HCG is a natural analog of LH, the pituitary-produced hormone which stimulates sex hormone production in the testes or ovaries. HCG binds and activates the same receptor as LH and is equally effective in stimulating testosterone production in men, or estrogen production in females.
This LH analog exists because it provides additional functions required in pregnancy which LH cannot support. These additional functions cannot occur in men and have no practical effect or consequence with regard to using HCG for improved testicular function, and so are omitted here.
Pharmaceutical HCG
HCG is typically isolated from the urine of pregnant women: the pharmaceutical process of course involves extensive purification. Despite this esoteric sourcing I know of no quality problems with any genuine pharmaceutical brands of HCG.
All or nearly all practical experience in bodybuilding is with this HCG type, which is generally sold in vials of lyophilized powder, typically at 5000 or 10,000 IU per vial.
HCG may also be produced by recombinant DNA technology, similar to modern hGH production. The Ovidrel brand is manufactured this way, and is available only in preloaded syringes.
Availability of recombinant HCG at best low at present and there is no performance advantage to be experienced from choosing this type.
A technical difference, which makes no difference for bodybuilding, exists between these types of HCG. Namely, recombinant HCG consists only of dimeric HCG with two types of subunits. In contrast, urine-sourced HCG, as with HCG found in the bloodstream during pregnancy, also includes the subunits themselves as monomers. Since it’s possible that with chronic use this could have an outcome difference, that aspect will be discussed, but later on.
HCG Dosing For Stimulation Of Testosterone Production
Medical dosing of HCG has traditionally been 5000 IU per injection. Prior to 1998, bodybuilding use for restoration of testicular function was the same. As a result, as this is extreme overdose, it was widely considered to be a harsh drug.
At that time, I introduced lower dosing of no more than 1500 IU per injection, and more preferably no more than 1000 IU, with example recommended usage being 500 IU 3x/week.
Since then my recommendation for maximum injection amount has dropped to 500 IU, because no added benefit has been found to using more than this at a time, provided that injections are reasonably frequent.
The recommended weekly dosing range is from about 700 to 1750 IU. Example dosings are 100-250 IU daily, or 200-500 IU every other day, or 250-500 IU three times per week.
In addition to such dosings being followed by a very large number of individuals over many years with excellent success, scientific study has since validated these dosings. As measured by intratesticular testosterone levels, this dosing level maximizes results. There is simply no point to more.
Multiple injections per week are recommended because the half-life of HCG is only about 36 hours. Less frequent injections result in poor maintenance of blood levels.
