Donating blood saves lives. Patients who have experienced serious injuries, surgeries, anemia, cancer, blood disorders, childbirth and other circumstances can survive because of blood transfusions.  The amount of blood needed for transfusions is astounding, according to the Red Cross, someone needs blood every two seconds, but less than 38 percent of the US population is eligible to donate.  If you are healthy and meet all of blood donor eligibility guidelines, but you consume cannabis, can you still donate?  The short answer is yes, cannabis consumption does not immediately disqualify you from making blood donations.   However it should be noted that the Indiana State Department of Health (ISDH) is recommending that those who have used synthetic versions of cannabis to not donate blood or plasma.  Those who use synthetic versions of cannabis do run a significant risk as the drug can contain  long-acting anticoagulants and those who consume it are at risk of severe continued bleeding. Synthetic cannabinoids are known to be contaminated with brodifacoum, a lethal anticoagulant commonly used as a rodenticide. 

Source: iStock

Do Blood Banks Test for THC? 

Blood banks do not routinely test for THC, tobacco, or nicotine. However there are two caveats; 

1. If a potential donor is visibly high, it is likely that they will be turned away. Blood banks will not take blood from potential donors who are under the influence of legal or illegal drugs or alcohol. The primary reason for this is consent. Blood banks cannot obtain legitimate consent from an intoxicated person. 
2. Blood collection centers could elect to screen blood donors for the use of synthetic cannabinoids, due to the above mentioned bleeding risk particularly if they are concerned about the prevalence of use of such synthetics.

What is Blood Tested For? 

After blood is taken, it’s processed and separated into red cells, platelets, and plasma. The red cells and platelets are stripped of white blood cells to reduce the risk of adverse reaction in the recipient.  It’s then screened for certain infections including: 

• Hepatitis B virus 
• Hepatitis C virus 
• HIV
• HTLV
• Syphilis
• West Nile Virus 
• Zika Virus 
• Bacterial contamination 
• Babesia
• Chagas disease
• Cytomegalovirus  

The Effect of Cannabinoids on Donations 

Cannabinoids enter the bloodstream within 3-8 minutes after they are inhaled and 2-3 hours after they are ingested. While the cannabinoids are drawn to fatty tissue from the bloodstream, they remain detectable in the blood of heavy cannabis users for up to 60 hours. While it is clear that cannabinoids are found in the blood in the hours after cannabis use, it is not clear if this impacts the quality of blood donations.  A 2019 Transplant International: Official Journal of the European Society for Organ Transplantation conducted a review of the evidence on the impact of alcohol and drugs including cannabis on donor hearts and lungs. The United Kingdom-based research team found that, while a risk worthy of investigation, cannabis use wouldn’t prevent a heart transplant. While this review does not specifically examine the effect of cannabinoids on blood donations, its results support the stance of most blood blanks: natural cannabis consumption does not disqualify a potential donor for giving blood. More research is needed to understand the impact of cannabinoids on donor blood and organs. 

General Rules for Donating Blood

If you are interested in donating blood, platelets, or plasma, you will likely need to abide by the following rules:

• You should be healthy. If you are taking antibiotics, have a fever, or are producing phlegm, you should wait to donate.  
• You should be the appropriate age. Most states allow people who are 16 and older to donate whole blood. The age guidelines vary by state depending on whether you want to donate platelets or plasma. 
• You should be the appropriate weight and height. A person’s blood volume depends on these numbers. Too little blood volume may make it difficult for someone to tolerate the quantity of blood lost during a donation. To donate blood, you should be at least 110 pounds. There is no upper limit outside of the weight limit of the donor bed. 

Travel Rules 

If you have traveled out of the United States to a malaria-risk country, you should wait to donate blood. The Red Cross recommends waiting 3 years before donating blood if you contracted malaria and completed treatment for it.  You should wait at least one year if you've visited a malaria-risk country. If you've lived for over five years in a country that has had known malaria cases, you should wait one year before donating blood. 

Joon Airbus A321-200 taking off. Source: iStock

Disease Rules 

Your eligibility may be affected if you have any of the following diseases: 

• Zika 
• Ebola 
• Bleeding conditions that disrupt normal blood clotting
• Certain cancers like leukemia and lymphoma
• Heart disease 
• Hemochromatosis 
• Anemia
• Hepatitis
• Jaundice
• HIV, AIDS
• Fever or infection
• Malaria
• Sickle cell disease 

If you have a disease, talk to your doctor and the blood bank before donating blood. 

Medication Rules 

Donation eligibility is not affected by most medications. However, if you are taking any of the following medicines, you may need to wait before donating:

• Blood thinners. These drugs will not allow your blood to clot normally, so you should not donate. If you stop using these medications, you must wait 7 days after your last dose. 
• Hepatitis B immune globulin. This therapy is given after exposure to hepatitis. You must wait 1 year to donate blood after being exposed to hepatitis. 
• Human pituitary-derived growth hormone. If you have ever used this therapy, you may not donate blood. 
• Thalidomide. You must wait 1 month to donate. 
• Mycophenolate mofetil. Wait 6 weeks. 
• Acitretin. Wait 3 years. 
• Etretinate. You are ineligible to donate blood if you have ever taken this therapy. 
• Arava, Erivedge, Odomzo. Wait 2 years. 
• Aubagio. Wait 2 years. 

If you are unsure about your eligibility, contact the blood donor directly. 

What Can You Do If You Can’t Donate Blood? 

Donating blood can save lives, and the emotional reward of giving is great. Although cannabis consumption will not automatically disqualify you from donating, you may be ineligible for other reasons.  If you are unable to donate blood, here are a few ways that you can still help: 

• Volunteer at a blood drive. 
• Host a blood drive. 
• Encourage eligible donors to donate their blood.
• Help someone donate. Accompany a nervous friend, offer a ride, or provide childcare for the duration of the donation. 
• Donate money to a non-profit blood blank.