Can I Donate Blood? Common Blood Donation and Eligibility Questions Can You Donate Plasma if You Smoke Marijuana? Smoking or Vaping Cannabis and Cardiovascular Function: Is 9Tetrahydrocannabinol the Main Culprit? Journal of the American Heart Association Did you know: You CAN donate blood if you use cannabis. If you have any questions about blood donation, please ask us! #DidYouKnowAboutBloodDonation Smoking (or vaping) doesn't affect your ability to donate blood. Help us bust this myth by sharing our post.