For more effective supplement with alpha lipoic acid try R-Fraction Alpha Lipoic Acid by Swanson. Standard alpha lipoic acid supplements have racemic mixture of R and S isomers in a 50:50 ratio but the R isomer is the only form which is naturally occurring in the body and this is the form to which most of the beneficial effects of the alpha-lipoic acid are attributed. Although it is a well-known fact, the efforts to make an effective supplement only with the R form have always been hindered by stability issues. This Swanson formula achieves maximum concentrations of R-alpha lipoic acid in plasma 30 minutes after intake, which are 8 to 10 times higher than those which can be achieved using other alpha lipoic acid supplements.