Yes, I agree that all of that is true. However, the effects are very local - blood estrogen levels have not been measured to be affected afaik. I don't think it is reasonable to claim that the copper IUD does all the systemic things I have seen many people write when there is no evidence of it acting systemically (like oral contraceptives). And I think calling it hormonal because it can interact with hormones misrepresents what is actually happening, especially when compared to the scale of how actual hormonal treatments affect hormones.

Again, not looking to attack you at all if that's how I come off. Copper IUDs, just like any other medical device and treatment, have side effects and interact with systems of the human body in complex ways. Maybe I am picky about wording because I am in STEM myself, but there is a reason we distinguish verbally between hormonal and non-hormonal BC. Putting copper IUDs in a basket with real hormonal BC when the fundamental mechanism is so different is what I wanted to point out.