Tryptophan in Human Hair: Correlation with Pigmentation
August 2000
in “
Il Farmaco
”
TLDR Men have more tryptophan in their hair than women, and it increases with age and is higher in darker and grey or white hair.
The study analyzed tryptophan levels in 1211 hair samples from healthy individuals to investigate its correlation with hair pigmentation. Results showed that tryptophan levels were higher in males (37.83±3.45 μg/g) than in females (26.62±2.40 μg/g) and varied with age, being highest in early childhood and older age groups. Tryptophan content was also higher in darker hair colors (brown and black) compared to blond hair, and highest in grey and white hair, indicating accumulation with age. The study concluded that tryptophan levels in hair are influenced by sex, age, and hair color.
