No subjects enrolled

This study will be the first demonstration of the utility and feasibility of Phosphodiesterase Type 5 inhibitor as an effective pharmacological therapy for improving anabolic resistant states.

Inclusion Criteria:

• Ages 60-75 yrs
• Recently prescribed 5mg of tadalafil daily for clinical purposes

Exclusion Criteria:

• History of diabetes

• history of hypotension including orthostatic hypotension

• History of malignancy or chemo/radiation therapy in the 6 months prior to enrollment

• History of short gut syndrome, gastrointestinal bypass/reduction surgery (Lap band, gastric sleeve, etc.)

• Subjects who cannot refrain from using protein or amino acid supplements for 7 days prior to Visit 2 and 3.

• Alcohol consumption of ≥ 5 units/servings per day

• Concomitant use of

  • oral or injectable corticosteroids
  • testosterone, insulin like growth factor-1, or similar anabolic agent
  • riociguat (Adempas)
  • nitroglycerin
  • isosorbide dinitrate (Isordil)
  • isosorbide mononitrate (Imdur, Monoket)
  • doxazosin (Cardura)
  • prazosin (Minipress)
  • terazosin (Hytrin)

• Any other disease or condition that would place the subject at increased risk of harm if they were to participate, at the discretion of the study physician

Males 60-75 years who have been prescribed 5mg daily tadalafil by their physician.