Is retatrutide more effective than Ozempic?

Retatrutide acts on three hormone receptors simultaneously, whereas semaglutide targets only one. In network meta-analyses that compare multiple studies indirectly, retatrutide 12 mg comes out on top among all agents examined: an average weight loss of 22% after 48 weeks compared with placebo. Semaglutide 2.4 mg (sold at a higher dose for obesity as Wegovy) achieves around 14% weight loss in the same comparison. That looks like a substantial difference, but it is important to know that this is an indirect comparison, not a direct head-to-head trial.

There is in fact no study in which people were randomly assigned to either a retatrutide group or a semaglutide group. All claims about 'who wins' come from statistical network comparisons. Such analyses can be distorted by differences in study populations, study duration, and the way outcomes are measured. The certainty about the precise difference is therefore limited.

On top of that, retatrutide is not yet on the market at all. The large phase 3 studies are still ongoing and must confirm long-term safety and efficacy. The available safety data come mainly from a single phase 2 study. The most commonly reported side effects are gastrointestinal complaints such as nausea, vomiting, and diarrhoea. These occurred in 47 to 84% of participants, were predominantly mild, and decreased when the starting dose was lower. Heart rate also rose temporarily, but whether that matters in the long term is still unknown.

If you want to do something about your weight now and qualify for medication, retatrutide is not an option. Semaglutide and tirzepatide are approved and available. Based on the indirect comparisons, tirzepatide (which also acts on two receptors) already appears to be more effective than semaglutide, and retatrutide appears to go beyond that still. But until the phase 3 data are in, that remains a promise, not a certainty.