Tetrahydrocurcumin is an antioxidant and skin-whitening ingredient. It is a major curcuminoid metabolite of curcumin that has been shown to have protective effects against diabetes and vascular dysfunction via alleviation of oxidative stress.The interest in tetrahydrocurcumin research is increasing because it is superior to curcumin in its solubility in water, chemical stability, bioavailability, and anti-oxidative activity. Curcumin metabolizes into tetrahydrocurcumin by bacterial enzyme NADPH-dependent curcumin reductase in the intestine.
