Medically Reviewed by
Jason Crawford

Article Last Updated on January 10, 2023

Blood transfusions have saved millions of lives thanks to the generosity of millions of volunteers across the world. There are people who have donated blood multiple times before, and others who are thinking about donating for the first time.

Whatever the case, in order to donate blood, you have to be eligible and meet all the requirements needed. However, many marijuana users who want to donate blood are often left wondering if using weed disqualifies them from being a blood donor and if their blood sample will be checked for the presence of THC before being added to the blood supply. 

These are all valid questions that we will clear up in this article, so if you’ve been wondering about whether you can donate blood if you smoke weed, keep reading.

Your Eligibility as a Potential Donor

There are certain qualifications that make you eligible for becoming a blood donor, regardless of whether you’re a cannabis user or not. These are some general requirements that everyone has to meet and they apply in most blood donation centers. 

  • First, you have to be over 17 in order to donate whole blood. Some states allow it at 16, but in this case you’ll need to submit parental consent;
  • You have to be in general good health at the time of donation. If you’re feeling under the weather to the extent where it’s hard to carry out your daily routine, it’s better to skip it for the time being;
  • You have to weight at least 110 lbs;
  • If you have previously donated blood, there has to be an interval of at least 56 days between the blood donations.

Apart from these requirements, there are certain disqualifiers that will make you ineligible for blood donation. These include having certain medical conditions, blood clotting disorders, anemia, taking certain medications, etc. You can find a more detailed list of this on the American Red Cross website.

Cannabis Use and Donating Blood – Can I Donate Blood If I Smoke Weed?

If you’re a cannabis user, but want to donate blood, it’s normal to be concerned about cannabis being a reason for deferral. As you know, many workplaces do regular drug screens to detect illegal drug use, and cannabis is on the list because it’s still federally illegal. 

In fact, THC is the problem because it’s psychoactive and it lingers in the body for a long time, which is why it’s so easily detected. On the other hand, CBD is not problematic because it’s not intoxicating, so if you’ve taken CBD oil, you have nothing to worry about. THC, on the other hand, will be present in your blood for 3 to 25 days (or longer) depending on how much you’ve smoked, how frequently you smoke, your BMI, and so on.

So, while it’s true that the presence of THC in your system might make you fail a drug test, it doesn’t necessarily disqualify you from being a blood donor, as long as you meet the other qualifications. 

No Restrictions on Marijuana Use

Here’s a fact – it’s the U.S. Food and Drug Administration (FDA) that manages the eligibility requirements for blood donors and not the U.S. Drug Enforcement Administration. That being said, the FDA has not issued any requirements for the blood donations to be checked for the presence of THC. It appears that this dilemma is very common among cannabis users, so even the FAQ section on the American Red Cross website confirms this

One exception to this rule is consuming synthetic cannabinoids as “there are concerns that some varieties of non-prescription synthetic marijuana have been found to contain certain anticoagulants known to contaminate plasma.” The American Red Cross states that the FDA hasn’t issued universal guidelines regarding accepting blood donations from persons who use synthetic cannabinoids. The consensus is that each blood donation center should make an independent decision.

How to Prepare For Blood Donation and What to Expect

The whole process of donating blood takes about an hour and a half with the waiting time, filling in the forms, and the medical check-up included. If it’s your first time, make sure you’re well-rested and have a water bottle with you, just in case you’re nervous.

Once you get to your local blood bank, you will be asked to register by showing your ID. Then, you will talk to a designated medical professional about your medical history and whether you’ve traveled anywhere in the last few months. Next, you will get your blood pressure taken and your vital signs checked before you go through with your blood donation.

The process lasts no more than 20 minutes during which time you sit comfortably while the blood draws from your vein. When the process is over, you’ll be given some snacks and beverages for refreshment and you’re free to go home.

Don’t Go There While Under the Influence 

Okay, so donating blood is a very noble deed, but if you happen to be high and spot a blood drive, don’t just go there on a whim. You might feel fine and all, but if the staff notices you’re under the influence, you might be asked to come back again when you’re sober. The reason for this is that they need your sober consent and your signature, which is why you can’t just show up high (however much you mean well). If you’re a daily user, you should wait at least until the effects have worn off and only then head to the blood donation company. 

The Takeaway

There are certain qualifications you have to meet in order to become a blood donor and as long as you meet them, marijuana use is not an issue. Even though cannabis is screened for in drug tests because it’s still technically illegal, it isn’t a cause of deferral for donating blood.

Additionally, the American Red Cross has made it clear that being a cannabis user doesn’t disqualify you from donating blood, as long as you’re not taking synthetic cannabinoids or show up to your appointment under the influence.

A passionate advocate for the benefits of cannabis. Fraser Horton, who has a background in botany and a strong love of nature, has spent years researching how cannabis affects the body and mind. He established Leaf Nation in 2020, where he has devoted himself to educating people about the legalisation of marijuana and its safe and responsible use. Fraser is committed to highlighting cannabis’ potential for improving wellness and working to dispel the stigma associated with its use.


The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.