[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Biochemistry](https://durgical.com/en/biochemistry/) › 17-Hydroxyprogesterone (17-OHP)

[Biochemistry](https://durgical.com/en/biochemistry/) · Molecule

# 17-Hydroxyprogesterone (17-OHP)

An intermediate of cortisol synthesis; it piles up when 21-hydroxylase is missing, which is why newborn screening measures it.

Updated 2026-11-01

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## Key facts

- It is the 21-hydroxylase substrate on the cortisol pathway: 17-OHP → 11-deoxycortisol.
- It rises sharply in 21-hydroxylase deficiency and spills into androstenedione and testosterone.
- It is measured in heel-prick blood in newborn screening; prematurity and stress give false positives.
- In the non-classic form it may be normal at rest and rise only after ACTH stimulation.

**Also called**
17-OHP, 17α-Hydroxyprogesterone

**Formula**
C21H30O3

**PubChem**
[CID 6238](https://pubchem.ncbi.nlm.nih.gov/compound/6238)

## Structure

- Progesterone with a hydroxyl group on carbon 17α (a 21-carbon steroid).
- 17α-Hydroxylase (CYP17A1) makes it and 21-hydroxylase (CYP21A2) uses it up.

## Clinical notes

- A very high 17-OHP in a newborn with ambiguous genitalia or with vomiting and low sodium points to congenital adrenal hyperplasia.
- In a woman with hirsutism it is measured in the early follicular phase to tell non-classic deficiency from polycystic ovaries.
- It also rises, though less, in 11β-hydroxylase deficiency.

## Pathways

- [Adrenal cortisol synthesis](https://durgical.com/en/biochemistry/pathways/adrenal-cortisol-synthesis/)

## Related conditions

- [Congenital adrenal hyperplasia due to 21-hydroxylase deficiency](https://durgical.com/en/conditions/congenital-adrenal-hyperplasia-due-to-21-hydroxylase-deficiency/)
- [Congenital adrenal hyperplasia due to 11β-hydroxylase deficiency](https://durgical.com/en/conditions/congenital-adrenal-hyperplasia-due-to-11-hydroxylase-deficiency/)
- [Polycystic ovary syndrome](https://durgical.com/en/conditions/polycystic-ovary-syndrome/)

## Related

- [21-Hydroxylase (CYP21A2)](https://durgical.com/en/biochemistry/enzymes/21-hydroxylase/)
- [17α-Hydroxylase/17,20-lyase (CYP17A1)](https://durgical.com/en/biochemistry/enzymes/17-hydroxylase-17-20-lyase/)
- [Adrenal enzymes and congenital adrenal hyperplasia](https://durgical.com/en/biochemistry/topics/adrenal-enzymes-and-congenital-adrenal-hyperplasia/)
- [Cortisol](https://durgical.com/en/biochemistry/molecules/cortisol/)

## Test yourself

Think of the answer, then tap the question to see it.

## Which enzyme uses up 17-hydroxyprogesterone on the cortisol pathway?

21-Hydroxylase (CYP21A2), which turns it into 11-deoxycortisol.

## Why can a premature newborn have a false-positive screen?

Because prematurity and stress raise 17-hydroxyprogesterone without any enzyme deficiency.

## Which test is used when the non-classic form is suspected and basal 17-OHP is borderline?

ACTH stimulation, which makes 17-OHP rise sharply if 21-hydroxylase is deficient.

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Molecules are shown in their neutral form, as the databases deposit them; in the cell the acids and phosphates are ionised.

Educational information, not medical advice. For any symptom, see a health professional.

Sources: [17-Hydroxyprogesterone (CID 6238)](https://pubchem.ncbi.nlm.nih.gov/compound/6238) (PubChem, NCBI, 2026) · Public domain; [21-hydroxylase deficiency: MedlinePlus Genetics](https://medlineplus.gov/genetics/condition/21-hydroxylase-deficiency/) (MedlinePlus, US National Library of Medicine, 2026); Textbook of Biochemistry for Medical Students, 6th ed. (Jaypee Brothers Medical Publishers (Vasudevan DM, Sreekumari S, Vaidyanathan K), 2011).

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Source: https://durgical.com/en/biochemistry/molecules/17-hydroxyprogesterone/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/biochemistry/molecules/17-hydroxyprogesterone/