Hesperetin is the 4'-methoxy derivative of eriodictyol, a flavanone. The 7-O-glycoside of hesperetin, hesperidin, is a naturally occurring flavanone-glycoside, the main flavonoid in grapefruits, lemons, and sweet oranges.

Various glycosides of hesperetin are known, including hesperidin (hesperetin-7-O-rutinoside), a water-insoluble flavonoid glycoside with low water solubility, Hesperidin is found in citrus fruits and upon ingestion it releases its aglycone, hesperetin. Neohesperidin is the 7-O-neohesperidoside of hesperetin.

Hesperidin 6-O-α-L-rhamnosyl-β-D-glucosidase is an enzyme that uses hesperidin and H₂O to produce hesperetin and rutinose. Upon digestion in the gastrointestinal tract, hesperetin – as for all flavonoids – is rapidly metabolized in intestinal and liver cells, releasing smaller metabolites into the blood and urine for excretion. The biological effects of such metabolites in vivo are unknown.

In vitro, hesperetin may affect the slow inactivation phase of inward sodium current channels, and therefore could be used as a template to develop drugs against cardiac arrhythmias. Hesperetin also inhibits TRPM3 channels in vitro.