Almost always, it's the weight loss. Hair shedding reported by people on Ozempic, Wegovy, Zepbound or compounded GLP-1s is generally telogen effluvium - a well-understood response in which a major physiological stressor (and losing weight quickly is one) pushes an unusually large share of hair follicles into their resting-and-shedding phase at once.
The same shedding happens after bariatric surgery, crash diets, childbirth and serious illness - none of which involve GLP-1 medication. In clinical trials, hair loss was reported by a small minority of participants, more often than on placebo - consistent with the drugs driving faster weight loss rather than attacking hair directly.
