Hair loss on GLP-1 medications: why it happens and how long it lasts

How common is hair loss on semaglutide and tirzepatide?

Hair loss rates in weight-loss trials ranged up to about 7%. In Wegovy trials of 2,116 people on semaglutide 2.4 mg, 3% reported hair loss versus 1% on placebo, and across tirzepatide trials the rate was 5.4% versus 0.9%. In Zepbound trials it was far more common in women, at 7.1%, than in men, at 0.5% ^[1].

• Tirzepatide, SURMOUNT-1 (5, 10 and 15 mg): 4.9% to 5.7% versus 0.9% on placebo ^[1].
• Tirzepatide after an intensive lifestyle program, SURMOUNT-3: 7% versus 1.4% on placebo ^[1].
• Oral semaglutide 50 mg a day, OASIS 1: 7% versus 3% on placebo ^[1].
• A meta-analysis of randomized trials cited by the review: 6.0 versus 0.8 cases per 1,000 patient-years, about three times the risk ^[1].

Not every study agrees. Several record-based studies found no increased risk, and many trials did not systematically look for hair loss, so reported rates may be too high or too low ^[1].

Why does hair fall out on a GLP-1?

Most reported cases look like telogen effluvium, a temporary shedding in which stress on the body pushes many hairs into their resting phase at once. The 2026 review points to rapid weight loss, calorie restriction and possible short-term shortfalls in nutrients such as protein, iron and zinc as likely triggers, a pattern also seen after bariatric surgery ^[1].

Hair loss tracked with the amount of weight lost. In Wegovy trials, 5.3% of people who lost more than 20% of their body weight reported it, compared with 2.5% of those who lost less. Tirzepatide, which produces the largest weight loss of these drugs, is the one most often linked to telogen effluvium ^[1].

Telogen effluvium can also unmask pattern hair loss that was already developing, which may explain some reports of androgenetic alopecia in people taking these medications ^[1].

For protein targets while taking these drugs, see our guide to protein on a GLP-1 medication.

When does GLP-1 hair loss start, and how long does it last?

Shedding tied to weight loss would be expected about 1.5 to 3 months after starting treatment or raising the dose. The 2026 review describes it as typically self-limited and reversible, with improvement generally within 3 to 6 months once weight stabilizes, and it found no strong evidence of permanent damage to hair follicles ^[1].

Timing is poorly studied. One large record-based study found an average of 1.75 years between starting a GLP-1 and a new hair loss diagnosis, which may reflect a different process from shedding after rapid weight loss ^[1].

Shedding that continues beyond 6 months is considered chronic and may point to an ongoing trigger, such as continued calorie or nutrient shortfalls ^[1].

Can you lower the chance of hair shedding on a GLP-1?

The chance of shedding may be lower if weight comes off less abruptly and intake stays adequate. The 2026 review suggests avoiding dramatic weight loss and severe calorie restriction, getting enough protein, iron, zinc, vitamin D, vitamin B12 and vitamin A, and says slower dose increases may be considered to limit rapid weight change. Dose decisions belong to your prescriber ^[1].

Nutrition changes and vitamin supplements have been moderately successful in some groups with telogen effluvium, but the review notes that strategies for GLP-1 users still need to be studied ^[1].

For the nutrients involved, see our guide to nutrient deficiencies on GLP-1 medications and our comparison of iron forms.

Does biotin help with hair loss on a GLP-1?

Biotin has little evidence behind it for hair loss. The NIH says biotin supplements promoted for hair, skin and nails are supported, at best, by a few case reports and small studies ^[2], and biotin deficiency is very rare in the United States ^[3]. High-dose biotin can also cause false results on some lab tests, including thyroid tests and troponin, a heart attack test ^[2].

Even a single 10 mg dose of biotin has interfered with thyroid function tests taken within 24 hours, and the FDA reported a death after a falsely low troponin result in a person taking high doses. If you take biotin, tell your clinician before any blood test ^[2].

The 2026 review of GLP-1 hair loss does not list biotin among its suggested strategies ^[1].

When should you see a doctor about hair loss on a GLP-1?

See a clinician, ideally a dermatologist, if shedding lasts beyond 6 to 9 months, if thinning follows a pattern or hairs are getting finer, or if your scalp itches or looks inflamed. Scalp itching or inflammation can signal scarring hair loss. For persistent shedding after rapid weight loss, the review says blood tests such as a complete blood count, ferritin, thyroid-stimulating hormone and vitamin D may be considered ^[1].

If shedding is severe or distressing, weight loss is very rapid, or a nutrient deficiency is confirmed, the review says a dose adjustment or temporary pause may be considered case by case. That is a decision for your prescriber, not something to do on your own ^[1].

What this evidence can't tell you

• Most evidence comes from trial side-effect reports, health-record studies and adverse-event databases, which show associations, not cause ^[1].
• Hair loss was often not a planned trial outcome, and its type and timing were rarely confirmed by a dermatologist ^[1].
• Women may notice and report hair loss more often, so part of the difference between women and men could come from reporting ^[1].
• One of the review's authors reports research grants from companies including Eli Lilly and Pfizer ^[1].