Can You Donate Blood if You Smoke Weed?

Blood donation and weed

Did you know millions of Canadians and Americans need a blood transfusion each year? That amounts to someone needing blood every 2 seconds. A standard donation is about 450 ml, or 1/10 of the total amount of blood of an adult.

One pint of blood (525 ml to be exact) can save up to three lives.

Blood banks also welcome plasma donations. Blood plasma is the liquid part in the blood that carries proteins and cells throughout the body. For medical purposes, it’s used for treating trauma and severe bleeding.

And since you’re here, reading our article, you must be wondering if you’re eligible to donate blood if you smoke weed. Or plasma.

Well, first of all, we’d like to thank you for considering donating blood and helping those in need. Secondly, the answer to both questions above is YES.

Perhaps the most common question that pops into the mind of an avid marijuana user is whether blood is tested for THC, the psychoactive compound found in weed. No, donated blood is never tested for THC, though it’s good to know that it can be detected in urine for up to 90 days from ingestion.

It doesn’t really matter if you smoke, drink or eat ganja, or use it as a topical cream prior to donating blood. Cannabis usage does not disqualify you as a donor.

If you smoked 24 hours before donating, well, it’s up to you to decide. It comes down to you being able to think and act clearly.

Now let’s take a look at what Canadian Blood Services and American Red Cross have to say about donating blood and plasma when using weed.

CBS: Recent donation criteria changes

Canadian Blood Services regularly revises the criteria for blood donors based on scientific evidence. Last year they released an important update for marijuana lovers:

Marijuana and alcohol – If you are sober, show no evidence of intoxication and can give an informed consent, you are eligible to donate. Prior to these changes, donors had to wait 12 hours after the resolution of intoxication. Many people believe that they are deferred because of past marijuana use, but that is not the case.

Basically, if you pass all other criteria, the only thing they’re asking for is for you to be able to give informed consent. Otherwise, if you’re too high, you might not be able to give your medical history details either.

American Red Cross

Although we couldn’t find anything official about donating blood when using cannabis on the American Red Cross website, they issued a statement to an online health information site called Healthline. Here’s where they stand on the subject:

“While the Red Cross does not encourage the use of controlled substances, marijuana, cigarettes or alcohol use does not necessarily disqualify a person from giving blood. Potential donors cannot give while under the influence of licit or illicit drugs or alcohol. Legal or illegal use of marijuana is not otherwise a cause of deferral.”

So, it’s a ‘yes’ from Red Cross as well.

We’re through to the next round!

Should you donate blood if you use cannabis?

If you feel like it, do it! But just in case you’re still unsure, we have a list of 8 super-duper reasons to donate:

  • It’s a selfless act and you get to be a hero.
  • It could make you live longer.
  • You or a loved one may need a blood donation in the future.
  • You get a free, mini check-up.
  • You will burn up to 650 calories per pint of blood donated! 
  • It’s free.
  • One hour of your time may save someone’s lifetime.
  • You’ll get a cookie and a juice box. 

That last one got you, admit it.

Blood donor eligibility criteria

Each blood donor has to meet the eligibility criteria in order to donate blood.

The basic requirements for first-time donors are: you must be over 17 years of age and weigh at least 55 kg, you have to be in good shape (perform usual day-to-day activities) and be healthy overall.

You can always take an online eligibility quiz at the Canadian Blood Services’ site. It takes about two minutes and you’ll find out whether you’re able to donate.

If you’ve donated blood before, it’s good to know you have to take a break in-between draws. Blood can be donated every 56 days (for men) or 84 days (for women). On the other hand, you can donate plasma every seven days.

What can stand in the way of you being a hero?

There are a handful of factors that can make you ineligible for donating. We’re going to name a few:

Wellness – If you have a cold or flu symptoms such as a sore throat, fever, headache, or muscle ache, you should wait until you get well to give blood. In fact, it’s advised to wait at least 48 hours after the symptoms dissipate before you donate.

Travelling – Visiting countries outside Canada, continental U.S. or Europe may expose you to foreign infections. You may not feel any symptoms, but your blood might be another story. You could easily transmit the infection through your blood, which is why there’s a screening process to rule out any possibilities.

Donors usually have to wait 21 days after they return home to donate blood. And in case your stay in a high-risk country was longer than 6 months, you could wait up to 3 years.

Lifestyle – Recent changes to eligibility criteria also include changes to the section on tattoos. You no longer have to wait six months after getting a tattoo to donate. The temporary deferral period is now 3 months.

Sexual preferences – If you’re a gentleman who’s had sex with another gentleman, you’ll have to wait three months to donate (compared to one year waiting period before the changes).

Dental works – Depending on whether you’ve had your teeth cleaned or a tooth extracted, you have to wait either a day or 72 hours.

Medication – Most prescription medications will not prevent you from donating, but in some cases, you’ll have to wait after completing your treatment.

Iron – All donors are advised to follow an iron-rich diet. If you’re a frequent donor, ask your doctor about iron stores deficiency and supplements. Taking multivitamins will not defer you from giving blood.

Period – If you’re having your period, you’re OK. You go, girl!

Vaccinations – You may be temporarily deferred if you’ve received a certain vaccine such as Varivax or Zostavax. For more information, please see the Vaccinations table.

In any case, final eligibility is determined by the staff at the donation centre.

Before you go to the nearest blood bank

We have prepared some advice for you before you visit the nearest Canadian Blood Services donor centre or Héma-Québec donor centre to donate your blood.

Make sure to prepare your body before donating:

  • Eat iron-rich food (beans, red meat, fish, spinach, etc.)
  • Drink plenty of water for at least two days before you go
  • Rest
  • Eat a healthy meal two hours before donating
  • Have a healthy snack and drink a bottle of water just before the donation

Cannabis use prior to donating is fine, especially for relaxation purposes, but make sure you don’t go overboard with the quantity

After you’ve done your good deed, you might feel a bit woozy. That happens because your blood pressure can drop. In order to avoid it, you should have plenty of water or sports drinks to rehydrate. They’re usually available at the site.

To restock yourself on nutrients after a blood draw, you should eat food rich in folic acid such as asparagus, orange juice or liver, to help create new red blood cells.

If you’re low on iron, make sure to have enough fish, meat, or nuts. You can also have some dairy products like milk or yogurt to speed up the process.

And don’t forget, no “heavy lifting” for 24 hours after your donation. You can go one day without exercising. Rest is equally important before and after donating.

Final thoughts

If we have, by any chance, convinced you to go to your nearest blood donation centre and check if you’re eligible, we’re very pleased.

Unfortunately, we can only give you a standing ovation from behind our screens and a virtual tap on the back. You’ll get your cookies there ☺

Let us know if you have any additional advice or if we’ve missed something. Support is always appreciated.

In the meantime, we want to thank all organizations that are constantly working on raising awareness on this subject and making efforts to improve donor experiences.

Remember, blood cannot be manufactured, it has to come from donors. That’s why it’s important to donate, even once a year, because every little bit counts!

About the author
Helena Miles

Experienced journalist with a decade-long experience of researching cannabis. She has been featured in many prominent outlets, such as The Growth Op, National Post and The Province.

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