Results: After exclusion of patients with a disease or on drugs known to cause hair loss, 823 women remained. Analysis of trichograms demonstrated annual periodicity in the growth and shedding of hair, manifested by a maximal proportion of telogen hairs in summer. A second peak seems to exist, though it is less pronounced, in spring. The telogen rates were lowest in late winter. Kunz, M., Seifert, B., & Trüeb, R. M. (2009). Seasonality of hair shedding in healthy women complaining of hair loss. Dermatology (Basel, Switzerland), 219(2), 105–110. https://doi.org/10.1159/000216832