HCG: HCG causes stimulation to restore the function of the inactive testes . It's excessive stimulation can cause the testicles to rapidly return to their normal size. While HCG offers no the female no performance enhancing ability, it does prove very useful to the male steroid user. The obvious use of course being to stimulate the production of endogeneous testosterone. The activity of HCG in the male body is due to its ability to mimic LH (lutinizing hormone), a pituitary hormone that stimulates Leydig's cell in the testes to manufacture testosterone. Restoring endogenous testosterone production is a special concern at the end of each steroid cycle. A time when a subnormal androgen level could be costly. The main concern is the action of cortisol. Cortisol sends the opposite message to the muscles than testosterone, or to breakdown protein in the cell. Left unchecked in the body, cortisol can quickly strip much of your new muscle mass away. The main focus with HCG is to restore the normal ability of the testes to respond to endogenous luteinzing hormone. The longer the period of inactivity , the ability to restore is seriously reduced. In such a state testosterone levels may not reach a normal point. Many who have suffered severe testicular shrinkage may be able to relate. The excessive stimulation taking HCG can cause can return the testicles rapidly to their normal size and function. Estrogen production is also raised with the use of HCG. Dosage: The usual protocol is to inject 1500-300 I.U. every 4th or 5th day. For a duration of usually no longer than 2 or 3 weeks. If used for too long or at too high a dose, the drug may actually function to desensitise the Leydig's cells to luteinizing hormone. Further hindering a return to homeostasis. Timing the initial dose is very crucial.