Brings up an interesting question. Say you couldn't donate due to tattoos, needle use from steroids or IV drugs ("have you ever injected anything not prescribed by a doctor"), gay or paid sex, etc
Are there services for bloodletting?
It’s not bloodletting but some things do come out in sweat, I remember reading a paper that demonstrated heavy metals come out in sweat in significant amounts. Perhaps other things do as well.
That would mean people who workout a lot should have less than sedatary people.
This is quite possible, now go write a grant application for a study :)
Or cultures that use the sauna.
During blood donations there's a step where they ask you if it's okay to use your blood (which is indicated by selecting one of two barcode stickers that the technician can't interpret). I assume this is for people who are pressured to donate blood as a group but don't want to out themselves as being ineligible. You could just go do that and select the "don't use my blood" sticker.
Oh wow. I didn’t know that and I’ve had to come up with some lame excuses in the past.
So even the tech can’t see that it’ll ultimately be disposed of?
Correct, you take one sticker and place it on the form you're filling out, and place the other somewhere else, I forget where. So when the tech turns around they can't know which one you picked.
Yes.. "Venesection." People with hemachromatosis utilize it.