Can You Give Blood If You Smoke Weed? Explained Clearly Smoking (or vaping) doesn't affect your ability to donate blood. Help us bust this myth by sharing our post. Can I Donate Blood? Blood Donor Eligibility Checker Bloodworks Can Marijuana Use Prevent You From Giving Blood? We all know smoking and vaping isn't great for your health. But it doesn't stop you from being a blood or plasma donor. Just make sure to wait one hour after donating Blood Donation While Using Medical Marijuana Dr. Green Relief Marijuana Doctors