A hallmark of prostate cancer is the reprogramming of prostate cancer metabolism which has been exploited for both 31P and 1H MRSI. In recent work, we and others have shown that hyperpolarized substrates can be used in living systems to measure changes in metabolic dynamics. Many studies have focused on the use of HP pyruvate in preclinical models, though the characterization of prostate cancer in man using HP MRI has been limited. In this work, we demonstrate the use of HP pyruvate MRI in prostate cancer patients. We assess the metabolic dynamics to the prostate of pyruvate as well as its conversion to lactate. Moreover we extend this analysis to the comparison of HP lactate to prostate cancer grade showing that not only does this approach have the potential to measure differences in grade it also can provide reproducible metabolic signatures across patients.