It must be mentioned that a favorable effect on the growth of hair has been reported also by Morganti et al. 1982 [16-17, 18] effect of gelatin-cysteine diet supplement on growth of human hair. The study was double blind, lasted three month, and involved 40 volunteers aged between 20-40 years. The diet of the volunteers was two gram gelatin and 0.8 gram cysteine every day or placebo (starch tablets). The scalp of each participant was carefully examined and the number of follicular sites as well as the number of individual hairs emerging from each site was determined.
The area 1cm X 1cm chosen for the count was between the rear and front vertex according to Moretti subdivision. For the diameter assay, the hair about 200 mg was sampled from around the count areas with the fibers cut off as close to scalp as possible. The sulfur content of hair was determined by oxygen flask method and its thiol content was measured.
The results of this study suggested that the dietary supplementation of gelatin and cysteine combination promoted more intense hair growth and leads to substantial increase in the diameter of the fibers. The corresponding sulfur content of hair implies that it is the high sulfur fraction of hair that is affected the most.