Proof-of-pharmacology models to study compounds in healthy subjects offer multiple advantages. Simvastatin is known to induce mitochondrial dysfunction at least partly by depletion of co-enzyme Q10. The goal of this study was to evaluate a model of simvastatin-induced mitochondrial dysfunction in healthy subjects and to determine whether mitochondrial dysfunction could be pharmacologically reversed by treatment with co-enzyme Q10 (ubiquinol). Subjects received simvastatin 40mg/day for 8 weeks. After 4 weeks, subjects were randomized to receive ubiquinol 300mg/day or placebo in a double-blinded fashion. Mitochondrial function was assessed by measuring the phosphocreatine recovery time (τ-PCr) using phosphorous Magnetic Resonance Spectroscopy ((31)P-MRS) after in-magnet exercise. After 4 weeks of simvastatin treatment, τ-PCr prolonged with 15.2% compared to baseline, (95%CI, 2.5-29.4%; P = 0.018, Fig. 3). After 8 weeks, τ-PCr further prolonged to 37.27s in the placebo group (prolongation of 18.5% compared to baseline, still significantly prolonged, 95%CI, 1.1-38.9%; P = 0.037), but shortened to 33.81s in the ubiquinol group (prolongation of 9.1% compared to baseline, no longer significantly prolonged, 95%CI, -7.9 to 29.2%; P = 0.31). At 8 weeks, there was no significant difference between groups (difference of 8.2%, 95%CI, -14.5 to 37.0%; P = 0.51). Simvastatin induces subclinical mitochondrial dysfunction in healthy subjects, which can be partly reversed by treatment with ubiquinol. This model of pharmacologically induced and reversed mitochondrial dysfunction can be used to study the effects of compounds that enhance mitochondrial function in healthy subjects.