here's what i've found so far. hope somebody else can chime in.
RPC is Radient pharmaceuticals Corp and is a publicly traded company within the US. Masteron is no longer sold in the US by any "human grade" producer. There is also a Radiant pharmaceutical conglomerate out of bangladesh but there product description doesnt have a masteron product. unless theres a UGL out there with this name i'd say it looks shady. You know anyone with experience with this particular manufacturer?