people take it for a variety of reasons, most of which does absolutely nothing. its mainly good for confusion of the masses. R-ALA is an anti-oxidant so if i were to take it i would use it for that.
From Wikipedia:
R-enantiomer and S-enantiomer
Normally, only the R-enantiomer of lipoic acid occurs naturally, but the S-enantiomer can assist in the
reduction of the R-enantiomer when a
racemic (50% R-enantiomer and 50% S-enantiomer) mixture is given.
[43] However, some studies have suggested that the S-
enantiomer in fact has an inhibiting effect on the R-enantiomer, reducing its biological activity.
[44] Furthermore, while a racemic mixture of lipoic acid has been found to increase the expression of GLUT4, responsible for glucose uptake in cells, the R-enantiomer of lipoic acid has been shown to do so by a greater amount than either the S-enantiomer or the racemic mixture.
[45] However, as stated by the Linus Pauling Institute, "virtually all of the published studies of LA supplementation in humans have used racemic LA".
[46]