Smoking and vaping don't affect your eligibility to donate. Become a donor and give life today. 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 Cannabis Use and Blood Donation: Unmasking the Truth Can You Donate Plasma If You Smoke Marijuana? 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