Serms raise my SHBG but i dont notice any difference when its 15 versus 18. The estrogenic half of a SERM drug sure can elevate SHBG.
I dont think someone with genetically low SHBG can do anything to raise that.
...but, from a laboratory testing standpoint, 15 and 18 really are the same thing.
It won't where SHBG expression is genetically deficient, as Oldbull posits. If the liver doesn't respond properly to estradiol, it won't respond any better to a weak, tissue specific estrogen agonist like the clomiphene isomer zuclomiphene.
Moreover, the claim that clomiphene (assuming that this is the referenced SERM) increases estradiol is contentious. In the oft referenced study where clomiphene "increases" SHBG from an average of 38 to 54 nmol/L, the careful reader notes that the researchers conclude that the SHBG increase was probably due to the concomitant increase in serum estradiol, and not to a more direct action of clomiphene. In this same study, E2 increased from ~24 to ~43 pg/mL, for example.
There is a more promising compound being studied. It's a selective estrogen receptor agonist with a 10-fold preference for activation of ERα relative to ERβ. This can send SHBG into the stratosphere in eugonadal men, and therefore I suspect it may hold promise, in small doses, for those men who suffer from SHBG not being naturally expressed in adequate proportion to their hormones.
Any thought given to revealing the antioxidant regimen that tripled your SHBG output? I still believe you've just gummed up your liver with too many supplements, but if you've actually managed to accidentally overstimulate SHBG to an unheard of degree, it's worth breaking apart the regimen to find the components responsible.