The quantity of weakly bound proteins in the hair shaft was estimated in patients with androgen-dependent alopecia and telogen hair loss. Hair protein assessment by 240-nm absorbance was shown to have advantages over Lowry's method and biuret test. Significant rises in the levels of weakly bound proteins and in the rate of their elution were first found in patients with androgen-dependent alopecia in the hair of the parietal region as compared to that in the occipital region. At the same time the rate of hair protein elution in the parietal area was higher in the patients with androgen-dependent alopecia than that in healthy volunteers. The patients with telogen hair loss displayed higher protein elution rates predominantly in the occipital region; however, they exhibited no significant differences in the total amount of weakly bound proteins as compared to the healthy volunteers.