ic - brother, test 500 !?! Thats sick. I think in that specific case your pip was because it IS test 500! Not because of the blend. too high of a mg concentration of T per cc!
I thought T concentrations only go up to 400, they make 500?! Is it even physically possible to stuff 500 mgs of T into 1 cc?!
Personally, like i said above, i place my vials next to each others, i draw up in a 5cc syringe the compounds im working with, be it T , NPP, Masteron,... they all end up in the 5cc syringe, so yes its a blend created MANUALLY. I pulled each compound out of its own vial hence i know the exact mgs and i control how much to pull without affecting other compounds. Eventually im pushing a blend into my body, but its the HOW and HOW MUCH that makes all the difference. At least imo.
But def like IC said, some folks dont tolerate blends 'cause of pip or other various reasons, so if you're one, steer clear. "Hey doc, it hurts when i do this", doc = "dont do this".