Black pepper is the most widely traded spice in the world. It is the dried fruit of the flowering vine Piper nigrum, which is native to India but cultivated across the tropics. As well as being commonly used in cooking and as a seasoning, black pepper has a wide variety of health and medicinal uses.
Piperine is the compound which gives black pepper its pungency and its taste, and it is piperine which is the most active ingredient in black pepper extract. Piperine is known to inhibit glucoronidation, the process which "tags" certain substances for excretion from the body. Because of this, black pepper improves the bioavailability of other supplements in the body, especially curcumin.
In its own right, piperine has a lot to offer the human body. Since ancient times, black pepper was thought to act as a painkiller, and studies have shown that it can reduce inflammation in the body. It is also being investigated for its potential role in treating some diabetic complications.
Piperine is also thought to block the formation of new fat cells, so black pepper extract is sometimes sold as a weight loss supplement. It's known that piperine stimulates digestive juices, and can aid in speeding up metabolism.