Hair loss is a listed side effect of both Wegovy and Zepbound, and both labels say it was linked to weight reduction. In the main trials it was reported by 3% of people on Wegovy 2.4 mg, about 6% on the newer Wegovy 7.2 mg dose, and 4% to 5% on Zepbound, compared with about 1% on placebo. Almost all of the cases were in women. This guide goes through the exact label numbers, what is known about shedding after fast weight loss, and when hair loss is worth a visit to a doctor.
The trial figures come from the FDA prescribing information for Wegovy (semaglutide) and Zepbound (tirzepatide). The biology comes from peer-reviewed papers, linked as we go.
The labels list side effects that showed up in at least 2% of people on the drug and more often than on placebo, the dummy injection. Hair loss made both lists. Rounded to whole numbers, as the label tables print them:
| Trial group (label) | Drug | Placebo |
|---|---|---|
| Wegovy 2.4 mg, adults, up to 68 weeks | 3% | 1% |
| Wegovy 7.2 mg, adults, 72 weeks | 6% | 1% |
| Wegovy 2.4 mg in the 7.2 mg trials | 3% | 1% |
| Wegovy 2.4 mg, ages 12 and up, 68 weeks | 4% | 0% |
| Zepbound 5 mg, adults, up to 72 weeks | 5% | 1% |
| Zepbound 10 mg | 4% | 1% |
| Zepbound 15 mg | 5% | 1% |
Sources: Wegovy label, section 6.1, Tables 3, 4 and 5; Zepbound label, section 6.1, Table 1. Trials are not head-to-head, and the labels warn that rates from different drugs' trials cannot be directly compared.
In three placebo-controlled trials of Wegovy 2.4 mg in adults, lasting up to 68 weeks, hair loss was reported by 3% of people on the drug and 1% on placebo (Table 3). The label then gives a more exact pooled figure for Studies 2, 3 and 4: 3.3% on Wegovy 2.4 mg (4% of women, 0.9% of men) versus 1% on placebo (2% of women, 0 men).
The current label also covers the higher 7.2 mg weekly dose, tested in two 72-week trials (Studies 8 and 9). There, hair loss was reported in:
In the 7.2 mg group, 1 hair loss event led someone to stop the drug for good, 1 led to a pause, and 5 led to a lower dose. None of those happened in the 2.4 mg or placebo groups. In a 68-week trial in teenagers aged 12 and older, hair loss was reported by 4% on Wegovy 2.4 mg and by no one on placebo. The label says hair loss in Wegovy-treated patients was "associated with weight reduction" (Wegovy label, 6.1). For Wegovy tablets, the label says the types and rates of common side effects were similar to the 2.4 mg injection.
Zepbound was tested in a pool of two placebo-controlled trials (Studies 1 and 2) of up to 72 weeks. Hair loss was reported by 5% on 5 mg, 4% on 10 mg and 5% on 15 mg, against 1% on placebo (Table 1). So the rate did not climb with dose in these trials.
The sex split is wide. Hair loss was reported by 7.1% of women versus 0.5% of men on Zepbound, and by 1.3% of women versus 0% of men on placebo. No one on Zepbound stopped the drug because of hair loss; one person on placebo did. Like Wegovy's, the Zepbound label says hair loss "adverse reactions" were associated with weight reduction (Zepbound label, 6.1).
Here are the sex-specific numbers side by side:
| Trial pool (label) | Women on drug | Men on drug | Women on placebo | Men on placebo |
|---|---|---|---|---|
| Wegovy 2.4 mg (Studies 2, 3, 4) | 4% | 0.9% | 2% | 0% |
| Wegovy 7.2 mg (Studies 8, 9) | 8.4% | 0.2% | 1.5% | 0% |
| Wegovy 2.4 mg (Studies 8, 9) | 5.4% | 0% | 1.5% | 0% |
| Zepbound, all doses (Studies 1, 2) | 7.1% | 0.5% | 1.3% | 0% |
Ozempic (semaglutide) and Mounjaro (tirzepatide) are approved for type 2 diabetes. Their labels do not list hair loss among the common trial side effects, but both list alopecia (the medical word for hair loss) under postmarketing experience: reports sent in after approval (Ozempic label, 6.2; Mounjaro label, 6.2). The labels note that these reports are voluntary and come from a population of unknown size, so a rate cannot be worked out and cause cannot always be proven.
The labels report the gap but do not explain it. One thing to keep in mind is who was in the trials. Wegovy's 2.4 mg trials were 71% female, and the 7.2 mg arm was 70% female. Zepbound's trials were 37% male, so about 63% female (our arithmetic). Even so, the rates are given within each sex, so the gap is not just a head count. It is a real difference in the trial data, without a known cause.
When the labels say hair loss was "associated with weight reduction," the most common pattern people have in mind is telogen effluvium. That is a long name for diffuse shedding, meaning hair thins all over rather than in patches, and it does not scar the scalp.
A 2020 review explains how it works (Asghar 2020). Hair grows in cycles. About 90% of scalp hairs are in the growing phase, which lasts about two to five years. About 10% are in the resting phase, which lasts around three to five months, after which the hair falls out. A shock to the body can push many growing hairs into the resting phase at once. They then fall out together, generally two to three months after the trigger.
The review lists triggers that include severe protein deficiency, starvation and calorie restriction, along with surgery, high fever, illness, some medicines and thyroid problems. Shedding that lasts less than six months is called acute. The review says acute telogen effluvium usually settles on its own once the trigger is found and removed, and that regrowing short hairs along the front of the scalp are a sign of recovery.
The review is not about GLP-1 drugs. But it helps explain the timing many people notice: shedding that starts a few months into treatment, often after the fastest stretch of weight loss, rather than in the first weeks.
Two 2026 meta-analyses, which pool data from many studies, looked at GLP-1 drugs and hair loss directly:
The trial-based rate of about 4% is close to what the labels show. The records-based studies measure diagnoses, not cause, so they cannot prove the drug itself is to blame rather than the weight loss.
Diffuse shedding a few months into treatment fits the pattern above, but other causes look similar, and some need treatment. Talk to your prescriber, or ask about a dermatologist, if:
Do not stop or lower your dose on your own because of hair loss. In the Zepbound trials no one stopped for this reason. Bring it up with your prescriber, who can weigh it against how the drug is working for you.
We are not listing supplements or treatments here. The labels and studies above do not show that any supplement prevents or fixes GLP-1-related shedding.
Because shedding lags the trigger by months, it helps to have dates. Note when you started, each dose change, your weight, and the week you first noticed more hair in the brush or drain. Dose Track lets you log each dose, record side effects like hair shedding as they happen, and track weight alongside, so you can show your prescriber a clear timeline instead of a guess. Our guide to tracking GLP-1 doses and side effects covers what to write down, and GLP-1 side effects week by week covers what tends to show up earlier.
This article is general information, not medical advice. Talk to your prescriber before you start, change or stop any medicine.