Study of the Effectiveness of Treatment of Sarcopenia With the Use of a Medicinal Product (Nandrolone), Comprehensive Physiotherapy and Diet

Inclusion Criteria: 1. individuals aged 60 years or older through 99 years of age. 2. Patients meeting the following criteria diagnosed with sarcopenia based on EWGSOP 2 criteria from 2019: * weakness of muscle strength measured by hand dynamometer ( \< 27 kg for men and 16 kg for women) and * reduction in densitometry: * upper and lower limb muscle mass (ASMM)(below 7.0 kg/m2 height in men and 5.5 kg/m2 in women) or * total muscle mass of the arms and legs in men less than 20 kg and less than 15 kg in women). Exclusion Criteria: 1. Mini-Mental State Examination (MMSE) score less than 24; 2. malignant neoplasm, lymphoproliferative or myeloproliferative disorders requiring oncologic or palliative treatment and the period before: 5 years in the case of: malignant melanoma, leukemia, Hodgkin's disease, malignant lymphomas, kidney tumors, 12 months in the case of other malignant neoplasms after the completion of surgery, chemotherapy or radiotherapy; 3. history of oncologic diagnosis of focal lesions in the prostate gland; 4. acute and chronic inflammatory diseases of the gastrointestinal tract that present with malabsorption (celiac disease, ulcerative colitis, Crohn's disease, etc.); 5. uncompensated hyper- or hypothyroidism; 6. recent history of myocardial infarction or stroke (up to 4 weeks prior to study entry); history of thromboembolism (up to 6 months prior to study entry) or recurrent thromboembolism; 7. poorly controlled hypertension; 8. liver impairment (AST and/or ALT \> 3x normal: AST\> 111 U/l and ALT\> 123 U/l); 9 Acute kidney injury and/or chronic kidney disease (stage G4 and G5); 10\. nephrotic syndrome, acute or chronic glomerulonephritis; 11. advanced circulatory failure (NYHA stages III and IV); 12. Acute and chronic respiratory failure requiring oxygen therapy; 13. Amyotrophic lateral sclerosis, multiple sclerosis, myasthenia gravis, dystrophies, spinal muscular atrophy type IV, primary muscular disorders (ICD-10 G71), toxic-field myopathies, myopathies in the course of infectious and parasitic diseases. Epilepsy; 14. need for treatment during the study period: * systemic corticosteroids for more than 3 weeks at a dose equivalent to greater than or equal to 5 mg prednisone; * hormone replacement therapy, * 5-alpha reductase inhibitors, * aromatase inhibitors, * anti-estrogenic hormonal drugs with anabolic effects other than nandrolone decanoate, * megestrol. 15. Lack of informed consent for participation in the study.