Why are you not taking oral HRT if you're doing the "online" route? I spent the last five years being on and off self-medicated HRT, so I don't feel like it's my place to sit here and tell you that the only option is to get a prescription, but injecting anything that you do not know is absolutely legitimate is just about as risky as you can get. Unlike pills where, under a lot of circumstances, something not legitimate might make you sick but probably wont kill you, injecting something that isn't legitimate could EASILY end your life.
I wouldn't inject ANYTHING purchased on some website into my body, and I just pray that, if you do decide to self-medicate, that you chose something other than injections.