2-Oxo-3-hydroxy-LSD

2-Oxo-3-hydroxy-LSD
Clinical data
Other names	2-Oxy-3-hydroxy-LSD; OH-LSD; O-H-LSD; 2-Oxo-3-OH-LSD; 2-Oxo-3-hydroxy-2,3-dihydro-LSD; 2-Oxo-3-hydroxylysergide; 2-Oxo-3-hydroxylysergic acid diethylamide; N,N-Diethyl-2,3-dihydro-2-oxo-3-hydroxylysergamide; N,N-Diethyl-3-hydroxy-6-methyl-2-oxo-9,10-didehydro-2,3-dihydroergoline-8β-carboxamide
Drug class	Serotonin receptor modulator
ATC code	None;
Identifiers
	IUPAC name (6aR,9R)-N,N-diethyl-5a-hydroxy-7-methyl-5-oxo-6,6a,8,9-tetrahydro-4H-indolo[4,3-fg]quinoline-9-carboxamide;
CAS Number	111295-09-1;
PubChem CID	10155149;
ChemSpider	8330657;
UNII	KU55DR6345;
CompTox Dashboard (EPA)	DTXSID00436244 ;
Chemical and physical data
Formula	C20H25N3O3
Molar mass	355.438 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES CCN(CC)C(=O)[C@H]1CN([C@@H]2CC3(C4=C(C2=C1)C=CC=C4NC3=O)O)C;
	InChI InChI=1S/C20H25N3O3/c1-4-23(5-2)18(24)12-9-14-13-7-6-8-15-17(13)20(26,19(25)21-15)10-16(14)22(3)11-12/h6-9,12,16,26H,4-5,10-11H2,1-3H3,(H,21,25)/t12-,16-,20?/m1/s1; Key:YSZSHHCNLVHCNV-VRORWYBRSA-N;

2-Oxo-3-hydroxy-LSD, or 2-oxy-3-hydroxy-LSD, also known as O-H-LSD or OH-LSD, as well as more fully as 2-oxo-3-hydroxy-2,3-dihydro-LSD, is a lysergamide and the major metabolite of the psychedelic drug lysergic acid diethylamide (LSD). LSD is eliminated 13% as O-H-LSD in urine within 24 hours and urinary concentrations of O-H-LSD are 4 to 40 times those of LSD in humans.

The specific enzymes responsible for the formation of O-H-LSD from LSD are unclear. However, subsequent research found involvement of several cytochrome P450 enzymes. O-H-LSD is thought to form from other LSD metabolites like 2-oxo-LSD and 3-hydroxy-LSD.

It is unknown whether O-H-LSD is pharmacologically active or produces hallucinogenic effects. However, O-H-LSD showed profoundly reduced albeit still detectable activity at the serotonin 5-HT₂ receptors, including the serotonin 5-HT_2A, 5-HT_2B, and 5-HT_2C receptors, compared to LSD in vitro.

O-H-LSD was first described in the scientific literature by at least the 1990s. It started being sold online as an analytical standard by 2024.