Dihydroresveratrol is a polyketide synthase-derived bibenzyl that has been found in C. sativa and has diverse biological activities.^1,2,3,4 It is also an active metabolite of resveratrol that is formed by gut microbiota.⁵ Dihydroresveratrol inhibits DNA polymerase α but not DNA polymerase δ (Kis =29.3 and >100 µM, respectively) and the formation of thiobarbituric acid reactive substances (TBARS) in rat liver microsomes (EC50 = 1.57 µM).² It stimulates the proliferation of hormone-sensitive MCF-7 breast cancer cells but not hormone-resistant MDA-MB-231 and BT474 breast cancer cells when used at concentrations ranging from 0.01 pM to 100 nM.³ Dihydroresveratrol decreases interalveolar septal thickness and alveolar hemorrhage in a rat model of lung injury induced by cerulein- and LPS-stimulated pancreatitis when administered at a dose of 50 mg/kg.⁴