The presence of edema in different phases and stages of essential hypertension may be due to antihypertensive treatment. Some drugs may cause edema by inducing vasodilatation, increasing the capillary exchange surface and capillary filtration. Pycnogenol has an important anti-edema effect in diabetic microangiopathy and chronic venous insufficiency. This 8-week study evaluated capillary filtration in 2 comparable treatment groups with hypertension treated with a calcium antagonist (nifedipine) or angiotensin-converting enzyme inhibitor to define its efficacy in preventing edema caused by antihypertensives. A significant decrease in filtration was observed in the Pycnogenol groups. Pycnogenol controls this type of edema, it helps to prevent and limit long-term damage in the microcirculation in hypertensive patients, and allows the dose of anti-hypertensive drugs to be reduced in most patients.