Their mode of action is to inhibit gastric and pancreatic lipases, enzymes that play an important role in the digestion of dietary fat.[2] Lipase inhibitors are classified in the ATC-classification system as A08AB (peripherally acting antiobesity products).[3] Numerous compounds have been either isolated from nature, semi-synthesized, or fully synthesized and then screened for their lipase inhibitory activity[3] but the only lipase inhibitor on the market (October 2016) is orlistat (Xenical, Alli).[4] Lipase inhibitors have also shown anticancer activity, by inhibiting fatty acid synthase.[5]