Short answer: The most common weight-loss injection names are Mounjaro (tirzepatide), Zepbound (tirzepatide), Ozempic (semaglutide), Wegovy (semaglutide), Saxenda (liraglutide) and Trulicity (dulaglutide). There is also a tablet taken by mouth, Rybelsus.
Key takeaways
- Mounjaro and Zepbound contain dual-acting tirzepatide, which acts on both the GIP and GLP-1 receptors.
- Wegovy and Ozempic contain semaglutide, a pure GLP-1 receptor agonist.
- Mounjaro, Zepbound, Ozempic, Wegovy and Trulicity are given once a week; Saxenda is given once a day.
- Rybelsus is a once-daily oral tablet form of the active ingredient semaglutide.
The most common names of the medicines known as weight-loss injections are Mounjaro, Zepbound, Ozempic, Wegovy, Saxenda and Trulicity. All of them belong to the GLP-1 receptor agonist group; their active ingredients are tirzepatide, semaglutide, liraglutide and dulaglutide. All of them are prescription-only.
This page is for general information only, is not medical advice and does not promote any medicine. Which medicine is suitable is a decision only a doctor can make.
Comparison table
| Brand | Active ingredient | Frequency | Mechanism of action | Official information |
|---|---|---|---|---|
| Mounjaro | Tirzepatide | Once a week | GIP + GLP-1 | EMA |
| Zepbound | Tirzepatide | Once a week | GIP + GLP-1 | US-only name |
| Ozempic | Semaglutide | Once a week | GLP-1 | EMA |
| Wegovy | Semaglutide | Once a week | GLP-1 | EMA |
| Rybelsus | Semaglutide | Once a day (by mouth) | GLP-1 | Tablet form |
| Saxenda | Liraglutide | Once a day | GLP-1 | EMA |
| Trulicity | Dulaglutide | Once a week | GLP-1 | EMA |
The official information column refers to the European Medicines Agency (EMA) assessment pages. For the licensing status, approved indications and current product information in the UK, use the MHRA as your reference.
How they differ
What is the difference between Mounjaro and Ozempic?
The key difference is the active ingredient. Mounjaro contains tirzepatide and acts on two separate hormone receptors at once: GIP and GLP-1. Ozempic contains semaglutide and acts only on the GLP-1 receptor. Both are given once a week. In clinical trials, weight-loss results for dual-acting tirzepatide were higher, but whether a medicine suits you is a separate medical assessment.
Are Ozempic and Wegovy the same medicine?
They have the same active ingredient: semaglutide. The difference lies in the indication and the dosing schedule. Ozempic is licensed primarily for type 2 diabetes, while Wegovy is licensed for weight management and follows different dose steps. The same applies to Mounjaro and Zepbound: both are tirzepatide, and Zepbound is the name used in the US market for the weight-management indication.
Are they all injections?
No. Rybelsus is a tablet form of semaglutide taken by mouth, once a day. The others are injections given under the skin.
Weekly or daily?
Mounjaro, Zepbound, Ozempic, Wegovy and Trulicity are given once a week. Saxenda and Rybelsus are used once a day. This distinction matters in practice: with a weekly medicine, remembering the dose day is the hard part; with a daily medicine, it is not missing the routine.
Whichever medicine you use, the tracking is the same
Whatever the name or active ingredient, the things your GP or prescriber will ask about during treatment are similar: which day you injected, which site you used, how your weight changed, which day you had side effects. These are hard to remember accurately.
Haftra is a free iPhone app that keeps this record in one place. It supports all of the medicines above and works with both weekly and daily schedules. It can be used without an account, and then your records stay on your phone. It does not suggest doses or make diagnoses.
iPhone, iPad and Apple Watch. Free.
Frequently asked questions
What are the names of weight-loss injections?
The best-known products are Mounjaro, Zepbound, Ozempic, Wegovy, Saxenda and Trulicity. Their active ingredients are, in order, tirzepatide, tirzepatide, semaglutide, semaglutide, liraglutide and dulaglutide. All of them are prescription-only.
What is the difference between Mounjaro and Ozempic?
Mounjaro's active ingredient is tirzepatide, and Ozempic's is semaglutide. Tirzepatide acts on both the GIP and GLP-1 receptors, semaglutide only on GLP-1. Both are given once a week. In clinical trials, tirzepatide showed higher rates of weight loss.
Are Ozempic and Wegovy the same medicine?
They have the same active ingredient: semaglutide. However, they are separate brands with different dose steps: Ozempic is licensed for type 2 diabetes and Wegovy for weight management.
Which weight-loss injection is the most effective?
In the SURMOUNT-1 clinical trial, tirzepatide (Mounjaro/Zepbound) produced the highest average weight loss (20.9%); however, the most suitable medicine for you is decided by a doctor after an assessment.
Related pages
Sources
- EMA: Mounjaro (tirzepatide)
- EMA: Ozempic (semaglutide)
- EMA: Wegovy (semaglutide)
- EMA: Saxenda (liraglutide)
- EMA: Trulicity (dulaglutide)
- MHRA (Medicines and Healthcare products Regulatory Agency)
Last reviewed: 2 August 2026
