Do not donate blood, if you agree to have labs done on your bloodwork, seek to have done in doctor's office or by local hospital lab vs. big companies, but avoid if it all possible. find doctors who will treat you clinically vs. having to constantly check bloodwork.

Do not donate your organs. If you know someone and want to donate marrow or a kidney to them, that is your choice and you KNOW who you are helping and that it is legit. Same with donating blood directly to a relative or friend who is in the hospital.

Otherwise, starve them out and don't risk your blood/organs being used in rituals or drank by evil people for purposes used against you, your kind, or to assist evil people in extending their life/health, or for other evil abominations.