As pointed out by IIIIIIIIIIIIIII, antibodies are way too massive and are not excreted in any significant amount (again, I am talking of normal physiology, not

As pointed out by IIIIIIIIIIIIIII, antibodies are way too massive and are not excreted in any significant amount (again, I am talking of normal physiology, not someone with very advanced kidney disease). To give you an idea of the weight difference, an average human IgG[1] antibody is about 500 more massive than a pretty average small molecule antibiotic like levofloxacin[2] [1]: https://en.wikipedia.org/wiki/Immunoglobulin_G https://en.wikipedia.org/wiki/Immunoglobulin_G [2]: https://en.wikipedia.org/wiki/Levofloxacin https://en.wikipedia.org/wiki/Levofloxacin