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CBD and Drug Tests – Are you Safe to Use CBD Oil?

12 min read
CBD & Drug Tests

CBD and Drug Tests – Are you Safe to Use CBD Oil?

12 min read

Medically reviewed by

If you ever need to do drug tests, you may be worried about taking CBD in case it flags up and you fail the test. Take a look below at why you shouldn’t need to worry, and the occasional cases you should.

Despite the growing popularity of CBD products, there is still a great deal of misinformation and misunderstanding about the compound. 

Some people still confuse CBD with THC, and some even think that CBD is a drug.

CBD is a non-psychoactive compound with zero addiction or overdose potential. 

Does CBD oil show up on a drug test

It is also legal in the UK and many other countries, as long as the product meets certain specifications.

So you should be able to use CBD oil and not worry about testing positive on a drug test, right?

Well, not exactly.

If you take pure CBD oil that is free from THC, you are very unlikely to return a positive result on a drug test

However, some CBD oil products may lead to a positive result, depending on their composition. There are also a range of other reasons why you may test positive to cannabis or THC after using CBD oil.

If you’ve ever wanted to know:

  • Can I test positive on a drug test after using CBD?
  • What could cause a positive test result even if I haven’t used cannabis?
  • How do I avoid testing positive on a drug test?

You’re in the right place, because we will cover all of this and more below.

We’ve put together a complete guide to drug tests and CBD, how tests work, the reasons you may test positive after using CBD, and how to avoid the problem.

Let’s start with the basics:

What's in this Guide?

Why Would I Need To Take a Drug Test?

First, let’s take a look at why you may need to be concerned about drug tests. For many people, drug tests are not something that they need to deal with.

This may not even be something that has ever crossed your mind.

However, there are a few different situations when you may be called upon to take a drug test, and this could put you in a sticky situation if you are not prepared.

The most common setting where people are tested for drugs is probably at work: routine and random drug testing is becoming increasingly common in the workplace.

In the US, drug testing is routine for:

  • Bus drivers
  • Train conductors
  • Truck drivers
  • Those in the military
  • Some federal government employees

Failing an employer’s drug test could lead to disciplinary action, and could even mean that you lose your job.

Some employers will test prospective employees before they confirm a job offer, so a positive test result could mean you miss out on a job.

There are also situations when you may be subject to a drug test which have nothing to do with employment

For example, pain management doctors may also order a drug test before prescribing medication. 

The police may also test you if you’re suspected of being under the influence of a drug, and it is possible that they may test you for THC if you are in a country where THC is illegal.

Drug tests can use various methods and test for a range of different substances.

They use a sample from your body, most commonly a urine or blood sample, to test for hallmarks of a particular drug or a number of drugs.

These tests generally compare the sample to another sample from someone who has known to have taken the drug, looking for the same reactions.

In essence, the test looks for the body’s reaction to the drug, rather than detecting the relevant compounds or chemicals themselves.

How Do Cannabis Drugs Tests Work?

Like drug tests more generally, there are a range of different methods to test for cannabis use. Although they do so in different ways, the vast majority of tests screen for THC. 

This is the cannabis compound that produces the “high”, and is an entirely different compound to CBD.

Most cannabis drug tests do not look for THC itself. Instead, they test for a compound that the body produces when it metabolises THC. The presence of this compound will indicate that someone has recently taken THC.

Cannabis tests can use different methods, but the most common, particularly in an employment setting, is a urine test. 

The urine is screened to test for the compound mentioned above.

Each test will have a detection threshold: that is, the test will register if there is a concentration greater than the threshold. If the compound is present at a lower concentration, the test will return a negative result.

The detection threshold varies from test to test, but most urine tests will look for results that indicate THC concentration in the body of less than 50ng/mL (nanogram per millilitre). 

This is in line with the maximum dosage recommended for medicinal purposes by the National Institutes of Health and the Substance Abuse and Mental Health Services Administration in the US.

THC is stored in the tissues in the human body, meaning it can be stored for a long time after you have ingested THC. It is stored in fat for weeks, meaning that it is possible to return a positive urine test result for THC even weeks after you’ve smoked a joint or eaten an edible. 

With hair tests, on the other hand, you could have detectable levels of THC in your hair up to 90 after ingestion.

