Evidence-graded answer
Does Ozempic cause hair loss?
Not directly. Hair shedding (telogen effluvium) is reported by some patients ~3 months into rapid weight loss — typical of any rapid-weight-loss state, not unique to GLP-1.
Telogen effluvium is hair follicles shifting prematurely from growth to shedding phase, usually triggered by physiologic stress including rapid weight loss, surgery, or major illness.
STEP-1 trial (semaglutide 2.4 mg) reported alopecia in 3% of treated patients vs 1% placebo — a small absolute increase consistent with rapid-weight-loss hair shedding rather than a drug-specific effect.
Most patients see hair regrowth 6-12 months after weight stabilizes. Adequate protein intake (1.2-1.6 g/kg ideal body weight) and iron labs are reasonable next steps.
Source: STEP-1 NEJM 2021, NEJM (opens in a new tab)