New hair treatment composition comprising L-carnitine or L-carnitine derivatives

The present invention relates to a hair treatment composition comprising at least one compound which is selected from L-carnitine or L-carnitine derivatives. Furthermore, the invention relates to a method for the extracorporeal analysis of hair follicle cells, to a method for the extracorporeal determination of the ATP synthesis rate in hair follicle cells, further to a test method for demonstrating the effectiveness of cosmetic or pharmaceutical agents to maintain or promote the homeostasis of the hair follicle and for the treatment of pathological conditions of the hair follicle as well as a screening method for the identification of cosmetic or pharmaceutical agents to maintain or promote the homeostasis of the hair follicle and for the treatment of pathological conditions of the hair follicle and a method for preparing a cosmetic or pharmaceutical composition to maintain or promote the homeostasis of the hair follicle or for the treatment of pathological conditions of the hair follicle.