This is an example of the "manufacturer" submitted bioavailability study:

http://www.ncbi.nlm.nih.gov/pubmed?t...-lipoic%20acid

This is unique I think, as other nutrient investigations typically measure patient response for "effectiveness".

There are some small studies on ALA on PubMed too.

Magnesium studies in bioavailability are new too.

There is also one study on B12 bioavailability ..I have quoted on the B12 sticky. One researcher actually measured the amount in micrograms absorbed from an oral 1000mcg dose daily.
http://www.ncbi.nlm.nih.gov/pmc/arti...able/T1/#TF1-4

Bioavailability is a concept that has to be proven for RX medications to the FDA for approval. It has not been applied until recently to nutrients, because of expense doing the studies, etc.

Some products that are used in studies themselves, have to prove
stability, and consistent absorption levels. An example of this is curcumin...which typically is not well absorbed. Some products like LongVida Curcumin have done bioavailability studies for this reason.

Just be careful in your dosing, when using the new R-lipoic... it just doesn't need those high ALA doses because of its chemical differences.