Free androgen index (FAI)
The Free Androgen Index is a calculated ratio that estimates how much testosterone is available to act in the body relative to the binding protein SHBG (sex hormone–binding globulin). It is computed as 100 × total testosterone (nmol/L) ÷ SHBG (nmol/L) and is primarily used in women to approximate bioavailable androgen activity when direct free testosterone measurement is not available.
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Total prostate-specific antigen (PSA)
Total prostate-specific antigen (PSA) is a protein produced by the prostate gland. It is a commonly measured marker that provides insight into prostate wellness. Elevated PSA levels may indicate prostate problems, but can also be caused by age, prostatitis, or recent procedures.
Free prostate-specific antigen (PSA)
Free PSA is the unbound form of prostate-specific antigen that circulates independently in blood. The free-to-total PSA ratio provides additional context for understanding prostate wellness. Higher free PSA percentages are generally associated with benign conditions.
Luteinizing hormone (LH)
Luteinizing hormone (LH) is produced by the pituitary gland and plays a crucial role in reproductive function. In women, it triggers ovulation and stimulates progesterone production. In men, it stimulates testosterone production. LH levels help evaluate fertility, menopause, and pituitary disorders.
Follicle-stimulating hormone (FSH)
Follicle-stimulating hormone (FSH) is produced by the pituitary gland and regulates reproductive processes. In women, it stimulates ovarian follicle development and estrogen production. In men, it supports sperm production. FSH levels help assess fertility, menopause, and reproductive disorders.
Estradiol
Estradiol is the most potent form of estrogen, primarily produced by the ovaries in women and in smaller amounts by men. It regulates menstrual cycles, supports bone health, and affects cardiovascular function. Estradiol levels help assess reproductive health, menopause, and hormone-related disorders.
Sex hormone-binding protein (SHBG)
Sex hormone-binding globulin (SHBG) is a protein that binds and transports sex hormones (testosterone and estradiol) in the blood. It regulates the amount of free, active hormones available to tissues. SHBG levels help evaluate hormone balance and can be affected by age, obesity, and liver function.