Arimistane is still legal, but it was removed from the profile for Alphamax XT and replaced with an improved ingredient profile. Many users were having issues with joint tightness and pain, which is a common side effect of Arimistane. Because of this, Alphamax XT was reformulated and improved to reduce the joint pain side effect. The new profile has more studied ingredients for natural testosterone increase and reduced cortisol and estrogen levels, and all of the feedback so far has been phenomenal. I am enjoying Alphamax XT more than the OG version, and not having to deal with pain in my elbows from the Arimistane has been great!
There are still some products that contain Arimistane. I don't know of any off the top of my head since I typically avoid Arimistane due to its side effects, but I'm sure others can help you out with that. Is there any particular reason you're interested in Arimistane specifically?