Kovacevic M, et al. - Researchers conducted this single-blinded crossover study to explore a novel mechanism to contract the arrector pili muscle, as well as to report on the anti-shedding effectiveness of a shampoo containing a selective trace amine-associated receptors (TAAR) agonist, tyramine hydrochloride. Investigators found that the novel TAAR shampoo decreased hair shedding during brushing by 31% in a cohort of 24 women with a maximum decline of 77%. It has been demonstrated that a shampoo formulated with a selective TAAR agonist contracts the arrector pili muscle and lessens hair shedding after washing.