Should you really worry about muscle loss?

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

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

One potential downside related to GLP-1 medicines is that weight reduction not solely consists of fats loss, however muscle loss as nicely, 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 printed within the International Journal of Obesity has discovered that, over time, the vast majority of weight reduction from GLP-1 remedy was from fats loss, and never muscle loss.

For this examine, researchers analyzed findings and information from 36 previously-conducted research. The chosen research examined the impression 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 medicines for 3 months, individuals skilled a lack of about 9% of their beginning weight.

Nonetheless, 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 Heart at Orange Coast Medical Heart in Fountain Valley, CA, about this examine.

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

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

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

A examine printed in August 2025 discovered that lean muscle mass loss by way of 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, slightly than from skeletal muscle mass.

And analysis offered on the European Congress on Weight problems (ECO 2025) reported that adults taking GLP-1 medicine had been capable of retain muscle while losing weight by power coaching and consuming sufficient protein.

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

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

“It gives a strong meta-analysis that confirms what many people have been observing in scientific 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 vital issue for long-term well being.”

Ewing mentioned it’s essential for researchers to proceed analyzing how GLP-1 medicines impression an individual’s physique composition for a number of causes. He detailed:

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

“Fast weight reduction can typically result in sarcopenia, a situation characterised by the lack of muscle mass and performance,” Ewing continued. “Continued analysis will help establish methods to mitigate this danger, particularly in weak populations.“

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