Ingredients antraglikozidy, frangularozid, glyukofrangulin and frangulin, which are the main active substances, free emodiny, resin, starch and pectic substances. Description Buckthorn bark has been used medicinally since at least the 1600s, when it was listed in a primary medical reference called the London Pharmacopeia. Although most herbs have had a wide variety of traditional uses, later refined to a single or a few proven benefits, buckthorn bark throughout its history has been consistently used to relieve one ailment: constipation and its by-products (hemorrhoids and anal irritation). Buckthorn bark contains compounds called anthraquinones, which have a strong purgative, laxative effect on the body. Because these compounds are powerful, before being processed into laxative products the bark is aged for a year, or heated and dried. Buckthorn bark has laxative and cathartic properties.