Hair loss is on all four labels: Ozempic, Wegovy, Mounjaro and Zepbound

Hair loss on each label

Semaglutide is the drug in Ozempic and Wegovy, and tirzepatide is the drug in Mounjaro and Zepbound. The two labels approved for weight reduction measured hair loss in placebo-controlled trials. The two diabetes labels print no hair loss figure from their trials at all.

Don’t rank the Wegovy and Zepbound numbers against each other. They come from different trials in different people, and the Zepbound label says so in the first line of its trial results: “adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug”. Each label’s stomach side effects are set out the same way on side effect rates, label by label.

Wegovy

Wegovy’s table reports hair loss in 3% of adults on 2.4 mg and 1% on placebo. A pooled figure in the text beneath it, from Studies 2, 3 and 4, is 3.3% against 1%, and it splits by sex: 4% of women and 0.9% of men on Wegovy reported hair loss, against 2% of women and no men on placebo.

The rate is higher at 7.2 mg, the top injection dose. In the two 72-week trials that tested it against both placebo and 2.4 mg, hair loss was reported by 5.8% of patients on 7.2 mg, 3.3% on 2.4 mg and 1.0% on placebo. Among women the figures were 8.4%, 5.4% and 1.5%. Among men they were 0.2%, zero and zero. In the 7.2 mg group, one hair loss event ended treatment, one paused it and five led to a lower dose; none did on 2.4 mg or placebo. Who can move up to 7.2 mg is on the dose escalation schedules.

Teenagers were studied too. In the trial of patients aged 12 and older, 4% on Wegovy reported hair loss and none on placebo. The 25 mg Wegovy tablet has no hair loss figure of its own: the label says only that the common adverse reactions in its trial were “similar to those listed in Table 3”.

Zepbound

Zepbound’s table shows hair loss in 5% of adults on 5 mg, 4% on 10 mg and 5% on 15 mg, against 1% on placebo, pooled from two trials of up to 72 weeks. Within that table the rate is flat across the three doses.

It was reported mostly by women. On Zepbound, 7.1% of women had hair loss against 0.5% of men; on placebo, 1.3% of women and no men. Nobody on Zepbound stopped treatment because of it, and one person on placebo did.

Two further Zepbound trials, in adults with obstructive sleep apnea and obesity, reported adverse reactions “similar to those reported in the two pooled placebo controlled clinical trials for weight reduction”, with no separate hair loss figure.

Ozempic and Mounjaro

Ozempic and Mounjaro are the diabetes labels, and neither trial table has a hair loss row. Both tables list reactions reported by at least 5% of treated patients. Ozempic adds a shorter list of reactions seen in more than 0.4% (fatigue, dysgeusia and dizziness), and hair loss isn’t on it. Mounjaro reports rarer reactions in its text, down to dysgeusia at 0.1%, and hair loss isn’t there either.

Where both labels do list it is section 6.2, under “Skin and Subcutaneous Tissue”: alopecia, among reactions reported after the drug went on sale. Both labels are plain about the limits of that list. Because the reports are voluntary, “it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.”

Ozempic and Wegovy are the same molecule, as are Mounjaro and Zepbound. That doesn’t let a weight label’s figure stand in for the diabetes label. The doses, the patients and the trials differ, and neither diabetes label borrows the weight label’s number.

What the labels leave out

The two weight labels give one line of explanation, and it’s the same line.

Wegovy: “Hair loss adverse reactions in WEGOVY injection-treated patients were associated with weight reduction.” Zepbound: “Hair loss adverse reactions in ZEPBOUND-treated patients were associated with weight reduction.”

That’s where they stop. Neither says what it is about weight reduction that brings hair loss on, whether the hair grows back, or whether anything prevents it, and hair loss isn’t among the warnings in section 5 of any of the four labels. Ozempic and Mounjaro list alopecia and tie it to nothing.

None of this covers compounded semaglutide or tirzepatide, which have no FDA label and no trial tables. The same two weight-label tables also carry a fatigue row, read the same way on fatigue on the four labels.

Sources

See the providers

Hair loss is a property of the drug, not the seller. The boards list who sells each molecule and what each one publishes.

• Semaglutide providersprovider board

  Readers who have settled on semaglutide and are choosing who to buy it from.

• Tirzepatide providersprovider board

  Readers who have settled on tirzepatide and are choosing who to buy it from.

More, read from the same labels

• Semaglutide vs tirzepatidereading the label

  What the four FDA-approved labels say each molecule is, what each is approved to treat, and where the two differ.

• How they workreading the label

  The receptor each molecule switches on, what the labels say that does to appetite, blood sugar and the stomach, and why one dose lasts a week.

• Dose escalation schedulesreading the label

  The starting dose, the escalation interval and the maximum dose each label sets, and why they are not interchangeable.

• Side effect ratesreading the label

  What each label reports for nausea, vomiting, diarrhea and constipation — and the sentence every label prints above those numbers.

• Fatigue and tirednessreading the label

  Which labels list fatigue, the rate against placebo where a trial measured it, and what each label counts as fatigue.

• Missed dose rulesreading the label

  The window each label gives for a late dose, and the minimum gap it requires when the injection day changes.

• Drug interactionsreading the label

  Insulin and sulfonylureas, oral medications, and the oral-contraceptive precaution that appears on two of these four labels and not the other two.

• Buying one onlinereading the label

  The agency's own warning signs for a telehealth GLP-1 seller, its 28-day vial rule, and what it says about drugs that arrive warm.

• Refrigeration and storagereading the label

  How cold each pen is kept, how many days it can spend at room temperature, and what the labels say about heat and freezing.

• Who should not take onereading the label

  The boxed warning every one of these labels carries, the two contraindications, and which warnings appear on which product.