Myth: You can't donate blood if you smoke or drink. Fact: Smoking or occasional drinking doesn't automatically disqualify you. But avoid alcohol for at least 24 hours before donating to Smoking (or vaping) doesn't affect your ability to donate blood. Help us bust this myth by sharing our post. Marijuana and blood donation what you need to remember? Medical Marijuana for Leukemia: 9 Things To Know MyLeukemiaTeam