Severe bleeding linked to synthetic cannabinoid use Texas Poison Center Network 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 Can You Donate Blood if You Smoke Weed? Yeah, Bro! Smoking or Vaping Cannabis and Cardiovascular Function: Is 9Tetrahydrocannabinol the Main Culprit? Journal of the American Heart Association Smoking weed and plasma donation: are you eligible? Marijuana and blood donation what you need to remember?