cortex is better for low cortisol peeps only as it comes from the cortex, where cortisol is made, the other full spectrum glandular is better if you have other low hormones all round as it comes from the medulla where things like adrenaline is made, but will also contain cortex.
Most late AF'ers have an adrenaline overdrive, which is why full glandulars arent recommended initially, once the system is calmed (which cortext glndulars can be used to help stabalise)
Thorne Adrenal Cortex is a good product if its right for you at the stage you are at. Start low - break the caps open and do 1/4 doses to check tolerance. If it stimulates , then its too much, if it calms then its the right amount.