An extract of a part of a Solidago species, wherein said part has grown above the earth, or the solid residue remaining after the removal of the solvent content of the extract as the active ingredient is used for the regeneration of the organism of a mammal after long-lasting immobilization, anorexia, states following a disease or accompanied by weight loss as well as for muscle development or muscle growth during muscle developing training, treatment of muscular strain and adaptation to high-altitude as well as for the prevention or treatment of neurodegenerative diseases and/or motility disorders of the gastrointestinal system.