Curcumin, found in supplement form at your natural health store, is the active ingredient of the turmeric plant. Prized for its yellow hue and medicinal properties for, reportedly, 4,000 years, turmeric’s unique qualities are found in its curcuminoid components. Extracted from the turmeric (Curcumin longa L) plant, curcumin research has uncovered plenty of reasons to turn (to) yellow.