The absorption rate. I got a really cheap home brew and I don't want to waste expensive or scarce powders trying to see if it works.
Some people get a metallic taste in their mouth when they apply 1-Testosterone, unfortunately I'm not one of them.
I've considered DHEA, but I don't think it would be noticeable enough to tell.
I'll probably end up tossing it and ordering the new penetrate, but it seems like there must be some easy way to test it.