Inclusion Criteria:  Adult patients who undergo primary Total Shoulder Arthroplasty or Reverse Total Shoulder Arthroplasty Patient willing and able to complete postoperative surveys Post-Menopausal Women and Men over the age of 55  Exclusion Criteria:  Patients reporting caffeine consumption in excess of 300mg daily Patient has known history of opioid addiction, has taken opioids preoperatively, or other forms of substance abuse. Patient has history of cardiac diseases that might be aggravated by the use of caffeine, as diagnosed by a cardiologist or demonstrated by an abnormal EKG. Patient has a known allergy to aspirin or caffeine. Patient has history of cancer, neuropathic pain, or nerve degenerative disease that would affect patient reported outcomes including pain. Patient has history of anxiety disorder Patients with known sleep disturbances that would otherwise be affected by caffeine Patients undergoing revision surgery Patients who require alternate DVT prophylaxis other than ASA. Patients undergoing inpatient arthroplasty Workman's comp patient or patient has current litigation pending