Curcuminoids
The umbrella term for curcumin and its two related pigment compounds (demethoxycurcumin and bisdemethoxycurcumin), all naturally present in turmeric root. A label reading "Curcuminoids 500mg" describes this baseline, concentrated-but- unmodified material -- not a formulation engineered to help the body absorb it, like a phytosome.
Example
98.1% of on-market curcumin products use plain curcuminoids, the baseline, lowest-absorption form; only 1.9% use a phytosome-type formulation.