I am not sure about the supplement in itself, but I know that with an increase in testosterone your body may aromatize it into Estrogen (many times seen in Testosterone Replacement Therapy). I’ve just never heard of a supplement actually being very efficient at increasing testosterone unless there was a deficiency in something necessary, like Zinc.
When a man’s Estrogen increases in TRT they take what’s known as an Aromatase Inhibitor (“AI”) to help curb the increase in Estrogen and keep it within optimal serum range. But this, too, is a pharmaceutical that is given by medical professionals. Although it is said that Grapeseed Extract may be beneficial in this capacity, I’ve also heard that there isn’t profound, solid evidence thereof.
Honestly, I’d see a doctor and get a whole slew of bloodwork done that is generally done for TRT: Free T, Total T, Estradiol, FSH, LH, SHBG, Hematocrit, etc. Get a baseline and show them the supplement.