At this point, you’re probably wondering why you need to worry about cannabis testing when CBD is legal to buy, sell and use.

How do cannabis drug tests work
The only reason you'll test positive on a drug test for THC is if you buy from an unreliable seller

Isn’t CBD legal?

Like THC, CBD is a compound that is naturally found in the cannabis plant. However, unlike THC, CBD is non-psychoactive and cannot get you high

It is also non-addictive and does not have the negative side effects that are associated with THC. 

For these reasons, CBD is legal in the UK, the US and many other countries (see our comprehensive list of CBD legality by nation and US state). The CBD product does need to meet certain specifications in order for it to be legal.

 For CBD products to be sold in the UK they must be:

  • No more than 0.2% THC content
  • Produced via an EU-approved strain of industrial hemp

CBD products in the US are required to be:

  • No more than 0.3% THC content
  • Be sourced from hemp grown by a licensed farmer
  • Adhere to both state and federal regulations

A growing number of people are using CBD oil and other CBD products to help promote general health and wellbeing. 

Read more: Benefits of CBD oil

Given its popularity and legality, you may assume that you don’t need to worry about getting into any problems after using CBD because of a drug test result. 

This is true – most of the time. 

But there are certain circumstances where you may be surprised with a test that detects THC, even though you haven’t touched cannabis.

To understand why you may get an adverse drug test result after taking CBD even though CBD is legal, you need to know about the relationship between CBD and THC.

Let’s look at that next:

Is Full spectrum CBD oil legal
Broad spectrum is often better for those who take drug tests because the THC can show up on the results, even though it is a really low amount

Is There THC in CBD?

Although CBD and THC are completely different compounds, many CBD products contain a broad spectrum of cannabinoids, including small amounts of THC

The amount of THC can vary between products, and is subject to legal limits. CBD isolate, on the other hand, is pure CBD and is therefore free of THC.

Some CBD products are marked as “THC free” or “zero THC”, however these can still contain trace amounts of THC. The only way to know that the product is completely THC-free is to verify that it is a genuine CBD isolate. 

However, CBD isolate also lacks the other cannabinoids, making it less useful than full or broad-spectrum CBD oil.

As mentioned, CBD products can only be sold legally in the UK if they contain less than 0.2% THC (out of the total volume), and less than 0.3% in the US. 

These trace amounts of THC are highly unlikely to cause the reaction in your body that will result in a positive drug test.

You would probably need to take more than 2,000 mg of CBD products with 0.3% or less THC to get a detectable result on a drug test. This is far more than most people are likely to consume.

However, depending on your body, it is possible that these trace elements could build up over time to detectable levels. 

Furthermore, mislabellingcross-contamination and a range of other factors may lead to a drug test detecting THC in your system.

Next, we’ll look at these factors in more detail and how you can minimise the risks of getting an adverse test result.

Does CBD oil contain THC
Not all broad spectrum products are the same, but most commonly they have everything but the THC in them

Does CBD Oil Show Up On A Drug Test?

The first reason that you may fail a drug test after taking CBD is because you are using a product that contains THC in higher levels than you suspected. 

You may have purchased a product that is marketed as “THC-free” but still contains trace amounts of the compound.

It is possible that low-quality products contain more than legally allowed limits of THC due to poor production processes. Some low-quality CBD is derived from the marijuana plant. 

If the CBD is extracted from marijuana, rather than from hemp as per UK and US government guidelines, it can contain a much higher concentration of THC.

Mislabeling can also be a problem

Some, less reputable manufacturers and sellers incorrectly label their products, claiming a lower THC level than is accurate. 

Products may also be incorrectly labeled as CBD isolate when they in fact contain a spectrum of cannabinoids, or marketed as being derived from industrial hemp when they are extracted from the marijuana plant

This can mean that you have more THC in your system than you would anticipate.

Remember that even if the CBD product contains THC in trace levels that are normally undetectable, the THC could build up over time in your system and return a positive test result

The amount of CBD that you take will also play a role. 

If you take a moderate amount of CBD, say 25 to 50 milligrams per day, you are much less likely to have detectable THC in your system than people who take higher daily doses.

