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BRIEF REPORT
Risk of new-onset hair loss with 
semaglutide and tirzepatide:
A TriNetX cohort study
The widespread use of glucagon-like peptide-1 recep-
tor agonists (GLP-1RAs) for type 2 diabetes and obesity 
has prompted investigation into their dermatologic 
side effects, including hair loss. 1 Prior studies have 
associated semaglutide and tirzepatide with potential 
hair loss. 2-4 This retrospective population-based cohort 
study used TriNetX, a multicenter database of 
de-identified electronic medical records, to evaluate 
whether patients treated with semaglutide and tirzepa-
tide developed new-onset hair loss.
We included patients $18 years old with 2 or more 
instances of tirzepatide or semaglutide prescriptions. 
To avoid confounding, we excluded patients with a 
history of chemotherapy or immunosuppressant ther-
apy. This cohort was compared with patients on 
metformin who had never been treated with 
GLP-1RAs. Cohorts were propensity score-matched 
(PSM) for age, race, gender, ethnicity, BMI, overweight 
and obesity, polycystic ovarian syndrome, type 2 
diabetes mellitus, hypothyroidism, hyperlipidemia, 
hypertension, iron deficiency anemia, iron deficiency, 
nutritional deficiencies, spironolactone use, and finas-
teride use. Outcomes of interest were new-onset 
telogen effluvium (TE) (ICD-10 L65.0), anagen efflu-
vium (AE) (ICD-10 L65.1), alopecia areata (AA) (ICD-
10 L63), androgenetic alopecia (AGA) (ICD-10 L64), 
and other non-scarring hair loss (ONSH) (ICD-10 L65). 
Patients with the outcomes of interest prior to the
analysis window were excluded. We calculated risk 
ratios and 95% confidence intervals at 6 months, 1 year, 
and anytime after the index event and evaluated BMI 
longitudinally after the index event.
We ran 2 analyses using the TriNetX US database 
and the TriNetX worldwide database. After PSM, the US 
analysis had 576,250 patients in each cohort (total 
n = 1,152,500) and the worldwide analysis had 619,732 
patients in each cohort (total n = 1,239,464). Increased 
risk of TE 1 AE emerged by 1 year and persisted in both 
analyses. Increased risk of AA, AGA, and ONSH were 
noted as early as 6 months, with progressively higher 
RRs at 1 year and anytime-after (Table I). Notably, 
results were consistent between both analyses. BMI 
changes over follow-up were modest and comparable 
between the GLP-1RA and control cohorts (Table II). 
In this large, PSM cohort study, use of semaglutide 
and tirzepatide was associated with a significantly 
increased risk of AE, TE, AGA, AA, and ONSH. Burke 
et al observed similar findings, with increased hair 
loss rates among GLP-1RA users. Semaglutide 
showed high odds for AGA, and tirzepatide demon-
strated a borderline association with TE. 3 Godfrey 
et al also identified increased reporting odds of 
alopecia with semaglutide and tirzepatide. 4 Our 
findings support prior pharmacovigilance reports. 
Consistency across alopecia types and agents sug-
gests a drug-related effect. Observed BMI reductions 
in our study were modest over time, suggesting that 
the risk of hair loss may not be fully explained by 
rapid or extreme weight loss alone (Table II).
Table I. Risk ratios (RR) and 95% confidence intervals (CI) after propensity score matching
Outcome 1 
ICD-10 codes
RR (95% CI)
TriNetX US database TriNetX Worldwide database
6 mo 1 y Anytime 6 mo 1 y Anytime
Telogen effluvium
1 Anagen 
effluvium 
1.30 (0.98-1.71) 1.77 (1.45-2.16) 2.42 (2.10-2.79) 1.12 (0.84-1.48) 1.78 (1.47-2.17) 2.42 (2.11-2.78)
Other nonscarring 
hair loss 
1.591 (1.48-1.70) 1.98 (1.89-2.09) 2.14 (2.07-2.22) 1.67 (1.56-1.79) 2.09 (1.99-2.20) 2.18 (2.11-2.26)
Alopecia areata 1.42 (1.02-2.01) 1.53 (1.18-1.98) 1.72 (1.45-2.06) 1.44 (1.04-2.00) 1.62 (1.26-2.09) 1.72 (1.45-2.04)
Androgenetic
alopecia
1.79 (1.45-2.20) 1.96 (1.68-2.28) 2.41 (2.17-2.67) 2.01 (1.62-2.48) 2.10 (1.80-2.45) 2.58 (2.32-2.86)
Cohort sizes: TriNetX US database = 576,250 matched patients per group (total n = 1,152,500); TriNetX Worldwide database = 619,732 
matched patients per group (total n = 1,239,464).
