I don't use one, but then again I truly never come off since I am on TRT. My body pretty much no longer produces testosterone so I have to get shots in my rear 2X a week for the rest of my life!
This does have an advantage though as I don't ever have the true crash of testosterone. With that though my test is pretty expensive as I have a script that my work pharmacy will not cover, yet. Hopefully I will get things changed in the future, but it is going to be a battle with doctors and insurance companies.