Comparing Tolerability and Absorption of Racemic and R-lipoic Acid in Progressive Multiple Sclerosis

This three-week double-blind crossover trial will compare two different forms of lipoic acid (LA). Every participant will take one week of daily oral 600mg R LA, have a one week washout period without LA, and take one week of daily oral 1200mg racemic LA. The order of LA type will be determined by randomization. Blood analyses will be performed to determine which form is better absorbed and a side effects questionnaire will be completed at each visit in order to determine which form is better tolerated.