Desmetramadol

Desmetramadol
Clinical data
Other names	O-Desmethyltramadol; O-DSMT; Omnitram
Pharmacokinetic data
Metabolism	CYP3A4 and CYP2B6
Elimination half-life	6-8 hours
Identifiers
	IUPAC name 3-(2-((dimethylamino)methyl)-1-hydroxycyclohexyl)phenol;
CAS Number	80456-81-1 ;
PubChem CID	130829;
ChemSpider	115703 ;
UNII	2WA8F50C3F;
ChEMBL	ChEMBL1400 ;
CompTox Dashboard (EPA)	DTXSID40894102 ;
Chemical and physical data
Formula	C15H23NO2
Molar mass	249.354 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES OC2(c1cc(O)ccc1)CCCCC2CN(C)C;
	InChI InChI=1S/C15H23NO2/c1-16(2)11-13-6-3-4-9-15(13,18)12-7-5-8-14(17)10-12/h5,7-8,10,13,17-18H,3-4,6,9,11H2,1-2H3 ; Key:UWJUQVWARXYRCG-UHFFFAOYSA-N ;
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Desmetramadol (INNTooltip International Nonproprietary Name), also known as O-desmethyltramadol (O-DSMT), is an opioid analgesic and the main active metabolite of tramadol. Tramadol is demethylated by the liver enzyme CYP2D6 to desmetramadol in the same way as codeine, and so similarly to the variation in effects seen with codeine, individuals who have a less active form of CYP2D6 will tend to have reduced analgesic effects from tramadol. Because desmetramadol itself does not need to be metabolized to induce an analgesic effect, it can be used in individuals with CYP2D6 inactivating mutations.

Desmetramadol is commonly encountered as a designer drug online in powder form or as an ingredient in pressed pills due to being unscheduled in many jurisdictions. Outside of its role as a metabolite, a chemical used in research, and as a recreational drug, desmetramadol has a very limited history of human usage and is not approved for medicinal use in any country as of 2025.