New research has linked GLP-1 receptor agonists to hair loss in some patients, with semaglutide showing the strongest association despite falling short of statistical significance in a small study.
Based on the results, doctors should warn patients about potential hair changes when prescribing the agents and encourage them to report any issues, the researchers say.
In their retrospective cohort study of 283 patients taking GLP-1 RAs, the University of Miami team found that 35 patients experienced hair loss. Their analysis showed that patients taking semaglutide were nearly seven times more likely to develop alopecia, though this finding wasn’t statistically significant.
Tirzepatide demonstrated a borderline significant association with telogen effluvium (p=0.0537).
The findings, published in the Journal of the American Academy of Dermatology (link here), revealed that of those experiencing hair issues, only three patients (1%) developed new hair loss during the study period. However, 29 patients (12%) with pre-existing hair loss reported worsening symptoms after starting GLP-1 RAs.
Among those experiencing hair loss, the most common diagnoses were androgenic alopecia (8%) and telogen effluvium (4%), with smaller numbers reporting unspecified hair loss or alopecia, they added.
The study included a predominantly female cohort (65%), with a mean age of 56 years. Most patients (83%) received semaglutide, while 46% used tirzepatide, 22% dulaglutide, and 12 liraglutide. The researchers noted that many patients tried multiple GLP-1 RAs throughout the study period.
The findings echoed earlier research examining FDA adverse event reports, which also identified semaglutide and tirzepatide as standout medications for hair-related side effects.
The study authors suggested that “the lack of statistical significance in both studies is likely a function of insufficient power, and that the frequency of GLP-1RA-associated hair loss is likely lower than expected.”
“Widespread adoption of GLP-1 RAs has spurred interest in their potential impact on hair health,” they wrote.
“One theory suggests they may disrupt normal hair follicle cycles, potentially leading to conditions such as telogen effluvium or androgenetic alopecia. Another theory posits GLP-1 RAs may confer benefits by improving insulin sensitivity and enhancing scalp blood flow.”
“Despite these opposing viewpoints, the clinical evidence remains sparse.”
The researchers acknowledged several limitations, including the study’s retrospective design, reliance on self-reported data, and relatively small sample size. They also noted the absence of data on treatment duration, indication, and degree of weight loss.
“While the clinical evidence remains inconclusive, the potential for GLP-1 RAs to impact hair health cannot be dismissed,” they wrote.
“Clinicians should encourage patients to report any changes in hair and consider these factors when initiating GLP-1 RA therapy.
“Future research should aim to explore the mechanistic underpinnings of GLP-1 RA related hair loss, focus on hair adverse effects with larger sample sizes, and more comprehensive data collection.”