Not intending to be confrontational, but were that true, someone would be selling pure S-isomer.
Fact is, these guys hadn't even thought of this till I raised the issue on these boards about a year and a half ago, even then it was ignored because people in general know nothing about stereoisomerism.
I'd like to see a single reference showing that the S form gets a metal out of the body than the R form and also anything on crossing BBB. To my knowledge, that's all made up, but I'm open to learning.
I wouldnt touch ALA if it were free of charge.
Any chemist worth their salt would recognize immediately the presence of an asymmetric carbon atom in the structure of lipoic acid. In my view, to ignore stereochemistry when dealing with biological systems (as many writers have) is a foolish mistake, since it is well-known that they body's systems, proteins, enzymes, etc. have a handedness.
Don't believe me ? Try a little bit of the wrong isomer (laevorotatory form, "L") of penicillamine and see what happens. No, don't !! It's why L-desoxyephedrine is not remotely as potent as the D-isomer. Amino acids same way. The list is literally endless of differences in activity between enantiomers.