@helenholland3 - Here's some information that describes the Alpha Lipoic Acid types.

"R-ALA and S-ALA are referred to as “enantiomers” and a combination mixture of both is referred to as a “racemic” mixture. R-ALA is the natural, nutritionally active form found in the body and in food whereas S-ALA is chemically produced in the manufacture of R-ALA and has less, if any nutritional value." - Accurate Education – Alpha Lipoic Acid (ALA) - Accurate Clinic: http://accurateclinic.com/accurate-education-alpha-lipoic-acid-ala/

Here's some more information on the topic: Linus Pauling Institute » Micronutrient Information Center - Lipoic Acid:
https://lpi.oregonstate.edu/mic/dietary-factors/lipoic-acid
R-ALA is used mostly along with other supplements to help peripheral neuropathy. Here is a list of common supplements used to help with neuropathy from the Foundation for Peripheral Neuropathy: https://29fvx519grkh3bdqrc16zioc-wpengine.netdna-ssl.com/wp-content/uploads/2020/10/Supplements.pdf