this is waht i can tell you from personal experience..
I got good results for years off the animal grade gear...
i then tried human grade testoviron...it was like doing my first cycle all over again, i grew faster and bigger then i had on the animal grade in years..
I then tried gear that came from a friend who made it and again i got great results...
in short i woudl say that most 80-90% of all mexican or any other stuff is under dosed alot more then we are giving them credit for..if i had too guess i woudl say a bottle of test that says 250mgs is probley more like 175-190mgs..just my opinion and i have no data to back that up but the few things i did have experience with and the feedback i got from others woudl lead me to this opinion...
Example is the EQ out there..i tried brovel,QV,SYD,Ilium,Jurox and Ttokkyo and got modest results over the last 10 years...when i tried the Denkall Ultragan-100 i got awesome results nothing like i ever got from the others..so you never why some work and some don't unless you have everything tested or you make it yourself...