Biomedical implantable sensors transmitting a variety of physiological signals have been proven very useful in the management of chronic diseases. Currently, the vast majority of these in-body wireless sensors communicate in frequencies below 1 GHz. Although the radio propagation losses through biological tissues may be lower in such frequencies, e.g., the medical implant communication services (MICS) band of 402-405 MHz, the maximal channel bandwidths allowed therein constrain the implantable devices to low data rate transmissions. Novel and more sophisticated wireless in-body sensors and actuators may require higher data rate communication interfaces. Therefore, the radio spectrum above 1 GHz for the use of wearable medical sensing applications should be considered for in-body applications too. Wider channel bandwidths and smaller antenna sizes may be obtained in frequency bands above 1 GHz at the expense of larger propagation losses. Therefore, in this paper we present a phantom-based radio propagation study for the frequency bands of 2360-2400 MHz, which has been set aside for wearable body area network (BAN) nodes, and the industrial, scientific, medical (ISM) band of 2400-2483.5 MHz. Three different channel scenarios were considered for the propagation measurements: in-body to in-body (IB2IB), in-body to on-body (IB2OB), and in-body to off-body (IB2OFF). We provide for the first time path loss formulas for all these cases.