Pycnogenol

Pycnogenol is a registered trade name for a standardized extract of the bark of the French maritime pine, Pinus pinaster ^[1][3]. Chemical analysis shows it to be composed mainly of procyanidins, which are polymers of the flavonoids catechin and epicatechin, together with phenolic acids and the flavonoid taxifolin; the procyanidins range from single units to oligomers of seven or more subunits ^[1]. Commercial preparations are standardized to contain a high proportion of procyanidins, and these polyphenols are the basis of the extract's antioxidant reputation ^[1][3].

The extract traces back to the French researcher Jacques Masquelier, who became interested in the medicinal use of pine bark after reading historical accounts of bark preparations used by Indigenous peoples of North America ^[3]. Masquelier isolated proanthocyanidins from maritime pine bark and coined the name Pycnogenol, which today is a proprietary product of a single manufacturer rather than a generic ingredient ^[3].

Pycnogenol has been promoted for an unusually broad list of uses, including chronic venous insufficiency, high blood pressure, diabetes and its complications, asthma, attention deficit hyperactivity disorder, erectile dysfunction, osteoarthritis, and skin protection ^[1][2]. Early reviews by researchers close to the product reported favourable effects on circulation, oxidative stress, and inflammation ^[1]. Independent assessment has been more cautious: successive Cochrane systematic reviews, the most recent pooling twenty-seven randomized trials in more than sixteen hundred participants across some ten chronic disorders, found the individual studies to be small, varied, and often at risk of bias, and concluded that no definitive judgement about the extract's efficacy or safety was possible and that current evidence is insufficient to support its use for any chronic condition ^[2][3]. Larger, well-designed trials were called for ^[2].

Pycnogenol is regulated and sold as a dietary supplement, most often in capsule or tablet form, and it is not licensed as a drug ^[2]. Reviews describe it as having low toxicity, with only mild and infrequent side effects, chiefly minor gastrointestinal complaints, reported after oral use ^[1]. Because it is a proprietary supplement, its manufacture is standardized by the producer, but as with other supplements it is not subject to the same pre-market approval required of pharmaceuticals ^[2].

Well tolerated; mild GI upset, dizziness, or headache are the most common complaints. Because it can lower blood pressure and has mild blood-thinning effects, use caution with antihypertensives or anticoagulants. Generally considered safe for extended use.