The drug of abuse γ-hydroxybutyric acid (GHB) demonstrates complex toxicokinetics with dose-dependent metabolic and renal clearance. GHB is a substrate of monocarboxylate transporters (MCTs) which are responsible for the saturable renal reabsorption of GHB. MCT expression is observed in many tissues and therefore may impact the tissue distribution of GHB. The objective of the present study was to evaluate the tissue distribution kinetics of GHB at supratherapeutic doses. GHB (400, 600, and 800mg/kg iv) or GHB 600mg/kg plus L-lactate (330mg/kg iv bolus followed by 121mg/kg/h infusion) was administered to rats and blood and tissues were collected for up to 330min post-dose. K p values for GHB varied in both a tissue- and dose-dependent manner and were less than 0.5 (except in the kidney). Nonlinear partitioning was observed in the liver (0.06 at 400mg/kg to 0.30 at 800mg/kg), kidney (0.62 at 400mg/kg to 0.98 at 800mg/kg), and heart (0.15 at 400mg/kg to 0.29 at 800mg/kg), with K p values increasing with dose consistent with saturation of transporter-mediated efflux. In contrast, lung partitioning decreased in a dose-dependent manner (0.43 at 400mg/kg to 0.25 at 800mg/kg) suggesting saturation of active uptake. L-lactate administration decreased K p values in liver, striatum, and hippocampus and increased K p values in lung and spleen. GHB demonstrates tissue-specific nonlinear distribution consistent with the involvement of monocarboxylate transporters. These observed complexities are likely due to the involvement of MCT1 and 4 with different affinities and directionality for GHB transport.