Editorial warns about muscle loss on GLP-1 drugs in older adults

An editorial published in Annals of Internal Medicine on September 18, 2025, warns that GLP-1 receptor agonists such as semaglutide (Ozempic, Wegovy) may worsen age-related muscle loss in adults over 65, pushing some patients toward frailty ^[1].

The editorial, titled "Skeletal Muscle Mass Loss and Glucagon-Like Peptide-1 Receptor Agonists: Are Older Patients at Risk?" and written by Anjali P. Kakkar and colleagues, points out that normal aging already reduces skeletal muscle mass by 12% to 16%, leaving older adults with little buffer before crossing into frailty ^[1]. Up to half of adults over age 80 already have sarcopenia, the medical term for age-related muscle loss, which raises the risk of falls, fractures, and disability ^[1].

Use of GLP-1 drugs rose sharply between 2018 and 2022, from a few thousand users to tens of thousands nationwide, including older and high-risk patients ^[1]. These drugs can produce weight loss exceeding 20%, but not all of that loss is fat ^[1]. A 2024 review in Diabetes, Obesity & Metabolism found that lean mass, which includes muscle, can account for 15% to 60% of total weight lost on GLP-1 drugs, depending on the patient and the specific drug ^[1]. Some of that muscle loss may be offset by improvements in muscle quality, such as less fat stored within muscle tissue, but the editorial says older patients may not get the same benefit, especially if the loss affects their ability to move or their strength ^[1].

The editorial calls for closer monitoring. It says clinicians should check for skeletal muscle mass loss if a patient does not show expected gains in physical function during treatment ^[1]. Detailed imaging tools like MRI and CT scans can measure muscle loss accurately but are expensive and not always practical for routine use ^[1]. More accessible options, such as DEXA scans and bioimpedance analysis, exist but vary in reliability ^[1].

Why it matters for patients

For older adults considering or already taking GLP-1 drugs, the editorial's warning centers on a basic tradeoff: these medications can produce large weight loss, but some of that loss comes from muscle rather than fat ^[1]. Because muscle mass naturally declines with age, this compounding effect could matter more for people already close to frailty thresholds, even if they do not notice symptoms right away ^[1].

The editorial's authors recommend that clinicians assess baseline muscle mass, physical function, and nutrition before prescribing these drugs to older adults, and pair treatment with resistance training and a high-protein diet ^[1]. No drug is currently approved specifically to prevent muscle loss during GLP-1 treatment, though the editorial notes that companies including Eli Lilly and Scholar Rock are developing therapies, such as myostatin inhibitors and enobosarm, aimed at preserving muscle while patients lose fat ^[1].

What this means in practice for an individual patient is not spelled out in the sources beyond the general call for more personalized care and monitoring ^[1]. The sources do not specify exact screening schedules, cutoff thresholds for concern, or how these recommendations might differ for tirzepatide (Mounjaro, Zepbound) or other GLP-1 drugs; that level of detail is not yet known from the available information.

What happens next

The editorial calls for future study into how to help patients gain the metabolic benefits of GLP-1 drugs without losing strength or mobility ^[1]. It does not give a timeline for when such research might produce new clinical guidance, and no regulatory action is mentioned in the sources.