what are the reference ranges and ratios for testosterone lab tests

Reference Ranges and Ratios for Testosterone Lab Tests

Free Testosterone Ratio

Dr. Peter Attia recommends that the ideal level of free testosterone in males should be about 2% of one's total testosterone. Kyle Gillett corroborates this, stating that the reference range typically spans from 1% to 4%. Variations can occur due to genetic factors or conditions like varicose veins in the testes, which can affect SHBG (Sex Hormone Binding Globulin) levels and, consequently, the free testosterone ratio 1.

SHBG and Testosterone

SHBG plays a crucial role in the availability of free testosterone. High levels of SHBG can bind to testosterone, limiting the amount of free testosterone available to affect cells. Supplements like boron may help lower SHBG, potentially improving the ratio of free to total testosterone 1.

Practical Steps

1. Aim for about 2% free testosterone as a rule of thumb but note that 1%-4% is within the typical range.
2. Consider SHBG levels when interpreting results, as high SHBG can reduce free testosterone.
3. Address any symptoms or conditions that might affect these ratios, such as varicocele (varicose veins in the testes).

These guidelines can help in understanding and optimizing testosterone levels through lab tests.