Maritime pine (Pinus pinaster) bark extract, commonly known as Pycnogenol, is supported by scientific evidence for its role in supporting capillary and overall vascular health. Several clinical studies have investigated its effects on microcirculation, capillary permeability, and vascular function. The extract is rich in procyanidins, bioflavonoids, and phenolic acids, which are believed to strengthen capillary walls, protect endothelial cells, and reduce oxidative stress and inflammation.

Research has demonstrated that Pycnogenol supplementation can improve symptoms in chronic venous insufficiency, such as edema and leg heaviness, which are closely linked to capillary function. A 2012 meta-analysis in Phytomedicine concluded that Pycnogenol significantly reduced leg swelling and improved microcirculation in patients with venous disorders. Additional randomized controlled trials have shown that Pycnogenol reduces capillary permeability and fragility, leading to fewer microbleeds and bruising, particularly in populations with weakened capillary integrity (e.g., elderly, diabetic patients).

The European Medicines Agency recognizes the traditional use of maritime pine bark extract for the relief of minor venous circulatory disturbances. However, the bulk of the evidence supporting its benefits for capillaries is scientific, with multiple peer-reviewed studies and meta-analyses supporting its efficacy and safety when used for vascular health.