This paper presents a wirelessly powered, batteryless bipolar biphasic constant current stimulator (CCS) for gastric application. The proposed current stimulator employs a 0X/1X regulating rectifier to realize voltage rectification and regulation in one stage. Thus, an additional dc-dc converter for internal controller voltage generation, which occupies a large volume and reduces receiver efficiency, is eliminated. A positive voltage charge pump and a bipolar biphasic constant-current stimulator are integrated together to demonstrate bipolar biphasic stimulation with a maximum stimulation current of 6 mA and a step of 0.2 mA. The chip was fabricated in a 0.18-μm HV CMOS technology. A measured maximum rectifier PCE is 84.8%, and peak charge pump PCE is 60%.