Design of implantable devices at 2.4 GHz ISM band for medical examina- tion has been extensively researched ever since IoT has gained importance. Implantable devices need to be small and less power hungry. In this paper, a small size and highly efficient 2.4 GHz miniaturized on-chip loop antenna has been proposed and is suitable for biotelemetry applications. The substrate stack up of on chip antenna consists of 6 metal layers. Antenna is designed on the top most metal layer (M6). Miniaturization is achieved by using the prin- ciple of slot loading and multi-fingered loop loading. The proposed antenna utilizes the surface area within loop antenna to increase the efficiency of pro- posed antenna.The proposed antenna is simulated using Advanced Design Sys- tem (ADS) tool. The gain of the simulated on chip antenna is -13.93 and effi- ciency is 1.91%, which is the highest gain reported at 2.4 GHz. The dimensions of the antenna is 1.5mm x 1.0 mm.