Good going, guy.
I give blood every so often...been doing it since I was in jr. high school.
It has the extra added benefit of letting you know if you're clean.
They test the small sample out.
Sometimes you even get the results back,
or you become a part of a study and you get those results. (this is very cool)
Just make sure, you've eaten...hopefully with some juice.
And that you have enough body mass to draw the required amount.
Actually the little pin prick for iron hurts more than the bigger needle. (it is nothing.)
They can do this with their eyes closed. (but don't
)
Give blood...it shows you care.