A number of flavonoids have been shown to have anti-inflammatory effects and/or to strengthen blood vessels. These effects could, in theory, be beneficial for people with hemorrhoids. Most,^4,5,6,7 but not all,⁸ double-blind trials using a group of semisynthetic flavonoids (hydroxyethylrutosides derived from rutin) have demonstrated significant improvements in itching, bleeding, and other symptoms associated with hemorrhoids when people used supplements of 600–4,000 mg per day.

Other trials have evaluated Daflon, a product containing the food-derived flavonoids diosmin (90%) and hesperidin (10%). An uncontrolled trial reported that Daflon produced symptom relief in two-thirds of pregnant women with hemorrhoids.⁹ Double-blind trials have produced conflicting results about the effects of Daflon in people with hemorrhoids.^10,11 Amounts of flavonoids used in Daflon trials ranged from 1,000 to 3,000 mg per day. Diosmin and hesperidin are available separately as dietary supplements.

Some doctors recommend flavonoid supplements for people with hemorrhoids. However, many different flavonoids occur in food and supplements, and additional research is needed to determine which flavonoids are most effective against hemorrhoids.

Horse chestnut extracts have been reported from a double-blind trial to reduce symptoms of hemorrhoids.¹² Some doctors recommend taking horse chestnut seed extracts standardized for aescin (also known as escin) content (16–21%), or an isolated aescin preparation, providing 90 to 150 mg of aescin per day.

Constipation is believed to worsen hemorrhoid symptoms, and thus, bulk-forming fibers are often recommended for those with hemorrhoids. A double-blind trial reported that 7 grams of psyllium, an herb high in fiber, taken three times daily reduced the pain and bleeding associated with hemorrhoids.¹³ Some healthcare professionals recommend taking two tablespoons of psyllium seeds or 1 teaspoon of psyllium husks two or three times per day mixed with water or juice. It is important to maintain adequate fluid intake while using psyllium.

Topically applied astringent herbs have been used traditionally as a treatment for hemorrhoids. A leading astringent herb for topical use is witch hazel,¹⁴ which is typically applied to hemorrhoids three or four times per day in an ointment base.