GeroScienceNov 4, 2026, 12:49 GMT

Semaglutide did not shrink lab-grown human muscle cells

Muscle cells from six older adults with obesity showed no thinning after 24 hours of exposure to semaglutide or a gut hormone, compared with controls.

Paper by Caitlin M. Ditchfield, Michael Macleod, Joshua M. J. Price, Edward Thomas Davis, Simon Wyn Jones

Figure 1 from GeroScience — Figure 1. Ditchfield et al., CC BY

Our read

Interventions

Studied:: Experiments in 6 primary human skeletal muscle myotubes, 24 h, against DMSO vehicle-treated myotubes
What changed:: Lab-grown muscle cell thickness did not differ with semaglutide versus vehicle control after 24 h
The catch:: Only 6 donors contributed to most assays, limiting detection of modest thinning
In the record:: The 3rd paper on gip with results in people; 12 on record in all.
Why it’s aging research:: An intervention with evidence on lifespan or healthspan.

Editor of record: Boris Djordjevic · AgingResearch.News

Paper

Human muscle cells from six older adults with obesity undergoing hip or knee replacement were tested in a laboratory experiment. Cells received semaglutide at 10 nanomolar or the gut hormone glucose-dependent insulinotropic polypeptide at 5.02 micromolar. After 24 hours, neither exposure thinned the fused muscle cells compared with matching controls. Neither impaired muscle-cell formation during eight days of exposure.

No significant changes appeared in activity of genes linked to muscle wasting or in proteins the cells released. Semaglutide reduced sugar-based and total production of ATP, the molecule cells use for energy, in cells from four donors. Neither compound altered measures of mitochondria, the cells’ energy-producing structures.

Why it matters

Older adults at risk of age-related muscle loss face particular concerns about losing lean mass during weight-loss therapy. The authors said their findings were consistent with an indirect mechanism underlying that loss.

Caveats

Lab-grown cells exposed for up to eight days do not capture long-term muscle changes in people losing weight. Neither compound produced convincing evidence of receptor signaling in the test used, limiting conclusions about receptor activation.

Where the evidence stands

Semaglutide

C, W, M, H: cells, worms or flies, mice, humans. Dark: independent labs found the same change there. Light: one lab or one study. Outline: nothing yet.

Labs are independent when their papers share no last author and no institution.

Against: findings that point the other way from most findings on the same outcome.

No results posted: trials that ended over a year ago with no results on ClinicalTrials.gov and no paper reporting them.

Company ties: findings with an author at a company, or from a paper whose competing-interests statement declares ties to one.

396 independent labs in 60 countries
94 findings against
407 trials, 97 with no results posted

Funders: Novo Nordisk and others
366 of 1,428 findings with company ties
214 of 407 trials sponsored by its developers

Gip

2 independent labs in 1 country

Funders: Birmingham Biomedical Research Centre and 2 more

From the paper

Limitation

First, the myotubes used were derived from older adults undergoing elective joint replacement surgery for end-stage osteoarthritis, a condition associated with chronic systemic inflammation, altered muscle metabolism, and age-related skeletal muscle changes.

Discussion

Quoted word for word from the full text on link.springer.com.