This pilot study tests the feasibility of using GSH redox state and high resolution proton NMR spectroscopy (1H-NMR) to detect metabolic changes due to acetominophen and sulfur amino acid deficiency. Our central hypothesis is that the a 2-day sulfur amino acid deficiency will alter acetominophen metabolism, acetominophen will affect sulfur amino acid homeostasis, and the treatments together will alter the global metabolic profile, as measured by 1H-NMR spectroscopy.