Lactic acid is the most widely occurring acid in nature. In the form of lactate it is a normal constituent of the human organism and an important intermediate product of metabolism, for example as a product of the breakdown of sugar through lactic acid fermentation. Lactic acid is present in sweat, muscle blood serum, in the kidney and the gall bladder, and in saliva. It is contained in almost all shampoos, in many cosmetic products, foodstuffs (e.g. pickled cucumbers, pickled cabbage, and sour dough, …). The antiseptic effect of lactate protects the skin against disease-causing agents. The formation and subsequent breakdown of lactic acid in the body following sport is responsible for the familiar feeling of muscle soreness. The highly diluted lactic acid solution which is administered on the body in the Skinial method is broken down (synthesised) automatically and without leaving any residues within 30 minutes of it producing its effects (i.e. the repulsion of the pigment molecules).