Evidence showed up to a 1200% increase in hair growth over the study period.This particular study, of lactobacillus reuteri ATCC PTA 6475 (L. reuteri) showed murine results that would be astonishing if they transferred. Evidence showed up to a 1,200% increase in hair growth over the study period. Humans have an average of 130 hair follicles per square centimeter of scalp (scalp total lows of 80,000 for redheads, and peaks of 140,000 for blondes, as well as everything in between). Generally follicles are 90% active, and 10% shedding or quiescent (resting). Now if a person only has 10 hairs growing per square centimeter, a 1200% increase would add 120 hairs (total 130) making them completely average. That is an exciting result though, so far, no human testing has been officially attempted. The interesting thing about this study is that there is no esoteric or complicated equipment or procedures involved. It uses nothing that is toxic to humans. Best of all, you can obtain all the materials easily and perform your own testing at home. It is highly unusual for research like this to be so accessible!