GLP-1 side effects hair loss
You are dealing with a symptom and want to know if it is expected.
Reference and calculator, not medical advice. Dosing figures below are transcribed from FDA-approved prescribing information and link back to it. Last reviewed August 2026.
Hair loss sits in an unusual position among the reactions listed for these medications. It is common enough to appear in Zepbound's list of reactions reported in at least 5% of patients, and it appears in Wegovy's main adverse-reaction table — but unlike almost everything else on those lists, it is not gastrointestinal and does not cluster around dose increases.
Listed in the prescribing information
Common adverse reactions listed for GLP-1 receptor agonists as a class.
- NauseaMost commonly reported; typically worst after a dose increase.
- DiarrhoeaGastrointestinal effects are the most frequently listed category.
- VomitingReported more often at higher doses.
- ConstipationRelated to slowed gastric emptying.
- Abdominal painListed across the class.
- Injection site reactionsApplies to injectable products only.
- FatigueListed in product labelling.
- HeadacheListed in product labelling.
These products carry a boxed warning regarding thyroid C-cell tumours observed in rodent studies, and are contraindicated in people with a personal or family history of medullary thyroid carcinoma or MEN 2. Read the full prescribing information for your specific product and discuss it with your prescriber — this summary is not complete and is not a substitute for that document.
That difference matters for how you read it. The gastrointestinal reactions are the reason the titration schedule is stepped, and they follow the schedule. Hair loss does not behave that way in the data — what it tracks with, according to both labels, is weight reduction.
What each label actually reports
Incidence figures come from the adverse-reaction sections of the prescribing information. The two weight-management products report trial data; the diabetes products list alopecia only as a postmarketing report.
| Product | Reported in | Women | Men |
|---|---|---|---|
| Wegovy Semaglutide | Clinical trials | 4% | 0.9% |
| Zepbound Tirzepatide | Clinical trials | 7.1% | 0.5% |
| Ozempic Semaglutide | Postmarketing reports only | no denominator | no denominator |
| Mounjaro Tirzepatide | Postmarketing reports only | no denominator | no denominator |
| Rybelsus Semaglutide (oral) | Postmarketing reports only | no denominator | no denominator |
| Saxenda Liraglutide | Postmarketing reports only | no denominator | no denominator |
| Trulicity Dulaglutide | Postmarketing reports only | no denominator | no denominator |
A postmarketing entry means the reaction has been reported after approval but the label gives no rate, because spontaneous reports have no denominator. It is not evidence that the rate is lower — only that it was not measured. Every figure above is checked against the label linked at the foot of this page.
The other thing that sets it apart is the sex split. Nothing else in these adverse-reaction tables is broken out by sex, because nothing else showed a difference worth reporting. Hair loss did — 8.4% versus 0.2% at the highest Wegovy dose — which is why both manufacturers reported it that way.
Common questions
- How does it rank against nausea?
- Not close. Nausea was reported by 35–39% of people in the Wegovy trials against 3–6% for hair loss. Hair loss is prominent in discussion far out of proportion to its reported frequency, which is worth knowing before you worry about it.
- Does it show up at the same time as the GI effects?
- The labels do not give timing for it, unlike the escalation-linked pattern that shapes the titration schedule. That is one of several things these documents simply do not record.
- Is it in the boxed warning?
- No. The boxed warning concerns thyroid C-cell tumours seen in rodent studies and is a contraindication to screen for before starting. Hair loss is an adverse reaction reported during trials, an entirely separate category.
Sources and last review
Every dosing figure on this page is transcribed from an FDA-approved label and links back to it. Conversions are arithmetic you can repeat by hand. Nothing here is reviewed by a clinician, and this site does not employ one — which is exactly why what I do publish stays traceable to its source.
- Zepbound (Tirzepatide) prescribing information — Eli Lilly, label revised 6 May 2026, checked 7 August 2026
- Mounjaro (Tirzepatide) prescribing information — Eli Lilly, label revised 6 May 2026, checked 7 August 2026
- Wegovy (Semaglutide) prescribing information — Novo Nordisk, label revised 30 June 2026, checked 7 August 2026
- Ozempic (Semaglutide) prescribing information — Novo Nordisk, label revised 10 June 2026, checked 7 August 2026
- Rybelsus (Semaglutide) prescribing information — Novo Nordisk, label revised 20 May 2026, checked 7 August 2026
- Saxenda (Liraglutide) prescribing information — Novo Nordisk, label revised 15 June 2026, checked 7 August 2026
- Trulicity (Dulaglutide) prescribing information — Eli Lilly, label revised 25 March 2026, checked 7 August 2026
Transcribed from the labels above and checked by me — Gavin, who builds this site, takes a GLP-1, and is not a clinician. Last reviewed August 2026. Found an error? [email protected] — I treat corrections as bugs. How this site is built and funded.
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