Can CBD Oil Cause You to Fail a Drug Test


Girl Looking Surprised

I recently had a question from someone who asked: “Will ingesting CBD oil show up on a drug test?”

The brief answer is no…the longer answer is “there is a possibility that you can fail a drug test by having CBD in your system if there is even the tiniest bit of evidence of THC in the CBD oil.”

Let’s review what CBD is and how it might affect a drug test.


In 1940, Cannabidiol, or CBD as it is commonly known, was discovered. It is a phytocannabinoid (cannabinoids that occur naturally in the cannabis plant) and accounts for up to 40% of the plant’s extract.

CBD is non-psychoactive and not responsible for creating a ‘high’ or euphoric state. It aids in treating a host of conditions including anxiety, cognition, movement disorders, pain, as well as epileptic seizures.

Cannabis that contains less than 0.3% THC) is hemp. If CBD is legal, what’s the problem? None, until it comes to operating a vehicle or if your employer is concerned.

CBD products can contain little to no THC in much larger quantities, and herein lies the issue.


THC (tetrahydrocannabinol) is a very well-known psychoactive component in cannabis (marijuana).


As of October 17, 2108, under Bill C-45, it is now legal for adults 18 or 19-year-old (depending on province or territory) to purchase it legally, grow it, and use a limited quantity of cannabis.

With this Bill comes stringent guidelines and penalties regarding the amount of THC that can cause impairment.

CBD is available everywhere; most are from reputable companies, but some are not. (Please note that CBD has the same regulations as cannabis, meaning producers must have a license to produce it and retailers must have a registration to sell it).

Many people when buying CBD products are told it has little or no THC in it. In fact, do you know that 70% of cannabidiol extracts sold online do not have the proper labels? Which brings us to the question, “Can you fail a drug test by ingesting CBD oil?” The answer? It depends on what’s in your CBD oil, or how much THC it contains!


Drug tests detect THC, not CBD. If the CBD oil you are taking has THC in it and you are operating a vehicle, this is what the Canadian Department of Justice has to say about THC:

If you have between 2 nanograms (ng) and 5 ng of THC per ml of blood, this is a minor offence. However, if you have 5 ng of THC or more per ml of blood, it is a more serious offence (a nanogram is one billionth of a gram).

Penalties vary depending on quantity, first time offence or repeat, or causing bodily harm or death to another person.

Having 5 ng or more of THC per ml of blood within 2 hours of driving can result in a mandatory minimum fine for the 1st offence of $1,000, 2nd offence mandatory minimum of 30 days imprisonment and 3rd offence mandatory minimum of 120 days imprisonment.

A combination of blood alcohol content of 50 mg per 100 ml blood and 2.5 ng or more of THC per 1 ml of blood within 2 hours of driving also includes the above mandatory minimum penalties as well as a maximum prison term of 10 years for a 1st, 2nd or 3rd offence; a refusal to be tested can result in a minimum fine of $2,000.

Having over 2ng but less than 5ng of THC per ml of blood within 2 hours of driving can result in a summary conviction (offences which include the least serious offences under the Criminal Code of Canada) of a $1,000 fine maximum.

Causing bodily harm can result in a summary conviction of 2 years maximum imprisonment less a day. An indictment (the most serious of criminal offences and can impose life imprisonment) can result in imprisonment of 14 years.

Man sitting in car


  • In 2017, there were almost 3,500 drug-impaired driving incidents reported by police (the information did not say how many were because of cannabis).

  • The percentage of Canadian drivers killed in vehicle crashes who test positive for *drugs is 40% and actually exceeds the 30% who test positive for alcohol (again, there was no breakdown on how many were cannabis-related).

*It is worth taking note here that cannabis (THC) besides hard drugs such as cocaine is not the only drug that affects your abilities–drugs such as opioids and over-the-counter medications can also impair you and cause your safety to be at risk.


The police have access to oral fluid drug screeners which are fast, non-invasive, and accurate, and can detect THC. Cause for administering this test to a suspected impaired person can include:

  • red eyes

  • muscle tremors

  • agitation

  • abnormal speech patterns

Other techniques include a Standard Field Sobriety Test, a Drug Recognition Expert Evaluation, and blood tests.

If you have a medical marijuana license, it is advisable to carry it with you at all times.


Employers have a responsibility in the workplace which includes the health and safety of their employees whether it’s physical, psychological, or impairment.

Employees also have a responsibility–work safely, be knowledgeable about their substance intake (medical and non-medical), and the repercussions of taking them, inform bosses if such substances can cause impairment, and obey instructions and policies provided by their boss.

So does this mean bosses can demand a drug test? No!

In Canada, unless undue hardship is a given, we protect most workers against drug testing–whether for recreational cannabis, alcohol, or other drugs, regardless if legal or illegal.

According to the Canadian Human Rights Commission, an employer must consider several factors including the laws, human rights, safety, privacy, labour standards, applicable collective agreements, regulatory requirements, and level of supervision). An employer must also prove undue hardship where health and safety concerns are an issue and the work is safety-sensitive.

Someone holding a magnifying glass

Other probable instances include suspicion of impairment, evidence of reasonable cause, and if the employee is part of a rehabilitation/return-to-work program.

Employers should have training in place for their supervisors and employees on the impact of impairment and what to look for. Employers are also encouraged to use other methods instead of testing such as face-to-face conversations with the employee if there is a suspicion of drug use.

Final Thoughts

In conclusion, if your CBD oil contains a significant amount of THC and you are tested, then yes, you can fail a drug test. If it is your intent to drive or function in an area where impairment is likely, your best recourse is to avoid THC at all costs. Learn how you can buy THC-free CBD oil and what to look for in choosing your products.

