegovy FlexTouch (Novo Nordisk, Sep 2026) on emc; Pharmacy and Poisons Board public notice on semaglutide (August 2025). General information only; it does not replace the patient leaflet or advice from your doctor or pharmacist.