I have never tried
Vitrix: it is too expensive. I would like to though.
Endotest is far more resonably priced. I took 3 per day as a max dose, and had good results. I cannot defin itively say it raised my test levels because I was not tested. It does something, though, for sure: I get better pumps in the gym, libido goes up, I get acne a bit, i just feel good...Consistent with raised test levels.
SAN Tribuvar is good and cheap, but not as strong as
Endotest. Stay away from other tribs, like Optimum: cheap ones do nothing in my experience.
I would also try Sopharmas trib: it is the original Bulgarian product, and I hear it is very good.