5α-Dihydronorethisterone
chemical compound
5α-Dihydronorethisterone (5α-DHNET, dihydronorethisterone, 17α-ethynyl-5α-dihydro-19-nortestosterone, or 17α-ethynyl-5α-estran-17β-ol-3-one) is a major active metabolite of norethisterone (norethindrone). Norethisterone is a progestin with additional weak androgenic and estrogenic activity. 5α-DHNET is formed from norethisterone by 5α-reductase in the liver and other tissues.
Pharmacology
Unlike norethisterone which is purely progestogenic, 5α-DHNET has been found to possess both progestogenic and marked antiprogestogenic activity, showing a profile of progestogenic activity like that of a selective progesterone receptor modulator (SPRM). Moreover, the affinity of 5α-DHNET for the progesterone receptor (PR) is greatly reduced relative to that of norethisterone at only 25% of that of progesterone (versus 150% for norethisterone).
5α-DHNET shows higher affinity for the androgen receptor (AR) compared to norethisterone with approximately 27% of the affinity of the potent androgen metribolone (versus 15% for norethisterone). However, although 5α-DHNET has higher affinity for the AR than does norethisterone, it has significantly diminished and in fact almost abolished androgenic activity in comparison to norethisterone in rodent bioassays. Similar findings were observed for ethisterone (17α-ethynyltestosterone) and its 5α-reduced metabolite, whereas 5α-reduction enhanced both the AR affinity and androgenic potency of testosterone and nandrolone (19-nortestosterone) in rodent bioassays. As such, it appears that the C17α ethynyl group of norethisterone is responsible for its loss of androgenicity upon 5α-reduction. Instead of androgenic activity, 5α-DHNET has been reported to possess some antiandrogenic activity.
The public source identifies “5α-Dihydronorethisterone” as chemical compound. This brief keeps that definition visible, then builds a research path around 5α-Dihydronorethisterone, chemical and compound.
Why this record matters
A short description can identify a subject without explaining its stakes. For “5α-Dihydronorethisterone”, the useful work is to connect “chemical compound” to the records capable of establishing context and consequence.
The date and method of observation matter as much as the stated conclusion, especially where classification or consensus has changed. The source revision retrieved here is dated Jul 28, 2025. The linked authority identifier is Q39053683.
Scientific names, classifications and consensus can change while older terminology persists in catalogues and historical literature. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Check terminology, classification and the date of the cited evidence. Scientific names and technical consensus can change while older records retain historical value.
- Current terminology
- Classification context
- Finding cited technical literature
Primary datasets, specimen catalogues, standards bodies and the most recent peer-reviewed literature.
Three-step research path
- Establish the record: confirm the title “5α-Dihydronorethisterone”, its source revision and the description used here.
- Expand the search: follow 5α-Dihydronorethisterone primary sources, 5α-Dihydronorethisterone archive and 5α-Dihydronorethisterone research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “5α-Dihydronorethisterone”?
- Is the terminology current, historical or disputed?
- Has classification or technical consensus changed since the cited source?
Search terms from this dossier
This entry incorporates text from “5α-Dihydronorethisterone” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.