That’s a great point about higher test levels possibly leading to the body being in a sympathetic state more of the time than if that same person had lower test levels. Being in a parasympathetic state is extremely important for things like digestion and healing. So it would make sense that if higher test levels caused a person to be in a sympathetic state more of the time, healing in certain areas could be effected. Not all areas tho, I would assume. Since testosterone can increase healing/ regeneration in things like skin, muscle and bone.I think I mostly agree with you, but when you say normal levels shouldn't cause harm, how we define normal is important. For example, my baseline free T was about 11 ng/dl and then i sent it up over 20+ ng/dl with some cream and my stomach started acting up. I might still have been in the normal range (barely), but normal for who? Not normal for me if my body likes to sit at 11.
Talking about benefits for most people that certain vulnerable types can't handle, if testosterone increases gastric acid secretion like it did in those rats, that could explain some of the experiences we're having.
We know there are tradeoffs inherent with increased testosterone because otherwise we would have evolved to have more. Maybe it sends more amino acids to the skeletal muscles instead of repairing the gut, the way it depletes your iron stores by directing all of it to RBC production. Testosterone certainly cranks up some people into a wired state with elevated HR, BP, insomnia, etc that doesn't seem conducive to the parasympathetic rest & digest program that normally maintains gut health. Just spitballing random ideas here but you get the picture that something like this could be involved.
and that’s another great point in regards to the possibility of increased testosterone levels partitioning nutrients and resources differently/ using up certain nutrients more in order to increase some of the bodies actions, like how testosterone can cause iron stores to deplete faster since testosterone increases RBC production at a greater rate than men with lower testosterone levels. There absolutely could be trade offs to consider with testosterone, and like u said, everyone‘s body is going to function optimally at different levels.
But what matters most, imo, is anecdotal/ real world results. Clearly if u and @Belekas saw gastrointestinal issues when u raised ur test dosages, there’s definitely something going on here. The exact mechanism of action tho is hard to say. That study u posted at least offers a possible answer to what could be going on tho. So thanks for posting it