How to Guard (and Gain!) Muscle on GLP-1s

As weight-loss drug usage surges, so does a new priority: holding on to hard-earned strength.

- By Caitlin Carlson

Anbereen Hasan grew up swimming and dabbled in pilates as an adult, but she was looking to officially start a weight-loss journey after gaining pounds in her early 50s. (“It happened to every woman in my family as they got older,” she says.) She discussed the option of going on Mounjaro—a brand name for tirzepatide— with her doctor in November 2022.

Her physician was on board, as long as Hasan also agreed to begin resistance training—something she had done only briefly in the ’90s with five-pound weights—in order to preserve muscle mass. “My doctor was clear that I would have to do weight training,” Hasan says.

The 56-year-old found Tina Tang, CPT, a personal trainer, strength coach, and founder of Iron Strong Fitness, in April 2023 via Instagram. She liked that Tang was following Hasan’s endocrinologist and writing positive comments on the doctor’s posts. “We did a phone consultation and clicked right away.”

Hasan’s decision to invest in her muscle health was a smart one: While muscle loss is an issue for women to consider when losing weight by any means, the impact appears to be more drastic when a weight-loss drug is involved, according to a recent article in The Lancet Diabetes & Endocrinology. Specifically, studies suggest that muscle loss with GLP-1s can range from 25 to 39 percent of the total weight lost, while muscle loss with caloric restriction (resulting in less total weight lost) is 10 to 30 percent.

Plus, with newer and more powerful weight-loss drugs—like retatrutide— expected to arrive in 2026, patients could lose even more weight, and that might also mean losing more muscle. Semaglutide works by activating the GLP-1 receptor. Tirzepatide targets two receptors—GLP-1 and another one called GIP. Retatrutide goes even further by acting on three—GLP-1, GIP, and glucagon—making it a triple threat.