Fibrous capsule formation around implants remains a difficult problem in plastic surgery. The etiology is elusive but the end result is an exaggerated deposition of dense collagen in the capsules surrounding the implants. The purpose of this study was to determine if halofuginone(HF), a collagen type I inhibitor, would reduce the fibrous reaction surrounding a silasitic disk in a rat model. Therefore HF by reducing the collagen content within the capsule could potentially decrease the incidence of capsular contracture in breast augmentation. Silastic disks (6x2mm) were implanted subcutaneously into the dorsum of 19 adult male Sprague-Dawley rats. The rats were divided into four groups and received HF in their feed at different time periods over the eight week study. Implants were removed and the capsules examined. Colorimetric analysis quantified collagen index(content) and was compared between the groups. Blood samples were taken and HF was measured by high performance liquid chromatography. Our findings indicate that HF is effective at inhibiting collagen deposition. Its ability to inhibit collagen deposition in new and pre-existing fibrous capsules suggests that it may be a useful adjunct to minimize the formation of capsules around implants.