 Analysis of ALS databases revealed that higher urate levels are an independent predictor of slower progression and prolonged survival in ALS. However, whether elevating urate in people with ALS would result in better outcomes is unknown. As a first step towards development of inosine as a potential treatment for ALS, in this study we will test whether inosine administration in ALS is safe and correlates with changes in the levels of biomarkers of oxidative stress and damage as biomarkers of the intended biological effect. 