NEW DELHI: The kilos may be coming off, but for some men, there could be another unwelcome change in the mirror — thinning hair.
A new study has found a genetic link between the activity targeted by popular GLP-1 weight-loss drugs and male-pattern hair loss, raising the possibility that some men may be more vulnerable to hair shedding while using medicines such as Ozempic, Wegovy and Zepbound.
Researchers from NYU Langone Health found that men who were already genetically predisposed to androgenetic alopecia — the common inherited form of male-pattern baldness — had an additional 7% risk of hair loss associated with GLP-1 activity.
The finding is important because thinning hair has been widely reported by people taking GLP-1 medicines, but until now scientists had not been able to establish a clear genetic connection.
The study, published online on September 3 in the Journal of Investigative Dermatology, does not mean that everyone taking a GLP-1 drug will lose hair. Nor does it establish that the medicine directly causes baldness. Instead, it provides evidence that there may be a biological connection that deserves further investigation.
Hair shedding among people losing weight rapidly is not entirely new. Doctors have previously suspected that the sudden drop in body weight associated with GLP-1 medicines may push some hair follicles into a resting phase. This can lead to increased shedding several weeks or months later.
The good news is that this type of shedding can often improve once weight stabilizes.
But the new study raises another possibility: for men who are already genetically programmed to develop male-pattern baldness, GLP-1-related biological activity may add to that risk.
Researchers focused on the GLP1R gene, which influences the body’s production of receptors for GLP-1, the hormone targeted by these medicines.
They compared genetic information from large databases with genetic patterns seen in men with androgenetic alopecia — hair loss that typically begins around the hairline and crown and gradually becomes more pronounced.
The researchers found that genetic variants associated with greater GLP-1 receptor activity were more likely to occur in men with male-pattern hair loss.
Importantly, the researchers tested whether the association could simply be explained by other health problems.
They adjusted their analysis for blood pressure, which can affect blood flow, and researchers have linked it to hair loss. The 7% additional risk remained.
They also examined other possible factors, including insulin resistance and low testosterone levels. Again, the association persisted.
“This is the first genetic link between GLP-1 use and an increased risk of male-pattern hair loss from androgenetic alopecia,” said senior investigator Lynn Petukhova of NYU Grossman School of Medicine.
She said the finding could help doctors identify people who may be more vulnerable to hair loss. This would occur before prescribing GLP-1 medicines.
Clinicians are increasingly using GLP-1 medicines to treat obesity and type 2 diabetes, conditions that carry substantial health risks. The study does not recommend stopping treatment and does not establish that GLP-1 medicines directly cause permanent baldness.
Instead, it adds another issue for doctors and patients to discuss.
People taking these drugs may experience rapid weight loss that influences hair growth. Nutritional changes and underlying genetics also contribute, while the medicine’s biological effects may overlap with these factors.
The medicine alone is not responsible for hair shedding.
However, as the study looked only at men, there is another important limitation.
The researchers were able to study male-pattern hair loss more clearly because the condition has been extensively studied in men. As a result, the current analysis focused on men, said the researchers.
Whether the same genetic relationship exists in women remains unknown, they said.
The researchers plan to investigate that question next.
The findings could eventually change how doctors approach patients worried about losing hair while undergoing obesity treatment.
Petukhova noted that future studies might verify the link. Once verified, clinicians could identify individuals at higher risk prior to treatment. They would then consider methods to safeguard hair.
Researchers used large publicly available genetic databases in the study. One held data from more than 31,000 people, and another included more than 205,000, mostly White men. Researchers should validate the findings across more diverse populations before broad application.
The findings add to a growing understanding. Successful obesity treatment is not simply about watching the number on the weighing scale. Thus, it requires broader health improvements.
When weight drops rapidly, the body undergoes multiple changes. Rapid weight loss affects appetite, metabolism, hormones, muscle mass, nutritional intake, and even hair growth.
Doctors should look beyond how many kilograms people on GLP-1 medicines have lost.
