The body's internal clock can be determined from a hair sample (opens in new tab)

A research team at Charité–Universitätsmedizin Berlin has developed a test that can determine a person's chronotype based on their hair roots. It is intended to lay the foundation for circadian medicine—that is, medicine that is more closely aligned with the human body's internal clock. Applied to approximately 4,000 people, the new method also reveals that women and men differ slightly in their biological rhythms, and that lifestyle has a greater influence than previously assumed. The result...