Meno, did you see the reference above in Yechaveh Daas 3,84 from Rav Ovadya Yosef ztz’l?
No. Does he say you’re allowed to donate 2 kidneys?
(Just to explain, I was making a joke. Ubiquitin said that he was unaware of anything that a kidney donor should avoid. I was responding that kidney donors should avoid donating a kidney, because then they will have donated two kidneys, which is not advisable.)