According to research published in the Pharmaceutical Society of Japan’s Biological and Pharmaceutical Journal, researchers examined the role of curcumin’s internal metabolite, curcumin b-D-glucuronide (curcumin monoglucuronide, CMG), by investigating curcumin kinetics and metabolism in the blood. The researchers confirmed that curcumin is conjugated when it passes through the intestinal wall, and that CMG, when orally administered, was not well absorbed. When CMG was injected intravenously into rats, high levels of free-form curcumin, thought to be sufficiently high to be pharmacologically active, were observed.