What is commonplace today would be considered synthetic decades ago. Look at the breed of plants we grow, animals we raise, and staple foods (cheese) we eat.
I think you’re right. I’ve eaten vegan most of my life and take creatine to make up for the lack of it in my diet with no downsides. It gives me a little more energy for workouts and runs. I don’t look bigger or bulkier, just feel a bit sharper.
I also understand the discomfort with the culture of “optimize everything” and constant self-experimentation. Supplements like creatine get framed as steps toward some perfect, engineered version of ourselves, and that framing feels like a hangover of eugenics thinking. It causes an acute, if subconscious, aversion that can manifest in the cool dismal of your parent's comment.
That unease matters. Maybe if we were more objective we would say it should not matter, but it does. And, while I often just ignore it, I am not sure I want to fully let go of it yet.
Different people have different body chemistries. For many people, these supplements can help provide something their body might lack or process differently than other people. In many ways, it's no different than drugs (like medications). The actual line is really just an artificial boundary put in place by regulatory bodies.
I know I've seen _major_ life improvements with the addition of a few key supplements.
Can't we just live as we are and not aim for some ideal only reachable through the use of synthetic substances?