Should you really worry about muscle loss?

• The usage of GLP-1 drugs for weight reduction continues to rise.
• One downside related to GLP-1 drugs is that weight reduction not solely contains fats loss, however muscle loss as effectively.
• A brand new examine discovered that over time, the vast majority of weight reduction from GLP-1 treatment was from fats loss, and never muscle loss.

And with the current approval by the Meals and Drug Administration (FDA) of the Wegovy pill for weight reduction, researchers count on GLP-1 treatment utilization to proceed to develop.

One potential downside related to GLP-1 drugs is that weight reduction not solely contains fats loss, however muscle loss as effectively, with some research discovering that about 30% of the weight loss from GLP-1s could also be contributed to lack of lean mass, or muscle mass.

Now, a brand new examine revealed within the International Journal of Obesity has discovered that, over time, the vast majority of weight reduction from GLP-1 treatment was from fats loss, and never muscle loss.

For this examine, researchers analyzed findings and knowledge from 36 previously-conducted research. The chosen research examined the affect of GLP-1 and dual GLP-1/GIP agonists on weight reduction and physique composition modifications in adults who had been obese or overweight, and who could or could not have type 2 diabetes.

Upon evaluation, scientists discovered that after utilizing the drugs for 3 months, individuals skilled a lack of about 9% of their beginning weight.

Nevertheless, after 3 months, researchers found solely a modest loss in lean body mass.

Then after 12 months of GLP-1 utilization, researchers reported that individuals skilled main reductions in visceral adipose tissue and fats physique mass.

And whereas there was obvious lean physique mass loss, scientists discovered it was comparatively modest when in comparison with the quantity of physique mass loss.

Medical Information At present spoke with Mir Ali, MD, a bariatric surgeon and medical director of MemorialCare Surgical Weight Loss Middle at Orange Coast Medical Middle in Fountain Valley, CA, about this examine.

Ali commented that this examine’s findings align together with his medical experiences.

“Sufferers primarily lose fats when utilizing these drugs,” he defined. ”Whereas some muscle loss could happen, the vast majority of the load loss is fats loss.”

This isn’t the primary examine to point out that weight reduction from the usage of GLP-1 drugs could also be decrease than we predict.

A examine revealed in August 2025 discovered that lean muscle mass loss through a mouse mannequin was lower than earlier research had reported, and likewise discovered {that a} good portion of the lean muscle mass decrease came from other tissues, such because the liver, fairly than from skeletal muscle tissues.

And analysis introduced on the European Congress on Weight problems (ECO 2025) reported that adults taking GLP-1 medication had been in a position to retain muscle while losing weight by energy coaching and consuming sufficient protein.

MNT additionally had the chance to talk with Douglas R. Ewing, MD, FACS, DABOM, medical director of the Middle for Weight Loss and Metabolic Well being at Hackensack College Medical Middle in New Jersey, about this examine.

Ewing commented that as a physician who treats sufferers who could also be taking a GLP-1 treatment, his first response to the examine’s outcomes was considered one of measured approval.

“It offers a sturdy meta-analysis that confirms what many people have been observing in medical apply: GLP-1 receptor agonists are efficient for weight reduction and, importantly, this weight reduction seems to be of ‘prime quality,” he defined. “This implies sufferers are shedding extra fats mass than lean physique mass, which is a important issue for long-term well being.”

Ewing stated it’s essential for researchers to proceed inspecting how GLP-1 drugs affect an individual’s physique composition for a number of causes. He detailed:

“Muscle is extra metabolically lively than fats. A big lack of muscle mass can decrease an individual’s metabolic fee, making it tougher to take care of weight reduction in the long term. Preserving muscle mass is crucial for sustaining energy, mobility, and general bodily operate. That is significantly necessary for older adults, who’re already at the next danger of falls and frailty.”

“Speedy weight reduction can generally result in sarcopenia, a situation characterised by the lack of muscle mass and performance,” Ewing continued. “Continued analysis may also help determine methods to mitigate this danger, particularly in susceptible populations.“

“If an individual loses a big quantity of muscle whereas on a GLP-1 after which stops taking the treatment, they could be extra vulnerable to regaining weight, and this regained weight could also be primarily fats,” famous Ewing.