From the Research
Tirzepatide may cause some muscle loss as a side effect, but this can be minimized with proper strategies, such as incorporating regular resistance training and ensuring adequate protein intake, as evidenced by the most recent study in 2025 1. To prevent significant muscle loss while taking tirzepatide (Mounjaro, Zepbound),
- incorporate regular resistance training at least 2-3 times per week
- ensure adequate protein intake of 1.2-2.0 grams per kilogram of body weight daily. Tirzepatide works by mimicking GLP-1 and GIP hormones to regulate blood sugar and reduce appetite, leading to weight loss that can include both fat and some muscle tissue. The muscle loss occurs primarily because of the caloric deficit created and reduced food intake, not directly from the medication itself. To maintain muscle mass,
- spread protein consumption throughout the day
- stay hydrated
- consider working with a healthcare provider to monitor body composition changes. Adding moderate cardio exercise can help maintain cardiovascular health without excessive muscle catabolism. These strategies are important because preserving muscle mass during weight loss helps maintain metabolic rate, physical function, and long-term weight management success, as supported by the findings of the SURPASS-3 MRI substudy 1. Additionally, a systematic review and meta-analysis published in 2025 found that tirzepatide has a reassuring renal safety profile, which is essential for overall health and well-being 2. It is also worth noting that tirzepatide has been associated with significant reductions in body weight and improvements in glycemic control, as demonstrated in the SURPASS trials 3, 4, 5. Overall, while tirzepatide may cause some muscle loss, the benefits of the medication, including improved glycemic control and weight loss, can be maximized with proper strategies to minimize muscle loss.