A low power adaptive controlled current-reusing received signal strength indicator (RSSI) is proposed for the human body communication (HBC). The proposed RSSI has three low power features. First, the power on controller (PoC) scheme is proposed to achieve the duty control of the RSSI. It significantly reduces the average power consumption of RSSI over 90%. Second, the current stacking scheme is adopted to share both eight rectifiers and eight amplifiers, composing the RSSI. By the current reusing technique, the power consumption of the RSSI is reduced to 45%. In addition, the reconfigurable LNA is used in the front-end of HBC TRX. The RSSI adaptively controls the gain and noise figure of the LNA to optimize the power consumption. The proposed RSSI occupies 0.85mm² in 0.18-μm CMOS technology.