11-Deoxycortisol Unit Converter
11-Deoxycortisol Unit Converter
Convert 11-deoxycortisol between ng/dL, nmol/L, ng/mL and µg/L — the steroid one enzyme short of cortisol, which accumulates in 11β-hydroxylase deficiency and is the thing the metyrapone test actually measures. The conversion is simple; the reference intervals and the metyrapone thresholds are where published sources stop agreeing.
11-Deoxycortisol converter
Mass ⇄ molar11-deoxycortisol 40 ng/dL in an adult, basal sample
The conversion, derived from the molecular weight
ng/dL = nmol/L ÷ 0.028863
because 1 ng/dL is 10⁻⁸ g/L, and 10⁻⁸ ÷ 346.47 g/mol = 2.88625 × 10⁻¹¹ mol/L = 0.0288625 nmol/L
- MW 346.47
- 11-deoxycortisol (cortexolone, compound S), C₂₁H₃₀O₄ — cortisol without the 11β-hydroxyl. One hydroxylation short of the finished hormone
- ng/dL → nmol/L is ÷ 34.6
- a workable mental check: divide the ng/dL figure by about 35. 40 ng/dL is 1.15 nmol/L, and 7000 ng/dL is 202 nmol/L
- ng/mL = µg/L = ng/dL ÷ 100
- the usual hundred-fold trap. North American laboratories report this analyte in ng/dL and most of the rest of the world in nmol/L, so a bare number needs its unit before it means anything
- which assay
- both reference laboratories quoted on this page use mass spectrometry, and they still do not agree with each other. An immunoassay result is a third thing again. Compare a value only against the interval printed on its own report
Worked example
11-deoxycortisol 40 ng/dL in an adult, basal sample
40 × 0.028863 = 1.15 nmol/L (1.1545 before rounding)
40 ng/dL = 0.40 ng/mL = 0.40 µg/L — the hundred-fold step
That is inside Mayo's adult interval of 10–79 ng/dL (0.29–2.28 nmol/L), and outside ARUP's, which puts the adult male limit at <50 ng/dL and the female limit at <33 ng/dL
Now the number that matters. A normal pituitary response to overnight metyrapone is an 11-deoxycortisol above 200 nmol/L, which is 6,929 ng/dL — around 170 times this basal value. The test is read against that, not against the interval above
Two mass-spectrometry laboratories, two adult intervals
| Source | Method | Adult interval | Same in nmol/L |
|---|---|---|---|
| Mayo Clinic Laboratories, DCORT | LC-MS/MS | 10–79 ng/dL (over 18 years) | 0.29–2.28 |
| Mayo Clinic Laboratories, DCORT | LC-MS/MS | <344 ng/dL (18 years and under) | <9.93 |
| ARUP Laboratories, 0092331 | HPLC-MS/MS | <33 ng/dL (female, 18+) | <0.95 |
| ARUP Laboratories, 0092331 | HPLC-MS/MS | <50 ng/dL (male, 18+) | <1.44 |
| UK Supra-Regional Assay Service | Not stated | 7–18 nmol/L (unaffected adults, 09:00) | 243–624 ng/dL |
Metyrapone test thresholds, and what each one claims
| Source | Threshold | In nmol/L | What it claims |
|---|---|---|---|
| Mayo Clinic Laboratories, DCORT | <1,700 ng/dL at 8 hours | <49 | Probable adrenal insufficiency |
| ARUP Laboratories, 0092331 | >8,000 ng/dL post-stimulation | >231 | Expected response to stimulation |
| UK SAS, overnight metyrapone | >200 nmol/L | >200 | Normal pituitary response — valid only if cortisol fell below 200 nmol/L |
| Endocrine Connections 2026;15(8):e260261 | 197 nmol/L | 197 | Optimal cut-off, n=190, sensitivity 83%, specificity >90%, AUROC 0.907 |
Reading 11-deoxycortisol alongside the rest of the panel
| Pattern | Suggests |
|---|---|
| 11-deoxycortisol high, 17-OHP normal or mildly raised, androgens high, low renin hypertension | 11β-hydroxylase deficiency — the block is below 11-deoxycortisol, so it and deoxycorticosterone accumulate |
| 17-OHP markedly high, 11-deoxycortisol normal | 21-hydroxylase deficiency, the far commoner congenital adrenal hyperplasia — the block is one step earlier |
| 11-deoxycortisol high after metyrapone with cortisol suppressed | An intact hypothalamic-pituitary-adrenal axis — the intended result of the test |
| 11-deoxycortisol low after metyrapone with cortisol suppressed | Adrenal insufficiency, primary or secondary. The test does not separate the two |
| 11-deoxycortisol low after metyrapone with cortisol NOT suppressed | An uninterpretable test. The enzyme was not adequately blocked — check adherence and timing before concluding anything |
The last step before cortisol, and the test that stops it happening
11-deoxycortisol — cortexolone, or compound S in the older literature — is cortisol missing one hydroxyl group. The enzyme 11β-hydroxylase adds that group at carbon 11 and the molecule becomes cortisol. Everything interesting about the analyte follows from sitting immediately before that step. If the enzyme is congenitally deficient, 11-deoxycortisol accumulates behind the block, cortisol falls, ACTH rises in response, and the adrenal is driven harder into the pathway that is still open: the androgens. That produces the second commonest form of congenital adrenal hyperplasia, distinguished from 21-hydroxylase deficiency by where the pile-up sits and, clinically, by hypertension rather than salt wasting, because deoxycorticosterone accumulates alongside and has mineralocorticoid activity.
