The Surface and Internal Features of Pubic Hair: A Comparative Study With Those of Scalp Hair

This study investigated the surface and internal features of pubic hair from Korean males and compared them to scalp hair from the same donors. The researchers found that the cuticle layer of pubic hair has a greater number of scales than that of scalp hair, resulting in a thicker cuticle layer overall. Fourier-transform infrared (FT-IR) spectroscopy analysis showed that the protein in the cortex layer of pubic hair was less affected by exposure to urine or ammonia than the protein in the cortex layer of scalp hair. This suggests that the thicker cuticle layer of pubic hair acts as a physical barrier that protects the hair's internal structure. The secondary and tertiary structures of keratin in the pubic hair cuticle layer are also different from those in scalp hair. The researchers hypothesize that the thickened cuticle layer in pubic hair may have evolved as a defence mechanism against chemical damage from urine, urea, and ammonia.