© 2026 The Author(s). Published by Elsevier Inc. on behalf of the 
American Academy of Dermatology, Inc. This is an open access 
article under the CC BY license (http://creativecommons.org/ 
licenses/by/4.0/).
J AM ACAD DERMATOL ■ 2026 1
http://creativecommons.org/licenses/by/4.0/
http://creativecommons.org/licenses/by/4.0/
http://creativecommons.org/licenses/by/4.0/
Limitations include inability to assess severity of hair 
loss, lack of trichoscopic findings, reliance on ICD-10 
coding, and retrospective data analysis. Although we 
performed a worldwide analysis, data may not be 
fully generalizable to populations with different pre-
scribing practices, healthcare access, or demographic 
characteristics. Prospective dermatologic studies are 
needed to elucidate our findings. Clinicians should 
consider counseling patients on the possibility of hair 
loss with semaglutide and tirzepatide use.
Henry O. Herrera, BS, a and Jeremy S. Bordeaux, 
MD, MPH b
From the Department of Dermatology, Case West-
ern Reserve University, Cleveland, Ohio a ; and 
Department of Dermatology, University Hospitals 
Cleveland Medical Center, Case Western Reserve 
University, Cleveland, Ohio. b
Funding sources: None.
Patient consent: Not applicable. 
IRB approval status: Not applicable.
Key words: alopecia; androgenetic alopecia; elec-
tronic health records; GLP-1 receptor agonist; 
hair loss; semaglutide; telogen effluvium; 
tirzepatide.
Correspondence to: Henry O. Herrera, BS, Depart-
ment of Dermatology, Case Western Reserve 
University, School of Medicine, 9501 Euclid 
Ave, Cleveland, OH 44106
E-mail: hoh2@case.edu
Conflicts of interest
None disclosed.
REFERENCES
1. Tran MM, Mirza FN, Lee AC, Goldbach HS, Libby TJ, Wisco OJ. 
Dermatologic findings associated with semaglutide use: a 
scoping review. J Am Acad Dermatol. 2024;91(1):166-168. 
https://doi.org/10.1016/j.jaad.2024.03.021
2. Desai DD, Sikora M, Nohria A, et al. GLP-1 agonists and hair 
loss: a call for further investigation. Int J Dermatol. 2024;63(9): 
1128-1130. https://doi.org/10.1111/ijd.17246
3. Burke O, Sa B, Cespedes DA, Sechi A, Tosti A. Glucagon-like 
peptide-1 receptor agonist medications and hair loss: a 
retrospective cohort study. J Am Acad Dermatol. 2025;92(5): 
1141-1143. https://doi.org/10.1016/j.jaad.2025.01.046
4. Godfrey H, Leibovit-Reiben Z, Jedlowski P, Thiede R. Alopecia 
associated with the use of semaglutide and tirzepatide: a 
disproportionality analysis using the FDA adverse event reporting 
system (FAERS) from 2022 to 2023. J Eur Acad Dermatol Venereol. 
2025;39(2):e153-e154. https://doi.org/10.1111/jdv.20197
https://doi.org/10.1016/j.jaad.2026.02.042
Table II. Mean body mass index at index event and follow-up
Cohort
TriNetX US database
6 mo 1 y Anytime
GLP-1RA BMI at index event 
37.20 6 7.97
35.94 6 7.85 35.39 6 7.88 34.76 6 7.87
Control BMI at index event 
33.90 6 8.48
32.58 6 7.74 32.46 6 7.71 32.22 6 7.71
J AM ACAD DERMATOL
■ 2026
2 Brief Report
mailto:hoh2@case.edu
https://doi.org/10.1016/j.jaad.2024.03.021
https://doi.org/10.1111/ijd.17246
https://doi.org/10.1016/j.jaad.2025.01.046
https://doi.org/10.1111/jdv.20197
https://doi.org/10.1016/j.jaad.2026.02.042
	Risk of new-onset hair loss with semaglutide and tirzepatide: A TriNetX cohort study
	Conflicts of interest
	References