Here is a study i just found done on obese and non obese women that found better biovavailability in both groups of women when hCG was injected IM. In obese women the bioavailability of hCG was even more pronounced when they injected IM as opposed to SQ. One would assume that these findings would also apply to men.
http://humrep.oxfordjournals.org/con...8/11/2294.full
There is another study that I remember reading several years ago which also found better bioavailability when hCG was injected IM but I will need more time to search for it.
Here is a post from Dr Romeo Mariano (Marianco on Meso-rx) back in 2007 which I think sums it up for us:
"I think both IM and SQ injections are both valid routes.
For fertility protocols, both are equivalent, for example.
IM injections will give you a faster response since muscle has many more blood vessels than subcutaneous fat. The higher peak levels of HCG can then stimulate a higher peak testosterone and estradiol production which in some people gives them a better sense of well-being - however transient that may be depending on the half-life of testosterone and estradiol in that particular person, and the other hormone influences of testosterone and estradiol.
A SQ injection will give you a smaller peak of HCG in the blood but a longer duration of action. This may be useful then when one wants to reduce testicular atrophy by using intermittent HCG injections, rather than daily HCG injections.
It may be worthwhile to try both routes to see what one prefers."