A new study from NYU Langone Health reports that men already genetically predisposed to the most common type of hair loss may face an additional 7 percent risk of losing hair while using GLP-1 drugs such as Ozempic, Wegovy and Zepbound for type 2 diabetes and obesity. The work was published online Sept. 3 in the Journal of Investigative Dermatology.

The condition in question is androgenetic alopecia, the inherited hair loss that typically thins the top and front of the scalp. The researchers did not track patients on the drugs at all: they used the GLP1R gene, which influences levels of glucagon-like peptide-1 receptor proteins, as a stand-in for GLP-1 agonist activity, then compared those genetic patterns against the genetics of men with the condition.

Key results

Variants associated with naturally higher levels of GLP-1 receptor proteins turned up more often in men with androgenetic alopecia. The team then adjusted for hypertension, a known hair loss risk factor thought to interfere with blood flow to the scalp, and the extra 7 percent risk held.

Insulin resistance and reduced testosterone were tested next as possible explanations. Neither accounted for the association, and the figure stayed at 7 percent.

Why this is not just weight loss

Shedding has been reported by men and women on these drugs for years, and the usual explanation has been the speed of the weight loss itself, with hair often regrowing several months after weight stabilizes. That explanation was always a little too tidy, and this is the first genetic evidence that something else may also be going on.

"Our study provides the first genetic link between GLP-1 use and an increased risk of male-pattern hair loss from androgenetic alopecia, an association long suspected but until now not shown scientifically," said senior investigator Lynn Petukhova, PhD, of NYU Grossman School of Medicine.

Limitations

This is a database analysis, not a trial of anyone taking the drugs. It drew on the eQTLGen database of 31,684 mostly White men and women and a Complex Traits Genetics database of 205,327 mostly White men, and because male hair loss has been studied far more than female, the causal question could only be examined in men.

Petukhova said more research is needed to work out how GLP-1 activity might interfere with follicle growth, and she plans to look for the same link in women.

Screening before prescribing

The practical hope, and the authors are explicit that it depends on future experiments succeeding, is pre-prescription screening: identifying which patients carry the risk before they start. Petukhova also raised the possibility of GLP-1 users being prescribed combination treatments such as minoxidil, which is a long way from established and worth watching anyway.