Can Cannabis Users Donate Blood?

Published on June 14, 2016 · Last updated July 28, 2020

The cannabis community is typically a generous bunch that loves to share (for proof, witness the altruistic glory of the communal bong). However, there's more than one way to demonstrate goodwill towards your fellow man. Every year, on June 14th, countries around the world celebrate World Blood Donor Day. This year’s theme is "Blood connects us all." The campaign aims to focus on thanking blood donors and highlighting the dimension of "sharing" and "connection" between blood donors and patients.

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Transfusion of blood and blood products helps save millions of lives every year. It can help patients suffering from life-threatening conditions live longer and with higher quality of life, and supports complex medical and surgical procedures. The annual event serves to thank voluntary, unpaid blood donors for their life-saving gifts of blood and to raise awareness of the need for regular blood donations to ensure the quality, safety, and availability of blood and blood products for patients in need. Here at Leafly, we’d like to encourage anyone who has the opportunity to get out there and do their part by donating blood if they can.

If you're a regular cannabis user, you may have wondered whether marijuana consumers can donate blood. In short, the answer is yes. To get a definitive answer, not only did we parse through various informational blood donor sites, we also reached out to local blood banks and the American Red Cross via email to get confirmation. We contacted three local Washington state blood donation companies to get their perspective: Bloodworks Northwest, Cascade Regional Blood Services, and Biomat USA. All responded very quickly.

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Here's the email we sent out:

I am writing an informational article for and wanted to get some information regarding cannabis and blood donation as June 14th is World Blood Donor Day. Do you test for THC? If so, does the presence of THC make someone ineligible to give blood? What advice can you give a cannabis user who would like to make a donation?

These are the responses we received from Bloodworks Northwest, Cascade Regional Blood Services, and Biomat USA:

Cannabis use does not affect a person's ability to be a blood donor unless they are assessed to be under the influence as determined during the donor screening process. We cannot accept blood from anyone who is intoxicated with alcohol, cannabis, or prescription drugs because of the possibility of an unreliable history and the inability to give consent for the draw. The FDA does not require testing for THC either at registration or during testing for blood borne pathogens which all donated/collected blood receives. – Bloodworks Northwest

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Blood Banks do not test for THC. Unfortunately, I cannot provide any advice to give a cannabis user who would like to make a donation. Sorry I could not help you more. – Cascade Regional Blood Service

Your blood will be tested for your blood type and infectious disease markers (including Hepatitis and Human Immunodeficiency Virus or HIV). These screening tests are to evaluate donor suitability and are not formal diagnostic tests. In addition, other tests may be performed based on your medical history or special testing required to qualify your plasma donation. Donors are also screened for syphilis, hematocrit, and protein levels. – Biomat USA

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All of these replies are pretty straightforward in confirming that there is no required testing for THC, but we felt we needed to cast our net a little wider. The American Red Cross is the largest single supplier of blood and blood products in the United States, collecting and processing approximately 40 percent of the blood supply and distributing it to about 2,600 hospitals and transfusion centers nationwide. Reinforcing what we’ve already learned, they provide guidance in their informative Common Questions about Donating Blood pamphlet:

While the Red Cross does not encourage the use of controlled substances, marijuana or alcohol use does not necessarily disqualify you from giving blood as long as you are feeling well. If you have EVER injected any illegal drugs, you can never give blood. – American Red Cross

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Never let it be said that we at Leafly don’t go that extra mile for our users. Not totally satisfied with this, we reached out directly to the American Red Cross with the same question we’d previously asked. This is the answer we received:

The American Red Cross does not test for THC. Under the current medical eligibility policy set by the U.S. Food and Drug Administration for blood donation, individuals who are currently under the influence of licit or illicit drugs or alcohol are not accepted for donation. Legal or illegal use of marijuana is not otherwise a cause for blood donation deferral. It is important that individuals do not present to donate under licit or illicit drugs or alcohol. Presenting donors must be generally healthy and feeling well at the time of donation. Potential donors should get a good night’s sleep, eat a good meal and drink plenty of fluids at least two hours prior to donating. – American Red Cross

You can take “feeling well” as a euphemism for “not being high.” If you are not “under the influence” of marijuana at the time of donation, it means that the psychoactive THC compounds in your blood have already been broken down. Your body metabolizes THC into two different chemicals; 11-OH-THC and 11-nor-9-Carboxy-THC. This process happens relatively quickly. Enzymes in the liver continue metabolizing these chemicals and transforms the psychoactive 11-OH-THC into 11-nor-9-Carboxy-THC which is non-psychoactive. This takes several hours ,and by the time that there is no THC or 11-OH-THC in your system, you are no longer high. So, when a blood bank states that your donation will not be accepted if the staff believe you have recently consumed cannabis, they are simply making sure that your body has broken down any psychoactive chemicals that your blood may contain.

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In a nutshell, as long as you don’t turn up baked, cannabis users are perfectly eligible to donate. You needn’t worry about any shark-eyed FDA enforcers jumping out from behind a curtain ready to nab you for allegorically spoiling the water-hole. That being said, you should be prepared for a mild, perfunctory screening process on the day of donation. You will have to answer some questions about your health history and places you have traveled to recently. You will also receive a mini-physical; the blood bank will take your blood pressure, temperature, and a small sample of your blood to test your iron level. The best advice that we at Leafly can give prospective donors is to turn up on the day well rested, having eaten a hearty meal, drank plenty of water, and to avoid caffeine, alcohol, and marijuana prior to donating.

Interestingly, we learned from our correspondence that the summer months can be particularly challenging for blood donations as vacation plans and seasonal activities often cause donors to be less available to give. According to the American Red Cross, this seasonal challenge can be overcome if at least two more people above what’s expected come out to give blood at each drive this summer. Leafly lovers, this is the time to make the effort. Your blood donation alone could save up to three lives. So, lay off the communal bong for one evening, encourage those other bong-hitting heroes to come along with you, and hit up your local blood bank.

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Ross Scully
Ross Scully
Ross hails from the west coast of Ireland but currently resides in Seattle, where he is a product manager for Leafly.
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