[(3R)-3-Hydroxydodecanoyl]-L-carnitine is an endogenous metabolite[1]. [1]. Hunter WG, et al. Metabolomic Profiling Identifies Novel Circulating Biomarkers of Mitochondrial Dysfunction Differentially Elevated in Heart Failure With Preserved Versus Reduced Ejection Fraction: Evidence for Shared Metabolic Impairments in Clinical Heart Failure. J Am Heart Assoc. 2016;5(8):e003190. Published 2016 Jul 29.