Ever notice an uptick in hair thinning around the end of fall? If so, you’re not imagining it. Turns out, there’s been a number of scientific studies surrounding the reason why our hair thins and sheds at certain times of the year. Most notably, according to évolis hair biologist Dr. Dominic Burg, is a 2009 study from the University Hospital of Zurich, which found that a seasonal shed actually does happen in late summer and fall leading into winter.
(The authors investigated the hair growth and fall patterns in more than 800 women.) A second study of importance: one from Johns Hopkins and Washington University School of Medicine, done in 2017, which made use of Google Trends data around people searching for terms like “hair loss.” “This indirect approach found the same pattern of summer and fall having the highest incidence hair loss according to search patterns,” says Dr. Burg.
But why does this seasonal shedding happen in the first place? Many physicians believe we hang onto more hair in the summer months in order to provide increased protection from the sun, explains Boca Raton, FL hair restoration specialist Dr. Glenn Charles.
“The body also responds to changes in the amount of daylight. The longer hours of daylight in the summer triggers hair to enter the telogen phase, or resting phase, which will then trigger shedding at the end of that phase, approximately 100 days later, in the fall and early winter,” Dr. Charles explains.