Organic Citrus Bergamot Extract - High Strength 38% Bergamot Polyphenols - Clinically Studied BPF®. HIGH STRENGTH FORMULA WITH CLINICALLY STUDIED BPF® CERTIFIED ORGANIC. BPF® (Bergamot Bioactive Polyphenolic Fractions) is the most widely studied extract of the Bergamot fruit’s juice and albedo, which has a unique profile of flavonoids and glycosides.