A large cohort analysis finds higher risks of telogen effluvium and androgenic alopecia in patients on GLP-1 agonists, raising new questions for dermatologists.
Glucagon-like peptide-1 receptor agonists may be linked to an increased risk of nonscarring hair loss, according to findings from a large real-world retrospective analysis.
The research was presented as a poster at the recent annual EADV Congress held in Paris.
While these agents are known for their metabolic and anti-inflammatory benefits, reports have emerged suggesting an association with hair loss, though data to date have been conflicting, the researchers said.
Some anecdotal observations indicate worsening hair shedding, while others suggest potential improvement in hair growth.
The researchers conducted a retrospective cohort study using the TriNetX US Collaborative Network to examine the incidence of nonscarring hair loss disorders in patients receiving GLP-1 RA therapy.
The study included 547,993 adults who had filled at least two prescriptions for a GLP-1 RA between 2014 and 2024.
Matched controls, who had no history of GLP-1 RA use, were required to have at least two general health visits during the same period.
Individuals with pre-existing hair loss or diagnoses likely to confound hair loss outcomes, including thyroid disease, menopause, chemotherapy exposure, autoimmune disease or scarring alopecia, were excluded.
Outcomes of interest included incident diagnoses of telogen effluvium, androgenetic alopecia, alopecia areata and overall nonscarring hair loss.
Propensity score matching was performed for demographic and clinical variables including age, sex, race and ethnicity, BMI and diabetes status.
The analysis revealed that incidence rates of nonscarring hair loss were consistently higher among GLP-1 RA users compared with controls. Telogen effluvium incidence increased 5.1-fold in GLP-1 RA users versus 3.8-fold in controls, while androgenic alopecia rose 21.4-fold in GLP-1 RA users compared with 18.3-fold in controls.
Alopecia areata incidence also increased, but the difference between groups was not statistically significant.
Overall nonscarring hair loss incidence rose 4.6-fold in GLP-1 RA users and 3.4-fold in controls.
At six months, GLP-1 RA use was significantly associated with androgenic alopecia and overall nonscarring hair loss, but not alopecia areata. By one year, associations with telogen effluvium, androgenic alopecia and overall hair loss all reached statistical significance, while alopecia areata remained nonsignificant.
The researchers said their findings suggested that GLP-1 RA use may independently increase the risk of certain types of hair loss, particularly telogen effluvium and androgenic alopecia.
“Clinicians should counsel patients about the possibility of hair shedding prior to GLP-1 RA initiation, particularly in those expected to see rapid weight loss,” they noted.
“Although causality cannot be established from observational data, these findings highlight the need for clinical awareness and further mechanistic investigation.
“Multidisciplinary care is critical as GLP-1 RA become integral to obesity and diabetes management.”
Australian dermatologist Professor Rod Sinclair, regarded as a leading world expert on hair loss, told Dermatology Republic this finding did not come as a surprise.
“It’s been quite tricky to separate how much of the telogen effluvium is caused by the weight loss and how much is caused by the drug, because we know that when people have massive weight loss from any cause, they also get a telogen effluvium,” he said.
“We’ve seen it with gastric bypass surgery. We see it in the whole range of scenarios, and so it’s not unique to these drugs, but they do cause telogen effluvium, and if you do get telogen elevator, that might trigger an androgenetic alopecia.”
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The good news was that it was treatable, with the use of drugs like minoxidil being shown to work in in telogen effluvium and hair shedding, said Professor Sinclair, who is also editor of Dermatology Republic.
Professor Sinclair and colleagues recently published a paper Clinical and Experimental Dermatology on the topic of telogen effluvium unmasking androgenetic alopecia.
“What we’ve just recently shown in one of our publications is it doesn’t just unmask because it actually causes it,” he told DR.
Titled “You cannot go bald without first, losing your hair: Telogen effluvium is a precursor to, prerequisite for and potentially an incitant to common baldness in men”, the paper detailed the study of men aged 18 to 55 years with moderate to advanced balding, using detailed imaging to track individual hairs over time.
The researchers found that hairs in balding areas enter a shorter growth phase, known as anagen, before any reduction in thickness occurs.
This shortening of the growth phase manifests clinically as TE, even if shedding goes unnoticed, especially in men with short hair.
Later, the hairs begin to thin through a process called follicular miniaturisation, which leads to the visible patterns of baldness characteristic of androgenetic alopecia.
The researchers said their findings suggested that TE was not just a temporary condition but a precursor and possible trigger for permanent hair loss, offering a new model for understanding how male baldness develops and emphasising that shedding often occurs years before thinning becomes apparent.
