Testosterone boosting regiments usually focus on maximizing free T by lowering SHBG but this may be a contradictory approach. Instead of taking testosterone out of action, sex hormone binding globulin actually makes testosterone more useful and more active.
Refer to this study: Sex Hormone Binding Globulin Modifies Testosterone Action and Metabolism in Prostate Cancer Cells
When they conducted sex hormone binding globulin tests, they found that SHBG actually increases the testosterone in your body. Because if you have a low SHBG level, your body picks up and metabolizes your testosterone too quickly by your cells.
"IN THE PRESENCE OF SHBG, THERE IS REDUCED TESTOSTERONE UPTAKE BY THE CELLS, BUT, DISPOSAL AND INACTIVATION OF TESTOSTERONE IS REDUCED…THE EFFECTS OF TESTOSTERONE ON ANDROGEN IS INCREASED."
Clinically, estrogen receptor antagonists (Tamoxifen, Clomid) stimulate SHBG. While estrogen receptor agonists (Tibolone) cause a downregulation in SHBG.
Low SHBG may be a sign of chronic disease such as obesity, low insulin levels, cardiovascular disease, diabetes, metabolic syndrome, apnea, inflammation, hypothyroidism and elevated triglycerides.
Substances such as caffeine and creatine increase SHBG.
SHBG will increase in men as testosterone levels fall over time. Maybe the body just tries to compensate the low T with sex hormone binding globulin to make testosterone more active?
TLDR:
Refer to this study: Sex Hormone Binding Globulin Modifies Testosterone Action and Metabolism in Prostate Cancer Cells
When they conducted sex hormone binding globulin tests, they found that SHBG actually increases the testosterone in your body. Because if you have a low SHBG level, your body picks up and metabolizes your testosterone too quickly by your cells.
"IN THE PRESENCE OF SHBG, THERE IS REDUCED TESTOSTERONE UPTAKE BY THE CELLS, BUT, DISPOSAL AND INACTIVATION OF TESTOSTERONE IS REDUCED…THE EFFECTS OF TESTOSTERONE ON ANDROGEN IS INCREASED."
Clinically, estrogen receptor antagonists (Tamoxifen, Clomid) stimulate SHBG. While estrogen receptor agonists (Tibolone) cause a downregulation in SHBG.
Low SHBG may be a sign of chronic disease such as obesity, low insulin levels, cardiovascular disease, diabetes, metabolic syndrome, apnea, inflammation, hypothyroidism and elevated triglycerides.
Substances such as caffeine and creatine increase SHBG.
SHBG will increase in men as testosterone levels fall over time. Maybe the body just tries to compensate the low T with sex hormone binding globulin to make testosterone more active?
TLDR:
- Total testosterone counts, while free testosterone is meaningless
- SHBG levels should be high, not low