Devices and methods of forming a compliant gastroplasty are presented. In general, fasteners that can reversibly couple are inserted into gastric tissue to form a gastric restriction. When an expanding pressure in the stomach exceeds a certain limit, the coupled fasteners can decouple to accommodate and relieve the excess pressure. Upon subsequent stomach shrinkage, fasteners are brought back into proximity and recouple to reform the gastroplasty. In particular, magnetic fasteners can be inserted into gastric tissue by injecting a solidifying composition into the tissue to form the fasteners. Various devices and methods for forming the gastroplasty are discussed.