1. A method for improving the appearance of hair / fur / feathers / scales of animals, including humans, by the oral administration of nutraceuticals or food compositions containing steviol, a steviol precursor or Stevia extract that contains stevioside and / or rebaudioside A for a sufficient time, and in an amount effective to improve the general appearance of the hair / fur of mammals and to register an improved species. 2. The method according to claim 1, wherein the improvement in appearance is selected from the group consisting of: restoring hair color / fur and delaying graying of hair / fur, and the oral nutraceutical composition or food composition contains steviol. The method of claim 2, wherein the animal is a human. The method of claim 1, wherein the administration is constant. The method of claim 1, wherein the improvement is selected from: reducing hair loss, restoring hair growth after formation of bald patches, increasing hair thickness, counteracting age-related hair thinning, preventing premature hair loss, or delaying or severity of age-related hair loss or thinning .6. The method of claim 5, wherein the animal is a human. The method of claim 5, wherein the administration is constant. The use of steviol, a precursor of steviol or a Stevia extract that contains stevioside and / or rebaudioside A, in the manufacture of an oral nutraceutical composition or food composition that improves the appearance of hair / fur / feathers / scales of animals, including humans. 9. The use of claim 8, wherein the nutraceuticals or food products contain steviol and the improvement is restoration of hair / fur color and / or delayed graying of hair�1. Способ улучшения внешнего вида волос/меха/перьев/чешуи животных, включая человека, заключающийся в оральном введении нутрицевтиков или пищевых композиций, содержащих стевиол, предшественник стевиола или экстракт Stevia, который содержит стевиозид и/или ребаудиозид А в течение достаточного времени, и в количестве, эффект
