Turowski and Adelmann-Grill (79), extensively studied the influence of peptide mo?lecular weight and hair/skin substantivity and found results that openly contrast with those
reported by others (9,10,93).The main findings were the following: (1) dependence of the substan?tivity on the peptide concentration in the medium was almost linear and saturation was
not attained at a concentration below 5%; (2) the amount of protein sorbed to the hair
varied significantly with the washing conditions (amount of water used and rinse duration),
especially when applied in shampoos; (3) the characteristics of the shampoo formulations
strongly influenced both substantivity and permanence of the peptides on the hair after
washing; (4) absorption of peptides on damaged hair was higher than on untreated hair
when at low concentration in the medium and for short incubation time;