[6] Rutin is a citrus flavonoid glycoside found in many plants, including buckwheat,[7] the leaves and petioles of Rheum species, and asparagus.

[9] Approximate rutin content of selected foods, in milligrams per 100 milliliters:[10] Rutin (rutoside or rutinoside)[12] and other dietary flavonols are under preliminary clinical research for their potential biological effects, such as in reducing post-thrombotic syndrome, venous insufficiency, or endothelial dysfunction, but there was no high-quality evidence for their safe and effective uses as of 2018.

[12][13][14] A 2020 review indicated that oral rutosides may reduce leg edema in people with post-thrombotic syndrome, but the risk of adverse effects was higher.

[15] As a flavonol among similar flavonoids, rutin has low bioavailability due to poor absorption, high metabolism, and rapid excretion that collectively make its potential for use as a therapeutic agent limited.

DHK can be further hydroxylated by flavonoid 3´-hydroxylase (F3'H) to produce dihydroquercetin (DHQ), which is then catalyzed by flavonol synthase (FLS) to form quercetin.