What are the known side effects to Donor when donating plasma?

Bruise where the needle goes in

Depending on if you have eaten right or not, You might feel fatigued or just pass out. My mom went to donate plasma and some girl that was there, who was also donating plasma, nearly passed out because she hadn't eaten right.
Make sure you eat a good meal before you go. It's not the same as donating blood, but you an still get queasy, lightheaded, or tired.