A pharmacokinetic study and critical reappraisal of curcumin formulations enhancing bioavailability

to show biological effects. Curcumin conjugates exceeded 10 nM with all formulations, particularly NovaSOL, which showed 100-fold higher levels. Fecal recovery mainly included unconjugated curcuminoids and was high, except for NovaSOL, suggesting better intestinal absorption. However, even when using a formulation with enhanced uptake, plasma levels of unconjugated curcumin remained minimal. Piperine addition provided no benefit. The findings underscore that bioavailability claims should be based on unconjugated curcumin and not on its poorly membrane permeable conjugates.