500ius will raise endogenous testosterone, so will 250ius and so will 125ius.

It all depends on responsive the testes are. Thats the question at hand here, not the AMOUNT of HCG needed. If your testes are online and firing (off cycle) a small amount of HCG will spike testosterone by stimulating the leydig's directly.

If you have left them dormant and are suffering from testicular dysfunction a small amount may not do squat.

Larger initial doses are required if the testes have NOT been stimulated on cycle and testicular dysfunction has begin to set it.