This is a prospective, randomized controlled trial to evaluate the ability of hydrogen peroxide preparation in addition to chlorhexidine to decrease the colonization of Propionibacterium acnes(a bacteria commonly found in the dermis of the skin surrounding the shoulder in order to decrease postoperative joint infection.

Inclusion Criteria:

1. All male patients (>18) undergoing shoulder arthroscopy

Exclusion Criteria:

1. Female patients

2. Patients with active acne

3. Patients who have taken antibiotics within a month of their surgery

4. Subjects allergic to any of the following agents:

   o Benzoyl peroxide

5. Subjects with psoriatic/eczematous lesions on the shoulder girdle.