Here is some history to start with:
http://ntp.niehs.nih.gov/ntp/htdocs/...nebark_508.pdf
Since starting with Pycnogenol in 1995 and I got on this OPC as we were lectured that it MAY prevent cancer(s). The first thing to leave my body was a lifetime of allergy/sinus issues. I have NOT taken a drug for the allergy/issues since that time...in my 21st year.
Pycnogenol was just arriving in the U.S. from France.
I have posts on the vitamin section here. Also in the Allergy section.