HCG acts just like LH in the body; so it does a lot of really good things for you when you're shut down. You need your testes to function and HCG does just that; it also helps produce more natural Test as well
Small doses done frequently is best. Dosages vary but generally common is 250 iu per injection. Really shouldn't inject anything over 350 iu as it can desensitize the leydig cells on the Testes and increase intra-testicle E2 (not a good thing).
Bass, can get away with what he's doing but he'd be better served splitting that 500 into two 250.