I actually donate a lot, bout every two months for whole blood. I do it all the time so afterwards I feel no difference, maybe a sore arm if the phlebotomist wasn’t the best. If you go in with an empty stomach you might feel crappy and if you go in dehydrated they’ll struggle getting the blood… and you’ll feel pretty crappy.

I do it mostly for the civic duty of it all. Better to help when you can imo. Also there is a ton of data about donating blood being good for you. I’ve seen articles on it helping remove micro plastics and PFAS chemicals from the body. So hey, might as well