Regarding the workplace, an employer must accommodate the use of all the legal and medical authorizations to use and possess cannabis for medical purposes, providing it does not make up an undue hardship. However, the use of medical marijuana does not entitle employees to come to work impaired, or to endanger his/her safety or the safety of others.

The bottom line–know how much THC is in your CBD oil.

Disclaimer: This article does not constitute a legal or medical endorsement. The content on this website should not be a substitute for competent legal advice from a licensed professional attorney in your area.

Do you agree with the driving laws or rules in the workplace as it pertains to THC? Be sure and leave your comments below!

14 thoughts on “Can CBD Oil Cause You to Fail a Drug Test”

  1. This has cleared a boubt I held for weeks now. I didn’t think that one would get in trouble but cbd is always associated with hemp and I was thinking someone could be tested and fail. So a friend of mine is planning on getting a job where she might be tested and she uses cbd. I’ll ask her to check the quantity in her oil just to be sure. Thank you so much for the info.

    • Definitely tell your friend to check out her product and to make sure it is labelled. The last thing she needs is to go to a job interview and be tested for THC, even if it is only a minor trace.

  2. A good article, and very timely.  Though  you are writing about Canada and I am in the U.S., I believe your article shines light on a problem with the CBD industry.

    I am 100% for CBD, as have used it for pain and arthritis for a number of years.  However, I do agree that not all CBD is created equal.  I hate to say it, as too much regulation can be very bad, but I believe there needs to be some sort of standardization established for CBD.  It needs to be properly tested and properly labeled so the customer will know how much CBD and how much THC is in the product.  

    It’s really nice to know that CBD can come from hemp, which is really low in THC.  That makes hemp an even more powerful plant.  It has so many uses — now we can include medical products.

    • Hi Fran. Yes, I do believe the concept does apply to the US as well especially as it is  so large and not all States are on the same page. Thank goodness a lot of the reputable companies are providing third testing and paying attention to their labelling. And a good company will take the time to answer your questions if you can’t find the information on their website. So much as been done and so much more needs to be done.

  3. It happened to an Overseas Filipino Worker friend, he is supposed to be bound for a new work in Japan, but he failed in a medical test here so he wasn’t picked up by the company he applied for just because they found some traces of THC. It is important to buy online from reputable CBD vendors or manufacturers to ensure safety and avoid being suspected as someone who’s using prohibited marijuana.

    • That is absolutely right Gomer! People need to read the labels and find reputable people to work with, not only for safety sake but also to avoid having issues such as your friend did. It would be very disheartening to lose a job opportunity like he did.

  4. I am 420 friendly and get excited reading CBD posts.

    This Question on if CBD oil can cause you to fail a drug test is one i have actively debated on with friends as i was of the believe that it does.

    But reading this has helped me understand better that it doesnt and  have gained more information and insights on the topic for which i am Thanful

    • Glad you like to keep in the loop about CBD. It is a debate that continues and will until people become more educated and understand that THC can be the culprit :).

  5. I got shocked this morning when I was tested for drugs and was tested positive due to the presence of THC in my cbd oil that I used. Thankfully, I was able to present enough evidence to them that “No THC” was inscribed on the product. Then they let me be knowing it wasn’t my fault but wrong inscriptions. I guess there is need to scrutinize more the CBD products in order to prevent sneaky companies from involving THC in them. Mine was made a simpler case because I could present an evidence. Several other cases without evidence attracts serious penalty. Thanks

    • Wow! That is quite a shock and you were lucky. Near the bottom of my article is a link to a CBD Guide. You are right about mislabelling. About 70% cannabidiol extracts sold online are mislabeled.  Dealing with reputable companies is key. Thanks for sharing this story and I am glad it turned out ok for you.


  6. Good afternoon Mary Ann,

    That is a very good question if CBD Oil may cause you to fail a drug test. There is still a lot of mixed-up information out there which easily confuses the first time user of CBD Oil. It is good you wrote this post so people know what the law says and to explain what THC is.

    I have used CBD Oil myself and even gave it to my dog Cindy during the last year of her life. She was a Rottweiler lady, a big birl, and thanks to CBD and some other good things she lived 12 and a half years. That is a lot for big dogs.

    On your About page you said you had some joint pains. I know it is not the same but I still would like to tell you about this. I am 69 now and have been able to improve my bone density by 5% in 2 years. I thought that was quite brilliant, getting older but at the same time getting better bones. I increased my intake on different seeds, especially pumpkin seeds seem to have done the trick.

    I am not a fan of chemical medicine and do not need to take any. In case of need, I would always opt for CBD Oil.

    Regards, Taetske

    • Hi Taetske. So nice to hear from you :). I am glad that CBD was able to help you and Cindy. My daughter has two big dogs and one is nearing his time and in a lot of pain. He also happens to be a Rottweiler. I have tried to convince her to give it a go. 

      I am close in age to you so I am always interested in hearing other stories. I have not considered pumpkin seeds but certainly am not opposed to trying them.  That is quite amazing – 5% in 2 years! Thanks for sharing.

  7. Thanks for this informative article, One of the most interesting aspects of CBD oil is the wide range of medical applications they offer. I am a frequent user of cbd oil for anxiety and ths post has actually enlightened me in understanding  THC in cbd oil,  i haven’t really thought about the implications of too much quantity of THC before taking a drug test, I’ll do well checking out the cbd oil with no or less THC you have provided on this post. Looking forward to more articles from you. 

    • Thanks for stopping by. I don’t think a lot of people are really concerned about THC if they think there is very little in their oil. And in most cases, it is not an issue. However, we know it can be so best to always check the strength of your oil and the THC content.


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