Andrew Huberman· PhD
So people talk about that the level of free testosterone is really what's important and that you want to optimize free testosterone, that's a little bit of a tricky statement, that's kind of like, it's true, and yet, it's not really reflective of a thorough understanding of how these binding globulins work, remember, these binding globulins aren't there to soak up all your testosterone just to make it hard for you to free up testosterone and you know, make gains in the gym or whatever it is, or have increases in libido, they're there to actually transport testosterone to specific tissues, to shuttle them to specific tissues and to set the rate of bound and unbound testosterone so that's it's not all unbound at once, and you know, it's always interesting to look in the literature and see how everyone wants to free up their testosterone so that it can work, but sex hormone binding globulin can bind up too much testosterone to the point where it's having negative effects on libido or on muscle growth and fat loss and things of that sort, this is true in males and females, or it can be doing exactly what it's supposed to do, which is shuttling testosterone to the proper tissues and organs where it has all these effects, including the brain.