Revision History

A new study in Cell Reports Medicine argues that GLP-1 weight-loss drugs do not cause disproportionate muscle loss compared to other weight-loss methods, challenging a narrative that has dogged the medications since the STEP 1 trial. But questions about older adults, long-term functional outcomes, and industry funding mean the debate is far from settled — even as the $58 billion GLP-1 market expands and Medicare prepares to cover these drugs starting July 2026.