Black pepper (Piper nigrum L.) is a very widely used spice, known for its pungent constituent piperine. However, in addition to its culinary uses, pepper has important medicinal and preservative properties, and, more recently, piperine has been shown to have fundamental effects on p‐glycoprotein and many enzyme systems, leading to biotransformative effects including chemoprevention, detoxification, and enhancement of the absorption and bioavailability of herbal and conventional drugs. Based on modern cell, animal, and human studies, piperine has been found to have immunomodulatory, anti‐oxidant, anti‐asthmatic, anti‐carcinogenic, anti‐inflammatory, anti‐ulcer, and anti‐amoebic properties. In this review, the chemical constituents, biological activities, effects of processing, and future potential of black pepper and piperine have been discussed thoroughly. Copyright © 2013 John Wiley & Sons, Ltd.