00 CAR Content Vol 22 9 HT46 A purine derivative, paraxanthine, promotes cysteine uptake for glutathione synthesis ScienceDirect Paraxanthine, a compound your body creates when it breaks down caffeine, is being touted by some as a better alternative to coffee, offering energy and focus without the jitters. Click the link New Preclinical Study Shows Paraxanthine Enhances Memory and Brain Function Better Than Caffeine