Originally Posted by mrsD

Not much is known about this supplement for humans. The amounts in nature are very small, tiny in fact. And the only supplement is 10mg which compared to what nature provides is HUGE... If you click on PubMed link at the top right of each page here and keyword in Coenzyme PQQ you can see the titles of the papers....highly theoretical and technical still with few if any human studies.
This one is a theoretical paper:
http://www.ncbi.nlm.nih.gov/pubmed/19803551

So the disclaimer.... this takes the manufacturer off the hook and places responsibility on the patient taking it OTC.

In fact we have a similar disclaimer at the bottom of each page here.

In this case I would not expect very many doctors to know what PQQ is.