Timbaland's body is damn near unrecognizable from where he was a couple years ago -- and he's crediting his will power ... for keeping him in the gym, and off prescription pills.
Justin Timberlake's fave mega-producer was on "TMZ Live" Friday, rocking a muscle tee, no less, and showing off his brand new physique. Seriously ... the guy's looking ripped after losing more than 130 pounds.
Tim told us he knew he had to "hit the reset button" when he kept having dreams about how his body should look.