Never tried but havent found one bad review. I personally take superpump so Im not buying anything till I run out. I do build a tolerance to this stuff so I have to cycle. Let me know what happens if you end up buying it. Alsoalot of people are saying dont take it past 3-4 or you wont be able to sleep.
check out these reviews
SUPPLEMENT CRITIC.COM - MRI BLACK POWDER REVIEWS