Honestly it does,so does a coco husk and moss mix which I used last as well..but I'll be honest if u take the time when u have it to mess with your lamp set up,covering the screen etc,you can hold humidity just as well with aspen,my bigger guy just shed perfect and made a few adjustments to the lamp heat set up as well as the way I covered the tank and wett towels etc and he has aspen now..during his 5 days shed cycle,humidity never dropped below 65 and stayed mainly around 75-80.