4β-Hydroxycholesterol-d4 is the deuterium labeled 4β-Hydroxycholesterol. 4β-hydroxy Cholesterol is a major oxysterol cholesterol metabolite and a precursor in the synthesis of bile acids that is found in human circulation[1][2].
Stable heavy isotopes of hydrogen, carbon, and other elements have been incorporated into drug molecules, largely as tracers for quantitation during the drug development process. Deuteration has gained attention because of its potential to affect the pharmacokinetic and metabolic profiles of drugs[1].
References:
[1]. Russak EM, et al. Impact of Deuterium Substitution on the Pharmacokinetics of Pharmaceuticals. Ann Pharmacother. 2019 Feb;53(2):211-216.
[2]. Granchi C, Rizzolio F, Bordoni V, Caligiuri I, Manera C, Macchia M, Minutolo F, Martinelli A, Giordano A, Tuccinardi T. 4-Aryliden-2-methyloxazol-5(4H)-one as a new scaffold for selective reversible MAGL inhibitors. J Enzyme Inhib Med Chem. 2016;31(1):137