Testosterone, Free (Dialysis), Total (MS) and Sex Hormone Binding Globulin

This panel measures three related things in your blood: your total testosterone level (using a very precise laboratory technique called mass spectrometry), your 'free' testosterone (the active portion not attached to proteins), and a protein called SHBG that carries testosterone through your bloodstream. Most testosterone in your blood is bound to SHBG and cannot act on your body's tissues—only the free portion is immediately active. By measuring all three together, your doctor gets a complete picture of how much testosterone is actually available to your body, which is more informative than measuring total testosterone alone. This panel helps evaluate symptoms like low energy, changes in sex drive, fertility concerns, or signs of too much or too little testosterone. Results are interpreted alongside your symptoms, medical history, and other test results.

When elevated: Elevated total and/or free testosterone may indicate androgen excess states such as polycystic ovary syndrome (PCOS) in women, congenital adrenal hyperplasia, androgen-secreting tumors (adrenal or gonadal), exogenous androgen use, or anabolic steroid administration. High SHBG with normal total testosterone may result in low-normal free testosterone, potentially causing symptoms of androgen deficiency despite seemingly adequate total levels. Elevated free testosterone with normal or low total testosterone suggests reduced SHBG, increasing androgen bioavailability. When low: Low total and/or free testosterone is consistent with hypogonadism, which may be primary (testicular or ovarian failure) or secondary (hypothalamic-pituitary dysfunction). In men, low testosterone is associated with symptoms including decreased libido, erectile dysfunction, fatigue, reduced muscle mass, and osteoporosis. Low SHBG increases the free fraction relative to total testosterone, which may mask androgen deficiency on total testosterone measurement alone; conversely, high SHBG with low-normal total testosterone can produce clinically significant androgen deficiency.

Free and total testosterone drive muscle protein synthesis, strength gains, and recovery from training stress in both male and female athletes. This comprehensive panel reveals true androgen bioavailability—critical when intense training, body composition changes, or supplements alter SHBG levels and can mask meaningful shifts in hormonal status that affect performance and adaptation.