Image of cortisol smartwatch (IMAGE) California NanoSystems Institute Caption Cortisol is well-suited for measurement through wearable devices, according to study co-author Sam Emaminejad, because its concentration levels in sweat are similar to its circulating levels Credit Yichao Zhao and Zhaoqing Wang/UCLA Usage Restrictions No restrictions. License Public Domain Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.