Testsosterone implants contain 800 mg of testosterone (usually in the form of four 200 mg pellets). They are implanted into the buttocks or abdomen, and provide testosterone replacement for around six months. Implants are replaced periodically, once symptoms of testosterone deficiency recur. Inserting the testosterone pellets is a minor surgical procedure, requiring local anaesthetic ; this is the major limitation of this method of treatment. However, men using this form of testosterone replacement are usually satisfied with the method, and are more likely to continue being treated than men using other modes of testosterone replacement.