Hair loss and GLP-1 medications

Which labels mention hair loss

• In the clinical trial section (6.1), with rates: Wegovy® (semaglutide), Zepbound® (tirzepatide) and Foundayo™ (orforglipron). All three are approved for weight reduction ^[1][5][8].
• Only in the postmarketing section (6.2), as alopecia, without a rate: Ozempic® and Rybelsus® (semaglutide), Mounjaro® (tirzepatide) and Saxenda® (liraglutide) ^[2][3][4][7].
• In the Medication Guide’s list of most common side effects: Wegovy® and Zepbound® ^[1][6].

Trial rates against placebo

The rows below come from each US label’s placebo-controlled trials in adults with obesity or overweight. Ranges cover dose groups. Section 6.1 of each label warns that rates from different trials cannot be directly compared.

European and Canadian product information

The European Medicines Agency classes hair loss as “common”, meaning at least 1 person in 100, for Wegovy® and for Mounjaro®, where it applies mainly to people treated for overweight or obesity ^[9][10]. The European Ozempic® information does not list hair loss in its table. There is no European Zepbound® document, because tirzepatide is sold in the EU only as Mounjaro®.

The European Wegovy® figures come from a slightly different pool from the US table: 2.5% on semaglutide versus 1.0% on placebo across STEP 1 to 4, and 5.3% versus 1.0% on the 7.2 mg dose. The events were mainly mild, most people recovered while continuing treatment, and hair loss was reported more often in people with greater weight loss of 20% or more ^[9].

The Canadian Zepbound® monograph reports 4.2% to 5.1% across doses versus 0.8% on placebo in SURMOUNT-1 and -2. All of these events were mild or moderate, and no one on Zepbound® stopped treatment because of hair loss ^[11].

A large gap between women and men

Every US label that gives hair loss rates splits them by sex, and the difference is striking. In the Wegovy® 2.4 mg pool, hair loss was reported by 4% of women and 0.9% of men on the medicine, against 2% of women and no men on placebo. In the 7.2 mg trials, the figures were 8.4% of women and 0.2% of men ^[1].

The Zepbound® label reports 7.1% of women versus 0.5% of men on the medicine, and 1.3% of women versus no men on placebo. The Foundayo™ label reports 7% of women versus 0.9% of men, and 3% versus 0.7% on placebo. In a Wegovy® trial in adolescents aged 12 and older, hair loss was reported by 4% on the medicine and none on placebo ^[1][5][8].

“Associated with weight reduction”

The Wegovy®, Zepbound® and Foundayo™ labels use the same phrase: hair loss reactions were associated with weight reduction ^[1][5][8]. The US labels do not explain a mechanism, and they do not say whether the hair grows back or how long shedding lasts. The European Wegovy® information goes a step further on both points, as described above ^[9].

The labels also report how often hair loss changed treatment. In the Zepbound® trials, no one on the medicine and one person on placebo stopped because of it. In the Wegovy® 7.2 mg group, one event led to stopping, one to a pause and five to a dose reduction, with none of these in the 2.4 mg or placebo groups ^[1][5].

What postmarketing reports and studies add

For Ozempic®, Rybelsus®, Mounjaro® and Saxenda®, alopecia appears only in section 6.2. The labels explain that these reports are voluntary and come from an unknown number of users, so their frequency often cannot be estimated reliably and a causal link to the medicine cannot always be shown. A listing there means the event was reported often enough to be included, not that a rate is known ^[2][3][4][7].

A 2026 study of the FDA Adverse Event Reporting System from 2022 to 2025 compared how often hair loss was reported with six GLP-1 medicines. Semaglutide was reported with hair loss somewhat more often than expected (adjusted reporting odds ratio 1.23), while tirzepatide showed lower or non-significant signals ^[12]. This kind of analysis counts reports, so it cannot give a rate or prove that a medicine causes hair loss.

A 2025 systematic review found only five relevant studies, mostly of tirzepatide, with conflicting results, and called for more research ^[13]. In short, the best numbers remain the placebo-controlled figures in the labels.

Why it may happen

What the labels support: hair loss was associated with weight reduction, and in the European Wegovy® data it was more frequent with greater weight loss ^[1][5][9].

What is proposed but not measured: shedding after rapid weight loss fits the pattern of telogen effluvium. None of the labels names that condition, and the trials did not examine the hair itself, so this remains an explanation rather than a finding.

General medical background: Cleveland Clinic describes telogen effluvium as temporary shedding that follows a strain or change in the body, including rapid weight loss and restrictive diets. Many growing hairs move into the resting phase at once and fall out, usually two to three months after the trigger ^[14]. MedlinePlus adds that the shedding tends to lessen over six to eight months, though it can sometimes become long-term ^[15].

What else could it be

MedlinePlus lists many causes of hair loss that have nothing to do with GLP-1 medicines: inherited pattern hair loss, which comes on gradually; high fever, major illness, surgery or childbirth; severe emotional stress; crash diets without enough protein; thyroid disease, anaemia and hormone changes; and medicines including retinoids, birth control pills, beta-blockers, calcium channel blockers, some antidepressants and anti-inflammatory painkillers such as ibuprofen ^[15].

Patchy bald spots, a red or scaly scalp, or pain and itching point to other conditions, such as alopecia areata or a scalp infection, rather than diffuse shedding ^[14][15].

What may help

The Medication Guides do not give hair care or diet advice for hair loss. Their general advice applies: raise any side effect that troubles you or keeps going with your healthcare provider. You can also report side effects to the FDA, as the guides explain ^[1][6]. General sources add the following; they are written for hair loss in general, not for GLP-1 medicines.

• For shedding after illness or medicine use, MedlinePlus says no treatment is usually needed and hair tends to grow back; a change of hairstyle or a covering can help in the meantime ^[15].
• Cleveland Clinic advises avoiding extreme or restrictive diets, which can cause nutritional gaps, and managing stress and sleep ^[14].
• Ask your healthcare provider before adding supplements. If you are low in a particular vitamin or mineral, MedlinePlus says your provider may suggest one ^[14][15].
• Scalp treatments exist, but whether one suits you is for a clinician to judge ^[15].

What to write down

If you notice more hair shedding, note when you first saw it and how many weeks you had been on the medicine. Describe whether it is general thinning or patches, and roughly how it changes over the weeks. Because the labels link hair loss to weight reduction, your weight trend over the same period is useful context, as is anything else that changed at the same time, such as your diet, an illness or other medicines.

Since telogen effluvium tends to appear a couple of months after its trigger, looking back two or three months in your log is often more useful than looking at last week.

Ozempic®, Wegovy®, Rybelsus® and Saxenda® are registered trademarks of Novo Nordisk A/S. Mounjaro® and Zepbound® are registered trademarks and Foundayo™ is a trademark of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by Novo Nordisk or Eli Lilly and Company.

When to get help