Piperine is an alkaloid that gives black pepper (Piper nigrum) its pungency. It is slightly soluble in water and highly soluble in alcohol, chloroform and ether. Piperine has a long history of use in some types of traditional medicine. Its primary commercial use is in modern herbal medicine.
The primary value of piperine in health supplements is its ability to enhance the bioavailability of some other vitamins and minerals. This mechanism is still being studied, but piperine is known to inhibit the enzymes P-glycoprotein and CYP3A4 in humans. These enzymes are involved in the metabolism and transport of various metabolites. Animal studies also show that piperine inhibits CYP 450 enzymes that metabolize many drugs. In particular, piperine may increase the bioavailability of curcumin by a factor of 20.