Inclusion Criteria:

• 1. Left ventricular ejection fraction (LVEF) ≤40%, New York Heart Association (NHYA) class II to IV symptoms or N-terminal pro B-natriuretic peptide (NT-proBNP) \>300 pg/mL
• 2. Age 18 years to 100 years, inclusive
• 3. Receiving guideline-directed medical therapy (GDMT), unless contraindicated or not tolerated
• 4. Any of the following markers of severe HF within prior 12 months: i) Inotropic therapy; ii) 1 or more HF hospitalizations; iii) LVEF ≤25%; iv) Peak oxygen consumption (VO2) \<50% predicted or ≤16 mL/kg/min; v) 6-minute walk distance \<300 meters; vi) Unintentional weight loss \>5% of bodyweight over the past year; vii) Moderate or severe muscle wasting on physical examination

Exclusion Criteria:

• 1. Pregnancy, planning to become pregnant, or women of reproductive potential unwilling to complete pre-DXA urine pregnancy test before first DXA or randomization
• 2. History of left ventricular assist device (LVAD), heart transplantation, or estimated glomerular filtration rate (eGFR) \<20 mL/min/1.73 m2
• 3. An identified clinical disorder associated with skeletal muscle weakness/wasting (e.g., muscular dystrophy, mitochondrial disorder, active cancer, modified Rankin score greater or equal to 4 post-stroke)
• 4. Milk allergy, protein allergy, lactose intolerance, and galactosemia
• 5. Weight ≥350 pounds and/or BMI ≥40 kg/m2