Background: Despite its broad range of biological activities, use of curcumin is limited because of poor bioavailability. Here we report a novel curcumin formulation, Curcuwin Ultra? (CU?), with superior bioavailability as compared to 95% turmeric extract (TUR 1800). Methods: A randomized, double-blind, threetreatment, crossover oral bioavailability study was conducted in 24 healthy volunteers under fasting conditions. Subjects received a single dose of CU? 250 mg, 500 mg and 1900 mg of TUR1800 as per randomization schedule and blood samples were collected at 4 h and 0 h before dosing, and 0.5,