--is the active right sided molecular isomer isolated from the various types in alpha lipoic acid; for some reason, the left-sided isomer seems to be inactive in humans.

Part of the reason r lipoic acid was developed was that discovery and the fact that many people taking alpha lipoic acid did experience some acidic stomach/reflux side effects; it was thought that isolating the active isomer would enable people to take lower, less acidic doses for a similar effect.

I've seen people claim that ration of 6:1 alpha vs. r for a similar effect--e.g., that taking 100mg of r produces a similar benefit as 600mg of alpha--but I suspect the ration is rather individual and one might need to experiment somewhat to find out.