I like the question is anabolic steroid use against Gods will.
I would argue yes it is. Steroids improve physical performance and appearance aka vanity. At the same time, God says what we put into our bodies does affect our "temple".
Vanity can cause one to become prideful and impressed solely with their appearance and their acheivements etc.
I know for decades I abused steroids. I would also argue that it is a mental health issue, a body dysmorphia. An addiction of some sorts.
Would God be upset with addiction and mental health issues? That's a great topic. Many people believe addictions to be demonic attributes or a demonic presence. Many of us have struggled with addictions and will readily admit how terrible and awful and difficult they can be to overcome.
I don't use steroids anymore, but I abused them for 2 decades at least. But now I am on prescribed HRT. Lets be honest, that's still sterorids even if low dose. Even if my body now "needs" it, it derived from my abuse over years and years. Like many drugs people will say "they did it to themselves". I absolutely did, but now should I suffer now that I messed up my body from my vanity and from my bad decision making? Will God be upset with me for this?
It's a moral and ethical question at the least. We all have sinned and come short of the glory of God, right? Satan was cast from heaven because of pride. So at the very least, the Christians using steroids must be very cautious not to stumble into pride and vanity. God forgives of all sin, but we must not assume just because that is true, we can sin when we want and do what we want, only to then ask for forgvieness.
It's a very very good question tbh. It would have good arguments on both side of the spectrum.
Does God feel I sin for using HRT even though I did it to myself? I think not. But I also am no longer looking in the mirror, pre-occupied with my appearance, muscle size and athletic performance either. Is bodybuilding a sin? Even the angels pursuits were to be bigger, stronger and faster, but within the scope of Gods will. My answer, I don't know. It would be a cool side topic, but I guarantee it would start alot of arguments between good members.