hi
just found this regarding cortisol and early morning wakenings.
it bothers me also.
The main cause here is stress and high cortisol levels. See, our circadian rhythm directs our cortisol, an awakening hormone, to rise around 3am, in preparation for the next morning. However, if your cortisol levels are already high, which is a consequence of stress, then it's likely you will wake up.
take care xx