The wearable antenna for wireless body area network is trending in recent time. The demand for light weight wearable antennas for body area networks is increasing day by day, as an antenna is one of the main elements of wireless body area network. Communication has been established by WBAN between various devices by placing them on the human body. Different types of miniaturized microstrip patch antennas play a different important role. This paper presents a small-sized, low-profile and flexible antenna using FR-4 material as the substrate. The substrate of an antenna effects on antenna’s characteristics. The designed antenna works at a 2.4 GHz operating frequency and offers less than -10 dB of return loss. The proposed antenna is designed for the purpose of achieving a low human body SAR model and suggested for the continuous monitoring of vital human signs such as blood pressure, heart rate and body temperature utilizing wireless body area network. The results of the simulation show that the antenna has 2.2 dB gain, 5.4 directivity, -46.05 dB return loss, 95.8 MHz Bandwidth. This antenna has a low profile, low weight, low cost for WBAN application. The parameters such as VSWR, return loss, directivity, and gain of U shape slotted antenna are analyzed using CST software. This flexible and compact antenna is more suitable for various applications, specifically for wireless body area network application.