Well since he gave it to you out of a 50ml bottle, just shoot some in your ass, wait about 24hrs & see how large of a knot you've got on your ass. If it hurts to sit down, you got the right stuff! LOL The 50ml has a higher BA content & causes pain (in some people) it's been tearing me up for the past 6 weeks. If you trust him & have done business with him before, all I can say is try it & see if it works. That shit is dirt cheap so, I'd have to say it really wouldn't be worth even trying to fake it. If I were you though, I'd be looking for a higher quality source for future use. Personally, I would probably just pass it on to someone who wouldn't mind using it & go to another source. I never mess with shady people like that, if there is any question about something I'm going to inject, I wont use it but, hey, that's just me, I give a shit about my health. Just my $.02