In adults with type 2 diabetes, retatrutide significantly improved total body fat mass reduction compared with placebo and dulaglutide. The proportion of lean mass loss to weight loss was similar to other obesity treatments.
In this phase 2 body composition substudy, participants receiving retatrutide demonstrated a reduction of up to 26.1% in the primary study endpoint of mean percent change in total body fat mass. For exploratory analyses, retatrutide also demonstrated body composition improvements at week 36 with mean reductions up to 10.9 kg in total fat mass and up to 0.6 kg in android visceral fat mass. There was also a loss of up to 6.5 kg in lean mass.
The findings from this substudy indicate that retatrutide in study participants improves body composition by a greater fat mass reduction versus lean mass loss in people with type 2 diabetes and supports further investigation of the efficacy on body composition and safety of retatrutide in phase 3 clinical trials.
These findings could provide reassurance that a greater proportion of lean mass is not lost with retatrutide despite the overall increased weight loss.
The proportion of lean mass loss to total weight loss with retatrutide was similar to other obesity treatments, providing reassurance that a greater proportion of lean muscle is not lost despite the overall increased weight loss. Retatrutide demonstrated dose-dependent effects on body composition.
In a phase 2 clinical trial, people with type 2 diabetes lost more fat on retatrutide than dulaglutide and placebo. Though the proportion of muscle mass lost was similar to that on other weight loss treatments. Clinical research shows that the amount of lean muscle mass lost on retatrutide is similar to that on other weight loss drugs.
Bodyweight reduction of up to 16·9% was observed after 36 weeks. Loss of lean mass is a potential concern of chronic GCG receptor activation due to decreased circulating amino acids, which could reduce protein synthesis in muscle. In preclinical models, retatrutide demonstrated greater reduction of fat mass than lean mass.
Retatrutide (tirzepatide) may preserve muscle mass better than semaglutide (Ozempic) due to its triple-hormone action, which could lead to more selective fat loss and better preservation of lean muscle mass.
In clinical trials, tirzepatide has shown approximately 15-20% total body weight reduction with about 70-75% of that coming from fat tissue, suggesting better muscle preservation compared to semaglutide.
Patients on retatrutide should implement a combination of resistance training (2-5 times weekly) and consume at least 1.2-1.5 g/kg/day of protein to effectively preserve muscle mass while on this medication.
When losing weight, some degree of muscle loss is to be expected. However, there’s ways you can prevent this: Eat enough protein. High protein intake helps preserve lean body and muscle mass during weight loss. Go for about 1.2–1.6 g/kg/day, distributed across 3–4 eating occasions. Hit the gym. Strength training helps to build muscle and improve strength. Aim for at least 2-3 sessions per week.
Yes, you can build muscle on retatrutide. Retatrutide doesn’t block or inhibit muscle building at all. But it won’t magically do the work for you. If you want to build muscle while on retatrutide, you’ll need to do it the old-fashioned way: regular strength training and eating a nutritious diet (including enough protein).
In one phase 2 trial, people with type 2 diabetes taking 8mg retatrutide lost 26.1% of total body fat mass over a year.
Studies show that Retatrutide helps reduce body fat while preserving lean muscle mass, leading to healthier long-term results.
Retatrutide’s ability to preferentially target fat mass while maintaining comparable lean mass preservation to other treatments makes it an attractive option for those seeking to improve body composition through pharmacological intervention, particularly when combined with appropriate exercise and nutritional strategies.
