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semaglutide (Wegovy) and hair shedding (telogen effluvium): incidence, timing, mechanism, evidence-graded management, and when to escalate.
| Drug | Reported incidence | vs placebo |
|---|---|---|
| Wegovy (this page) | 3% | ~1% |
| Ozempic | 3% | ~1% |
| Mounjaro | 3% | ~1% |
| Zepbound | 3% | ~1% |
| Saxenda | 3% | ~1% |
Cells graded on a calm severity scale (lighter = lower). Figures are from each drug's pivotal trial / FDA label and are not head-to-head; doses and populations differ.
Typical onset, peak, and resolution from pivotal-trial timing. Drag the slider to read what most patients experience that week. Individual experience varies — this is a guide, not medical advice.
Typically 2–4 months after the period of fastest weight loss (delayed, by design of the hair cycle). Self-limited: usually resolves within 3–6 months once weight stabilizes and nutrition is adequate; hair regrows.
Rapid weight loss and the metabolic/nutritional shift push a larger share of follicles into the resting (telogen) phase at once; Wegovy causes this indirectly through the pace of loss, not by a direct toxic effect on follicles.
Ensure adequate protein and total calories; correct iron, ferritin, vitamin D, and zinc if low.
Nutritional sufficiency supports the hair cycle; deficiencies worsen telogen effluvium.
Lose weight more gradually — a smaller deficit reduces the shedding trigger.
Severity tracks the speed/magnitude of weight loss.
Be patient: shedding is the visible tail of a stress that already passed; regrowth is the norm.
Telogen effluvium is self-limited and reverses in nearly all cases.
Discuss topical minoxidil with a clinician only if shedding is prolonged or distressing.
May speed cosmetic recovery; elective, not necessary for resolution.
Each step is graded A (strongest evidence) to D (weakest), on the same scale used across LoseLab. Grades reflect strength of supporting evidence, not how essential a step is for you.
Telogen effluvium frightens people because it shows up after the hard part is over. It is self-limited and reverses in almost everyone once weight and nutrition stabilize.
| Symptom | Incidence | Onset |
|---|---|---|
| Nausea | 44% | Usually 24–48 h after the first dose and after each dose step-up. |
| Vomiting | 24% | Clusters in the first week of each new dose step, often after overeating past the new appetite ceiling. |
| Diarrhea | 30% | Most common in the first 4 weeks of each titration step; often alternates with constipation. |
| Constipation | 24% | Builds gradually over the first 4–8 weeks. |
| Fatigue | 11% | Most common in the first month of titration and during periods of very low intake. |
| Headache | 14% | Variable; clusters around titration and dehydration episodes (after nausea or diarrhea). |
| Sulfur burps | Less common | Can appear within days of a dose, often after high-protein, high-sulfur, or fatty meals. |
| Injection-site reaction | 4% | Within hours to a day or two of an injection. |
| Facial fat loss ("Ozempic face") | Common | Becomes visible after roughly 8–12% total body-weight loss, typically months 3–6. |
| Muscle / lean-mass loss | Common | Begins with weight loss itself (weeks–months); proportion of lean loss is highest when loss is fast and protein/training are low. |
| Hair loss (telogen effluvium) | 3% | Typically 2–4 months after the period of fastest weight loss (delayed, by design of the hair cycle). |
Editorial summary, not medical advice. Incidence figures from FDA prescribing information and pivotal trial publications; qualitative bands are used where no trial reports a clean percentage. Individual experience varies. Coordinate side effect management with your prescriber.