Avocado/soybean unsaponifiables (ASU) is an extract prepared from avocado and soybean oil. The product has been approved as a prescription drug in France for several years and has now been introduced in Denmark as a food supplement. ASU has been examined in vitro and in animal studies that have showed an anti-inflammatory effect and a stimulatory effect on proteoglycan synthesis in chondrocytes. Four randomized, double-blind, placebo-controlled clinical trials have been published. These studies indicate that ASU has an effect on the symptoms of knee and hip osteoarthritis but not on the structural changes caused by osteoarthritis.