Activin 50 mg by Natrol

What do they do?

Proanthocyanidins—also called "OPCs" for oligomeric procyanidins or "PCOs" for procyanidolic oligomers—are a class of nutrients belonging to the flavonoid family.

Proanthocyanidins have antioxidant activity and they play a role in the stabilization of collagen and maintenance of elastin—two critical proteins in connective tissue that support organs, joints, blood vessels, and muscle.^{1 2} Possibly because of their effects on blood vessels, proanthocyanidins have been reported in double-blind research to reduce the duration of edema after face-lift surgery from 15.8 to 11.4 days.³ In preliminary research, proanthocyanidins were reported to have anti-mutagenic activity (i.e., to prevent chromosomal mutations).⁴

Proanthocyanidins have been shown to strengthen capillaries in double-blind research using as little as 100 mg per day.⁵ In another double-blind trial, French researchers reported that women with chronic venous insufficiency had reduced symptoms using 150 mg per day.⁶ In another French double-blind trial, supplementation with 100 mg taken three times per day, resulted in benefits within four weeks.⁷

Proanthocyanidins (200 mg per day for five weeks) have improved aspects of vision (visual performance in the dark and after exposure to glare) in healthy people.^{8 9} A product that is high in proanthocyanidins has been shown to prevent and reverse abnormal blood clotting in smokers.¹⁰