Explore how semaglutide, tirzepatide and retatrutide work, their results and risks.
Separate pathways in this area: Retatrutide · Semaglutide · Tirzepatide.
A research question connects these topics. The quality of evidence and each substance's status may differ completely.
Learn the terms, how to read research and the key safety information.
Weight loss / Health
Retatrutide is an investigational substance acting on receptors for three hormones involved in appetite and metabolism. Large trials in people with obesity, including those with type 2 diabetes, were published in 2026. The findings are promising, but publication does not mean a new medicine has been approved.
Weight loss / Health
Semaglutide is the active ingredient in Wegovy, Ozempic and Rybelsus. It is a peptide used in legally authorised prescription medicines that help treat type 2 diabetes or manage body weight, depending on the product.
Weight loss / Health
Tirzepatide is an active ingredient in prescription medicines. In the EU, Mounjaro is used for type 2 diabetes and excess-weight treatment in defined patients. In the USA, Zepbound is used for purposes including obesity treatment. Benefits and limitations come from studies of specific medicines.
Mounjaro, which contains the active ingredient tirzepatide, is injected under the skin — including into the abdomen when there is a noticeable layer of fat. We explain what is known about injection sites and why the medicine must not be injected into a muscle.
The aim of treatment is not to stop eating. The return of appetite is not a reason to take extra injections. We explain what is known about how Semaglutide works and why more medicine does not mean better treatment.
A new analysis from September 2026 concerns body composition and physical function during obesity treatment. Its small size calls for careful interpretation.
People taking retatrutide lost weight in studies. Let us look at how much changed and what else matters.
Semaglutide is associated with injection pens. Newer research and European documents show what is also known about tablets. Important safety updates are appearing alongside these developments.
More studies are looking at what happens after the initial weight loss. A 2026 publication examines different ways of continuing treatment with tirzepatide.