TRT and growth hormone have a synergistic effect. I would suggest you go with both. As well Sermorelin, is one of the weakest GHRHs. It has a very short 1/2 life of about 3 minutes. 3rd Generation GHRHs like modified GRF 1-29 have a longer half life of about 30 minutes. It is also recommended that you add a GHRP becasuse combined you get a much more synergism. In other words the efect on GH/IGF-1 levels is much greater.
500mcg/dose? From all the research I have read on doseing peptides the receptor site saturation dose is 1mcg/kg. Any more after that results in the law of deminishing results, very quickly. But simple math says 500mcg will get you 4 doses from a 2mg (2000mcg) vial. Is oral Sermorelin effective? Caveat emptor - Mayo Clinic reports that Sermorelin is only effective as an injection.