The use of Metanabolu forces c17-alpha-alkylation. This structure protects the active chemical agent against deactivation in human liver. This allows the active ingredient fully penetrate into the bloodstream. Long use c17-alpha-alkylated powodowuje liver damage (hepatitis, hepatic purpura, liver cancer, and gastrointestinal tract) as well as contribute to the development of tumors. It is therefore necessary testing liver function before, during and after the cycle. The cycle should be short, up to 8 weeks to avoid possible damage to the liver. Many destinations the next cycle, it is necessary zregenerownie liver generally available on the market means. It is recommended to use drugs such as liver protectants. Hepatil or otherwise available in pharmacies without a prescription means.