Masteron vs. Primo: everyone gets it backwards. People call Primo the perfect anabolic, but it actually lowers estrogen, which hurts your IGF-1 production (aka the whole reason you’re using Test & GH). Masteron, on the other hand, doesn’t convert to DHT or estrogen. All around, it’s just far more effective. Masteron > Primo, simple as that. Watch the entire breakdown on my YouTube, link in story. | Todd Lee Ifbb Pro