enanthate or cypionate are simple T esters that yield bio-identical T
all T is synthetic as in man made
IM vs subq is not really part of this distinction, but I strongly always suggest subq, twice a week and AI dosed at the same time. hCG 250iu SC/SQ EOD prevents testicular damage and preserves fertility. How old are you...
"my thyroid function is fine": You cannot state that thyroid is good based on almost all thyroid labs, that is why I ask that you eval via oral body temps as suggested above.