This clinical trial aims to find out whether AMC6156 can improve physical function and is safe in older adults with sarcopenia. Participants will take AMC6156 or a placebo daily for 12 weeks, and their movement, strength, and safety will be regularly monitored through tests and checkups.

Inclusion Criteria:

• Voluntary participation with written informed consent
• Male ≥ 65 years or postmenopausal female
• Diagnosed with sarcopenia:
• ASM < 7.0 kg/m² (men) or < 5.4 kg/m² (women)
• Plus low handgrip strength or SPPB ≤ 9
• MNA screening score ≥ 8
• Body weight ≥ 35 kg, BMI between 15-30 kg/m²
• Willing and able to follow exercise and nutrition guidance

Exclusion Criteria:

• Allergy to investigational drug
• History of GI bleeding, ulcers, or severe liver/kidney/heart disease
• QTc ≥ 450 ms with symptoms
• Severe COPD, uncontrolled diabetes or thyroid disease
• Diseases causing cachexia or muscle wasting (e.g., ALS, Parkinson's)
• Vitamin D deficiency (<10 ng/mL), hemoglobin <10 g/dL
• Severe psychiatric disorders or MMSE < 21
• Inability to walk or recent fracture/surgery affecting mobility
• Use of prohibited medications or recent participation in other clinical trials
• Investigator deems the subject unsuitable for the study