Low profile antennas for ingestible devices, such as ingestible event markers, are provided. Aspects of the ingestible devices of the invention include low profile signal transmission antennas configured such that they are flexible or degrade after use, allowing the antenna and attached components to pass easily through the body. Embodiments of the low profile antennas are configured to emit a detectable signal upon contact with a target physiological site. Also provided are methods of making and using the devices of the invention.