The purpose of this study was to determine whether BN165 (Ginkor Fort), which has been reported to alleviate symptoms of venous insufficiency, has a beneficial effect on lymphatic function or lymphedema symptoms. Using a 3-arm, double-blind, placebo-controlled design in 48 patients with upper extremity lymphedema secondary to breast cancer treatment, improvement in symptoms and signs as well as lymphoscintigraphic kinetic parameters (radiocolloid half-life and lymphatic migration speed) was assessed in response to treatment. A statistically significant effect on limb heaviness was noted. Lymphatic migration speed also demonstrated a significant increase at a dose of 2 active capsules per day but not at the 3 capsules per day dose, but lymphatic migration speed also improved in the placebo group. These findings in mechanical lymphatic insufficiency in breast cancer-related lymphedemas can be compared to the previously published clinical amelioration by BN165 of the subjective symptoms (heavy limbs) of dynamic lymphatic insufficiency in patients with venous insufficiency. Further studies are needed to define the possible role of BN165 in treating patients with lymphedema.