The article reviews the latest advancements in flexible energy harvesters and their integration with wearable devices, highlighting their potential in biomedical applications. Flexible energy harvesters, including biofuel cells (BFCs), mechanical energy harvesters, radio frequency (RF) energy harvesters, and solar cells, are discussed in detail. BFCs, which convert biochemical energy from bodily fluids into electrical energy, are particularly promising for wearable applications due to their biocompatibility and adaptability to dynamic skin surfaces. Mechanical energy harvesters, such as piezoelectric and triboelectric nanogenerators, can generate power from human motions and vibrations, offering long-term energy sources for bioelectronic implants and environmental monitoring. RF energy harvesters, which convert RF signals into usable power, are efficient for powering small electronic devices and sensors. Solar cells, including organic and perovskite-based systems, are being developed to harness sunlight for powering wearable devices and implants. The article also discusses the challenges and future perspectives of self-powered biomedical systems, emphasizing the need for sustainable and reliable power solutions in wearable healthcare monitoring and management.The article reviews the latest advancements in flexible energy harvesters and their integration with wearable devices, highlighting their potential in biomedical applications. Flexible energy harvesters, including biofuel cells (BFCs), mechanical energy harvesters, radio frequency (RF) energy harvesters, and solar cells, are discussed in detail. BFCs, which convert biochemical energy from bodily fluids into electrical energy, are particularly promising for wearable applications due to their biocompatibility and adaptability to dynamic skin surfaces. Mechanical energy harvesters, such as piezoelectric and triboelectric nanogenerators, can generate power from human motions and vibrations, offering long-term energy sources for bioelectronic implants and environmental monitoring. RF energy harvesters, which convert RF signals into usable power, are efficient for powering small electronic devices and sensors. Solar cells, including organic and perovskite-based systems, are being developed to harness sunlight for powering wearable devices and implants. The article also discusses the challenges and future perspectives of self-powered biomedical systems, emphasizing the need for sustainable and reliable power solutions in wearable healthcare monitoring and management.