Ecdysterone is a dietary supplement which contains the phytoecdysteroid beta-ecdysterone, extracted from the plant Rhaponticum carthamoides. Phytoecdysteroids, in particular – beta-ecdysterone, in the form of polyhydroxysterol, in the human body provides one of the main effects of the anabolic steroids – increased synthesis of bioproteins. The anabolic steroids have an influence on the nucleic metabolism as they control the transcription from DNA to mRNA and this is how they stimulate the production of different bioproteins (structural, enzymatic etc.) which are providing the adaptation of the human organism to the higher volume of physical activity, including increase of muscle mass, power and endurance. Beta-ecdysterone does not increase the transcription of DNA to mRNA but it speeds up the synthesis of bioproteins in the already available mRNA. This leads to increased protein synthesis, respectively to positive nitrogen balance, which is compulsory for muscle growth. The ecdysterone has an influence on the energy metabolism – first it stimulates the synthesis of glycogen in the muscles and the liver and second – increases the recovery of ATP in the muscle cells, which is needed for muscle contractions. This leads to the quicker recovery of glycogen reserves after a workout and more power and endurance during it, respectively – a more productive workout. Beta-ecdysterone stimulates the synthesis of a few key enzymes the normal function of the central nervous system as it prevents functional disorder of the nervous system, which may occur during high intensive workouts. Beta-ecdysterone is a key food supplement, which in dose 10mg/kg of body weight provides complex, similar to the anabolic steroids effect but without their side effects. Through acceleration of the protein synthesis and energy metabolism directly stimulates the muscle growth, increases the muscle power and the endurance. It has favorable effect on the lipid exchange and with proper nutrition plan it can speed up the reduction of body fats while at the same time protects the muscles from disintegration. It also has a positive effect over the functions of the central nervous system as it increases the focus and motivation during a workout while protecting from depression which can occur after a heavy workout. It is recommended for muscle building programs as well as for weight loss programs with maximum protection of the skeletal musculature.