TL:DR SHBG is an oft-overlooked and poorly understood blood marker. Low (and high) SHBG is correlated with health issues, and I speculate that HCG use will maintain SHBG at normal levels in a SARM only cycle.

SHBG (sex hormone-binding globulin) is a glycoprotein (protein with a carbohydrate attached) that binds to androgen and estrogen. SHBG helps circulate these compounds through your bloodstream. Or put another way, SHBG controls the amount of testosterone that your bodies can use. Its production is Influenced by genetics, metabolic or hormonal factors. High levels can be due to hepatitis, hyperthyroidism, HIV or some medicines. Low levels of SHBG are related with obesity, type 2 diabetes, hypothyroidism, or excess growth hormone. Diet can also play a role.

Or, as is the reason that we are looking at it, SARM use. Ostarine suppresses SHBG 31% more than 600mg of Test E. We also know that SARMs lower total testosterone, with a more limited effect on free testosterone. SHBG is created by the liver and introduced into the bloodstream. Androgen receptor agonists, (SARMs, Testosterone and other AAS) will reliably lower SHBG, demonstrated in this study, while anti-androgens increase SHBG. (Cheers for this study, /u/MezDez)

OK, SARMs lower SHBG, so what? There is no immediate health risk of low SHBG as far as I can tell, though there is an association between low SHBG and high blood pressure. And high LDL (the bad cholesterol). The implication is if you are able to maintain SHBG at normal levels, common side effects may be mitigated.

In my last article, I proposed that one of the actions through which hair loss could happen is by the lower SHBG, which leaves DHT unbound. And if you’re predisposed to hair loss, DHT is what will trigger inflammation and follicle death. About 55% of all testosterone is bound to SHBG.

HCG kept SHBG at normal levels in TRT. This may open a potential avenue of HCG use for those that do not wish to pin test, but are willing to subq an alternative that will also help maintain test levels while on SARM only cycle. This is an interesting avenue for us to explore in the coming weeks, as it would theoretically mitigate hair loss side effects and keep blood pressure within range.