TLDR Hair growth cycles in Chileans vary seasonally, with more hair resting in summer and growing in winter.
The study of 514 trichograms from Chilean residents revealed a seasonal variation in hair follicle phases, with a significant increase in the telogen (rest) phase to 20%±10% during summer and a decrease to 16%±10% in winter. Conversely, the anagen (growth) phase decreased to 80%±10% in summer and increased to 83%±10% in winter. These findings suggested a clear seasonal pattern in hair growth cycles, potentially influenced by temperature, sunlight, and hormonal changes, with more hair in the resting phase during summer and more in the growth phase during winter.
224 citations
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