Furthermore, one company noted that “the FDA does not require testing for THC either at registration or during testing for blood borne pathogens which all donated/collected blood receives.” And the American Red Cross told them that “legal or illegal use of marijuana is not otherwise a cause for blood donation deferral.”
There are two questions here, really: “Can I donate blood if I smoke weed, in general,” and “Can I donate blood if I smoke weed that day.”
For now, the answer overall seems like a “yes.” But if you’re squeamish or anxious at the thought of getting lit before surrounding yourself with volunteer nurses, maybe chill on the J till after they’ve sucked you dry.
The short answer? Yes, you can still donate if you smoke.
The long answer? Yes, you can still donate, but it’s a little complicated.
Technically, injectable drugs are what blood drives are really on the lookout for, since those increase patients’ chances of contracting a serious bloodborne illness. But all blood is tested before its given to patients, so donating doesn’t automatically mean your blood will be used.
In 2016, Leafly went the extra mile and reached out to several blood donation companies to ask about cannabis use and donating. Everyone the publication contacted, including the American Red Cross, echoed the same: Being a general cannabis user will not prohibit you from donating, but you must be sober while physically making the donation.
According to the internet (and this writer’s doctor sister), there’s plenty of personal anecdotes (including from yours truly) about smoking and donating blood without running into any problems. Most people advise waiting a day after you’ve last smoked to donate, though there’s no real reason to wait unless you’re stoned at the time you’re intending to donate.
When you smoke, most of the cannabis (80-90%) is excreted within 5 days as hydroxylated and carboxylated metabolites. So if you’re a light smoker and wait a few days, there’s a good chance your blood will have very low-to-negligible cannabis levels. Even if you’re a heavy smoker, marijuana is absorbed mostly through your tissues, and excreted mainly through urine. While blood is the delivery method for all those tissues, what you’re imbibing is spending most of its time elsewhere in the blood or metabolizing in your blood.
Canadian Blood Services—which provides a complete list of criteria affecting eligibility for blood donation on its website—introduced these criteria in 2016 to identify donors at risk for acquiring illnesses spread by mosquitos, such as the Zika virus, which can cause birth defects. CBC News, reported two years ago that only about 3.4 percent of eligible donors give blood.
In addition to donating red blood cells, cannabis users are also eligible to donate plasma, the protein-rich liquid in blood that helps other blood components circulate throughout the body.
In its most recent annual report, Canadian Blood Services noted that in 2017-2018, 410,000 people visited donor centres, up about 1 percent from the previous year. Of these, 101,000 were new donors. In that same year, 730,841 red blood cell units and 30,374 litres of plasma for transfusion were transported to hospitals across the country.
“Many people believe that they are deferred because of past marijuana use, but that’s not the case,” says Ross FitzGerald, a strategic communications specialist with the Canadian Blood Services in Ottawa.
Three conditions, however, must be met, FtizGerald makes clear. “If a person is sober, shows no evidence of intoxication and can give consent, they are eligible to donate.” These rules are relatively recent. In April 2018, Canadian Blood Services removed a requirement that donors had to wait 12 hours after cannabis use before they could donate blood.
Those who have traveled to other countries, including the continental U.S. and Europe, have a waiting period of 21 days after returning home before they can donate blood.
Of course, there are a number of factors that will make a person ineligible to donate blood. Age is one of those factors. Donors must be at least 17 years old and meet minimum height and weight requirements. First-time donors up to 23 years of age must also meet specific height and weight restrictions, with anyone older than over 23 needing to weigh at least 50 kg. Residence or travel outside of Canada may also impose a temporary restriction on a would-be donor’s ability to donate blood when back in the country.
Canadian Blood Services, which has overseen blood collection in the country (except Quebec) since 1998, reports that plasma is used to treat trauma and severe bleeding as well as to make products such as immune globulin, used to treat a range of disorders, including autoimmune, neurological and blood disorders.
It’s well-known that blood is a lifeline—literally—for many Canadians. What is likely less well-known is whether or not people who use cannabis can donate blood to support that lifeline. Well, the answer is a resounding, “Yes.”
Can cannabis smoker's donate blood? Can you donate blood as a weed user? Here are the Red Cross blood donation rules