Implants are sterile small tablets meant for insertion under the skin by making a small incision beneath the skin, which is stitched later. Implants are about 3.2 mm in diameter and 8 mm in length and prepared by compression. They are implanted subcutaneously for the purpose of providing slow and continuous release of medication over a prolonged period of time. Steroidal hormones such as testosterone and stilbestrol are formulated as implants.