All of the supplement statements have the FDA disclaimer in the US. This is because almost all of them are NOT drugs.

A very few OTC things do have FDA approval. SAMe is one, and another is the new Salonpas Arthritis patch (10%).

Most of the Benfotiamine and ALA papers come from Europe and for many years.

FDA approval these days, is a controversial thing IMO. I wouldn't worry much about that.

The PubMed link is free to abstracts and at the top right of each page here at NeuroTalk.

Many of Big Pharma's drug trials do go unpublished. These are the negative results as a rule. It has been very contentious here in US over this situation and medical journals. Some progress has been made, but people need to understand this before starting drugs, that have been detailed to doctors using only favorable studies, and where the negative ones have been omitted.

Nutrients like benfotiamine and lipoic acid are not drugs.
You need to keep that in mind. Benfotiamine is a form of thiamine B1 which is a vitamin. Lipoic acid is made in the body naturally. None of the doses here recommended by me are very high. So therefore you are only replacing what you might need and not taking extra.