2-Hydroxyestradiol, Urine Creatinine Ratio Unit Converter

2-Hydroxyestradiol (2-OH-E2) is a metabolite of estradiol, the body's most potent estrogen. It is produced when estradiol undergoes Phase I hydroxylation at the C-2 position, primarily in the liver. This is the major metabolic pathway for estradiol breakdown.

This marker measures 2-OH-E2 in a urine sample, divided by urinary creatinine concentration to correct for urine dilution. The ratio approximates what a full 24-hour urine collection would show from a single convenient spot sample.

2-OH-E2 is classified as a catechol estrogen and has roughly 7-11% of the estrogen receptor binding affinity of its parent hormone estradiol. It is considered part of the "protective" 2-hydroxylation pathway of estrogen metabolism, in contrast to the potentially harmful 4-hydroxylation pathway.

2-OH-E2 is formed from estradiol through hydroxylation catalyzed by CYP1A2 and CYP3A4 enzymes, primarily in the liver. Smaller amounts are produced in the uterus, breast, kidney, brain, and pituitary gland via CYP1A1 and CYP3A4.