The same anatomy is what makes the metyrapone test work. Metyrapone inhibits 11β-hydroxylase pharmacologically, so it produces the deficiency on purpose for a few hours. Cortisol falls, the pituitary should notice and release ACTH, and the adrenal should respond by making a great deal of the substrate that can no longer be converted. So the test reads out as a high 11-deoxycortisol, and a failure to produce one means the axis could not respond. Two conditions have to be checked before the result means anything, and one of them is routinely skipped: the cortisol must actually have fallen, confirming the block was adequate, and the sample must be taken at the protocol’s interval, because the peak is transient. A metyrapone test with an unsuppressed cortisol is not a negative test, it is no test at all.
Which brings us to the numbers, where the sources stop agreeing. Mayo reports adults at 10 to 79 ng/dL by LC-MS/MS; ARUP, also by mass spectrometry, puts the adult female upper limit at 33 ng/dL and the male at 50. A factor of two between two reference laboratories running the same technology is unremarkable and is exactly why a value should be read against the interval printed on its own report. The UK Supra-Regional Assay Service, however, gives unaffected adults at 09:00 as 7 to 18 nmol/L, which is 243 to 624 ng/dL — above the top of both mass-spectrometry intervals by an order of magnitude. This page cannot reconcile that, so it shows it. The metyrapone thresholds have the same shape: ARUP’s 8,000 ng/dL, the SAS figure of 200 nmol/L and a 2026 series of 190 patients that derived 197 nmol/L by tandem mass spectrometry all land in the same place, while Mayo’s 1,700 ng/dL is four times lower — though Mayo’s is phrased as a floor below which insufficiency is probable rather than a ceiling above which the axis is intact, which is a different claim rather than a contradictory one.
The practical consequence is the same in both cases. Convert the units here, then read the converted number against the interval and the protocol your own laboratory publishes. This analyte is measured in small enough quantities, by enough different methods, and is used for enough different questions, that a threshold borrowed from another laboratory’s page is not a safe substitute for the one on your own.
Frequently asked questions
How do I convert 11-deoxycortisol from ng/dL to nmol/L?
Multiply by 0.028863. An 11-deoxycortisol of 40 ng/dL is 1.15 nmol/L. Divide by 0.028863 to go back, or divide the ng/dL figure by about 35 as a mental check. The factor comes from the molecular weight, 346.47.
What does a raised 11-deoxycortisol mean?
First check whether the sample was drawn during a metyrapone test, where a high value is the intended result. Outside that setting the classic cause is 11β-hydroxylase deficiency, in which the block sits immediately after 11-deoxycortisol, so it and deoxycorticosterone accumulate while cortisol falls and adrenal androgens rise.
What 11-deoxycortisol level is a normal metyrapone response?
Published thresholds cluster around 200 nmol/L, which is about 6,900 ng/dL: the UK Supra-Regional Assay Service uses >200 nmol/L for the overnight test, ARUP quotes >8,000 ng/dL (231 nmol/L) after stimulation, and a 2026 series of 190 patients derived an optimal cut-off of 197 nmol/L. Mayo instead states that below 1,700 ng/dL (49 nmol/L) adrenal insufficiency is probable. Use your own laboratory’s threshold with its own protocol.
Why does a metyrapone test need the cortisol as well?
Because the cortisol tells you whether the enzyme was actually blocked. If cortisol did not fall, metyrapone did not work — through non-adherence, dose or timing — and a low 11-deoxycortisol then says nothing about the pituitary or the adrenal. The UK criterion makes the cortisol condition explicit: the test is interpretable only if cortisol fell below 200 nmol/L.
Does a normal 11-deoxycortisol exclude 11β-hydroxylase deficiency?
No. Mayo notes that baseline elevation is not always present, so a normal basal value does not exclude the diagnosis; ACTH stimulation is what settles it. The steroid should also be read alongside 17-hydroxyprogesterone and the adrenal androgens rather than on its own.
Related calculators
References
- Mayo Clinic Laboratories. Test ID: DCORT — 11-Deoxycortisol, Serum. Liquid chromatography tandem mass spectrometry. Reference values: 18 years and under <344 ng/dL; over 18 years 10–79 ng/dL. "Serum 11-deoxycortisol levels below 1700 ng/dL when measured 8 hours after metyrapone administration is indicative of probable adrenal insufficiency."
- ARUP Laboratories. Test 0092331 — 11-Deoxycortisol Quantitative by HPLC-MS/MS, Serum or Plasma. Adults 18 years and older: female <33 ng/dL, male 8000 ng/dL.
- UK Supra-Regional Assay Service. 11-Deoxycortisol. Overnight metyrapone test: normal pituitary response >200 nmol/L, interpretable only if cortisol fell below 200 nmol/L.
- 11-deoxycortisol, other hormones and pituitary function characteristics in the diagnosis of adrenal insufficiency in the overnight oral metyrapone test. Endocr Connect. 2026;15(8):e260261. n=190; optimal cut-off 197 nmol/L, sensitivity 83%, specificity >90%, AUROC 0.907.
- Speiser PW, Arlt W, Auchus RJ, et al. Congenital Adrenal Hyperplasia Due to Steroid 21-Hydroxylase Deficiency: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2018;103(11):4043–4088. doi:10.1210/jc.2018-01865
Medical Disclaimer: The tools and content provided here are for educational and reference purposes only. They are not intended to substitute for professional medical advice, diagnosis, or treatment. Clinical decisions should always be based on the comprehensive assessment of a qualified healthcare professional.