Tetrahydrocortisol, Urine Creatinine Ratio Unit Converter

Tetrahydrocortisol (THF) is one of the major breakdown products of cortisol, the body's primary stress hormone. When cortisol is metabolized in the liver, enzymes called 5-beta-reductase and 3-alpha-hydroxysteroid dehydrogenase convert it into tetrahydrocortisol, which is then excreted in the urine.

The urine creatinine ratio divides tetrahydrocortisol by creatinine (a waste product excreted at a fairly constant rate) to correct for how dilute or concentrated the urine sample is. This provides a more reliable measure of cortisol metabolism than raw urinary THF alone.

Tetrahydrocortisol is commonly measured alongside its isomer allo-tetrahydrocortisol (5a-THF) and tetrahydrocortisone (THE) as part of a comprehensive urinary steroid profile. Together, these metabolites account for the majority of cortisol cleared from the body and provide a window into both cortisol production and the efficiency of cortisol metabolism.

Tetrahydrocortisol is produced in the liver when cortisol (made by the adrenal glands) is broken down by 5-beta-reductase and then further reduced by 3-alpha-hydroxysteroid dehydrogenase. It is conjugated with glucuronic acid and excreted by the kidneys into the urine.