
Originally Posted by
Youthful55guy
First off, I have to say up front that I have no experience with low SHBG and I've not done a lot of research into the literature. This is because I have the opposite problem of producing way too much SHBG and most of my research and experimentation has been with finding ways to deal with it being high.
I would not phrase it quite like you did, SHBG has nothing (that I know of) to do with receptor activity. What it does do is bind sex hormones and it has a particularly high affinity for androgens (like T and DHT). So this means with high SHBG, less of the androgens are available to bind to the receptors to stimulate the receptors to do their thing. Also, SHBG bound T will not pass through the blood-brain barrier, so while you may have sufficient Total T in the blood, your brain is starved of the hormone because SHBG won't let it through.
With low SHBG, more of the androgens (T, DHT, or whatever synthetic androgens you are taking) is available to bind and stimulate receptors. However, while higher free T/androgens is good, it also means that it will be metabolized by the liver and excreted much faster. That is why guys with low SHBG end up taking higher does of androgens to get the same effect, because they don't have sufficient SHBG to protect the androgens from liver metabolism. In this respect SHBG serves as a buffer for the androgens.
Bottom line is that both high and low SHBG is not a good thing but for different reasons. The bad news is that low SHBG is more difficult to treat. With high SHBG, you simply have to increase the dose so that you saturate the protein and enough of it spills over to the free form of the androgen to make you feel normal again (or build muscle if that's your goal). Also, as Kel mentioned, certain higher androgens in general suppress SHBG production and certain synthetic androgens will greatly suppress it, even at very low doses (e.g., Winstrol and Anavar). I do not know if nandrolone has this same effect.
With low SHBG, there's not a lot you can do (that I know of) to beef up production of the protein. I've read of some guys having success with more frequent daily injections rather than weekly or even twice weekly injections. This will help to keep some active T in your body at all times and avoid the roller coaster of big injections and rapid metabolism by the liver.