A fully integrated dual source adaptive thermoelectric and RF energy harvesting circuit is presented. Its boost oscillator, rectifier and boost converter all operate at RF frequency to make inductor and capacitor integration feasible. The oscillator Gm adaptive bias reduces current consumption at higher voltage while assisting startup at lower voltage. The RF input signal further reduces startup voltage through Q-enhanced amplification and super-regenerative mode. Implemented in 28nm CMOS, the self-startup voltage was 110mV without RF input and 85mV at -16dBm input. The boost converter peak output power is 520μW, power conversion efficiency (PCE) is 25% and end-to-end PCE is 10%.