Increasing Post-Digestive Solubility of Curcumin Is the Most Successful Strategy to Improve its Oral Bioavailability: A Randomized Cross-Over Trial in Healthy Adults and In Vitro Bioaccessibility Experiments.

Scope: Different mechanistic approaches to improve the low oral bioavailability of curcumin have been developed, but not yet directly compared in humans.

Methods And Results: In a randomized, double-blind, cross-over trial with 12 healthy adults, the 24 h pharmacokinetics of a single dose of 207 mg curcumin is compared from the following formulations: native, liposomes, with turmeric oils, with adjuvants (including piperine), submicron-particles, phytosomes, γ-cyclodextrin complexes, and micelles. No free, but only conjugated curcumin is detected in all subjects.