The paper aims at exploring advantages and drawbacks of using high-frequency inductive links to transmit power wirelessly to implanted biosensors. A system with an external transmitting coil located into a skin patch and a receiving coil embedded into a fully implanted biosensor is simulated. The effects of the geometry of the coils on the optimal working frequencies and on the power gain have been analyzed. For applications dedicated to elderly and chronic patients, attention has been posed to the effects on link efficiency of different implantation sites and possible misalignments between the coils.