Another traditional remedy for CVI is butcher’s broom. One double-blind trial used a combination of butcher’s broom, the flavonoid hesperidin, and vitamin C. This was found to be better than a placebo for treating CVI.¹ In a comparison study, a product combining butcher’s broom extract, the flavonoid hesperidin, and vitamin C was more effective than a synthetic flavonoid product for treating CVI.² A double-blind study, in which Butcher's broom alone was used, has confirmed the beneficial effect of this herb.³ Clinical trials have used one capsule, containing standardized extracts providing 15 to 30 mg of ruscogenins, three times each day. The amount of butcher’s broom extract used in these trials is 150 mg two times per day. Other sources recommend standardized extracts providing 15 to 30 mg of ruscogenins, given three times each day.

Flavonoids promote venous strength and integrity. Most trials of flavonoids in patients with CVI have used a type of flavonoid called hydroxyethylrutosides (HR), which is derived from rutin. These double-blind and other controlled trials have consistently shown a beneficial effect of HR in clearing leg swelling and other signs of CVI.^4,5,6 Positive results from a double-blind trial have been obtained using 500 mg of HR taken twice per day for 12 weeks.⁷ In this trial, the preparation was found to add further benefit to that provided by compression stockings commonly used to treat CVI. Similar results were obtained in another controlled trial.⁸ It is unclear whether other flavonoids are as effective as HR for CVI. HR has also been used successfully as a topical preparation for the treatment of CVI.⁹

According to an extensive overview of clinical trials, standardized horse chestnut seed extract, which contains the active compound aescin, has been shown to be effective in double-blind and other controlled research, supporting the traditional use of horse chestnut for venous problems.¹⁰ In these trials, capsules of horse chestnut extract containing 50 mg of aescin were given two to three times daily for CVI. The positive effect results in part from horse chestnut’s ability to strengthen capillaries, which leads to a reduction in swelling.¹¹

Proanthocyanidins (OPCs), a group of flavonoids found in pine bark, grape seed, grape skin, bilberry, cranberry, black currant, green tea, black tea, and other plants, have also been shown to strengthen capillaries in double-blind research using as little as two 50 mg tablets per day.¹⁹ In a double-blind trial using a total of 150 mg OPCs per day, French researchers reported reduced symptoms for women with CVI.²⁰ In another French double-blind trial, supplementation with 100 mg taken three times per day resulted in benefits within four weeks.²¹

Gotu kola extracts, standardized to triterpenoid content, have been found successful in small preliminary trials to treat CVI.²² The amount of extract used in these trials ranged from 60 to 120 mg per day.

A double-blind trial demonstrated that red vine leaf extract is effective at relieving the symptoms and swelling associated with CVI.²³ One group of participants took either 360 mg or 720 mg per day of a standardized extract for 12 weeks, and another group took a placebo. At the end of the treatment period, those who had taken the herb experienced significant improvement in symptoms of leg heaviness, tension sensation, tingling, and pain compared with those who had taken the placebo. Objective measurements of leg swelling were also significantly improved in the red vine group compared to the placebo group.