Fair question and for as much as I DO know, I’m the first to admit when I don’t know the answer to something as well.
I am not aware of any science in relation to why many have no issues with Hex over other esters.
I used Ace last year for my prep and had very little issues as well which I attribute to being in a deficit.
@Stewie @homonunculus or
@DOGGCRAPP may have a better explanation as they are far smarter than me on these subjects.
At the end of the day I agree with
@slesh - find what works best for you. Sometimes there isn’t a scientific answer in bodybuilding and other times bodybuilding contradicts science as most studies are done on “average” people.
I couldn't tell you either, but a few thing occur to me:
• Compare the other components of tren hex vs. acetate: Carrier oil, BA, BB contents. The carrier oil and perhaps even effects of the acetic acid vs. hexahydrobenzylcarbonic acid that is released could play a (small) role.
• The relative concentrations of tren of course and tren metabolites is going to be a function of the ester involved, i.e., how fast it's release from the depot and presented to the liver where various metabolites can be produced (whole lot of them:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7251174/) Spitballing here, but the relative serum metabolite concentration as a function of the rate of presenting the parent compound (tren) for metabolic breakdown could play a role (but I don't know if / which of these metabolites have relative activity that could bring this about.)
• Of course if you're off-season vs. dieting / in a deficit, the differenced in the other PEDs you're using could very well interact, in a multitude of ways. Also, competition among CYP enzymes among the AAS, as well as Phase II enzymes in the liver could / would be different depending on what other AAS are in the mix.
• Relative amount of tren in acetate vs. hex., of course at a given mg dose of the compound.
• Bunk stuff... LOL
In other words, to what extent the various components of a PED cocktail have desired vs. undesired effects will depend on what else is in the cocktail. Tren acetate and Tren hex have different pharmacokinetics b/c of the ester differences which can thus affect the overall pharmacodynamic effects in general, and in particular the various effects (both good and bad) of the other components of the cocktail.
(Again, totally spitballing here!)
-S