Piperine is the alkaloid responsible for the spiciness of black pepper and long pepper.
The piperine - curcumin association has been proposed to improve the bioavailability of the latter. In fact, we have seen how piperine can increase the bioavailability of curcumin by 2000% (ie 20 times). In the study in question, 20 mg of piperine was used in combination with 2 grams of curcumin. Without this association, the intake of 2 grams of curcumin had not produced a significant increase in its blood levels, confirming the very low bioavailability.
It is precisely the limited capacity for intestinal absorption - together with rapid hepatic metabolism - to significantly reduce the bioavailability of curcumin, limiting the surprising in vivo clinical effects to a clinical level.
