From multiple very reliable sources I've been told they've never seen a fake Karachi sust, because theyre so damn cheap (price wise...not quality) in the first place & large quantities blah blah blah. You wont be dissapointed with em
Just finished my last karachi sust amp a couple of weeks ago. I thought that they worked very well. I ran it with some d-bol and some yellow top deca, that I think were fake as hell. I didn't get the usual bloat from the deca that I usually got so I think that they were fake.