[6][7] A study in 2017 has shown that in subjects with 21-hydroxylase deficiency, serum 11β-OHP concentrations range from 0.012 to 3.37 ng/mL, while in control group it was below detection limit of 0.012 ng/mL.

[10] In the 2017 study mentioned above, serum progesterone concentrations in boys (10 days to 18 years old) with 21-hydroxylase deficiency reached levels similar to female luteal values (up to 10.14 ng/mL, depending on severity and treatment), while in the control group of boys progesterone was 0.07 ng/mL (0.22 nmol/L) on average, ranged from 0.05 to 0.40 ng/mL.

[8] In a 2016 study, classical CAH patients receiving glucocorticoid therapy had C19 11-oxygenated steroid serum levels that were elevated 3-4 fold compared to healthy controls.

[13][14] In males with CAH, 11-oxygenated androgen levels may indicate the presence testicular adrenal rest tumors.

[14][15][16] While studies suggest that 11β-OHP, also known as 21-deoxycorticosterone, can be used as marker for adrenal 21-hydroxylase deficiency,[6] another 21-carbon steroid — 21-deoxycortisol (produced from 17α-hydroxyprogesterone) gained acceptance for this purpose.