Can CBD products make you fail a drug test
Different types of tests may also pick up traces of THC - or you may do a CBD-sensitive test

Cross Contamination

Cross-contamination can also cause higher than anticipated levels of THC in CBD products, which may mean that you test positive for THC. 

There may be cross-contamination during the production process, which could result in higher concentrations of THC than advertised. 

This could even result in a CBD isolate that is no longer pure and contains trace amounts of THC. The best way to reduce the risk of cross-contamination is to only buy quality products from a well-known brand.

It is also possible that cross-contamination may occur between finished products. 

For example, at a cannabis dispensary, CBD oil may come into contact with marijuana products and become contaminated with THC. 

However, this is unlikely to happen if you buy your CBD oil from a reputable online retailer.

Different Types of Tests

There are also different types of drug tests, which can influence the result. 

You may return a completely clean result on one kind of test, but display detectable levels of THC on a different test.

As mentioned, THC accumulates in the body and can show up in tests weeks or even months after ingestion. Different tests screen different kinds of samples, which affects how long THC will be detectable. 

Hair tests, for example, screen hair samples which may contain THC for up to 90 days. 

Urine and blood tests, on the other hand, relate to THC that is stored in fat cells, where it is stored for a shorter amount of time.

According to, THC is detectable in regular marijuana users for the following amounts of time:

  • Urine testing: 10 to 15 days
  • Blood testing: up to 25 days
  • Saliva testing: anywhere from 1 to 29 days
  • Hair testing: up to 90 days

Some tests are also more sensitive than others. Most tests will only return a result if there is at least 50 ng/mL of THC, while others can start to show positive results with as little as 15 ng/mL.

Your own body chemistry also affects your test results. 

This can explain why you may return a positive THC test result, while someone else using the same amount of CBD may come back with a negative result

Some people metabolise cannabinoids, including THC and CBD quicker than others, meaning that these compounds stay in their system for a shorter period of time and THC is less likely to accumulate to detectable levels.

Why you may fail a drug test after using CBD
Cross contamination and dodgy products is another issue that can be resolved with more regulation & transparency with lab test results

How Long Does CBD Stay In Your System?

We’ve seen how long THC stays in the body for regular marijuana users, but what about the CBD compound?

Knowing how long CBD stays in your system will allow you to manage the risks associated with drug tests and possible detectable levels of THC

Again, this will depend on a range of things including the dosage and your own metabolism, but you can expect CBD to stay in your body for around a week. 

This means that if you are expecting a drug test at work, it is a good idea to avoid CBD products for seven to ten days beforehand.

The duration of use also plays a role here. If you have just started using CBD, you are highly unlikely to have detectable levels of THC in your system. 

If you’ve been using it for a while, THC levels could have built up in your system over time, depending on your metabolism.

What affects how long cbd stays in your system?
In addition, the method of taking the CBD is likely to make a difference

Other Reasons You May Test Positive To THC

Although unlikely, there are a few other reasons why you may test positive for THC. 

Second-hand exposure to the compound could, in rare cases, result in detectable levels of THC in your system. 

For most people, being around others who are ingesting THC will not have any tangible result, at least, not enough to be visible in a drug test.

However, if you have enough exposure to second-hand THC this could cause high enough levels of THC in your system to be noticeable. 

For example, if you spend several hours in a room with heavy pot smokers, it is possible that this will be enough to show up on a subsequent THC test. 

It is also possible that a marijuana hair test could show a false positive if someone who has had direct contact with the drug has touched your hair.

CBD breakdown in the body could also be blame for a false positive result on a THC test. Some experts believe that CBD could break down into THC in the system. 

These would be very small amounts of THC that would not be enough to give you a high, but could show up in a drug test. 

However, the science is not conclusive: one study found that CBD oil could break down into THC in the stomach, while other studies found no evidence of this

It is, however, theoretically possible.

Finally, you should be aware that CBD sensitive tests are available, although they are rare. 

These tests can reliably detect CBD in the system. 

It is, however, unlikely that you will be subjected to a CBD test as the compound is a legal and non-psychoactive substance in many countries around the world.

why you might test positive for THC
Even if you test positive, it will likely be extremely low amounts in these cases

How Do You Avoid Testing Positive On a Drug Test?

As we’ve seen above, it is impossible to say that you will not test positive for THC after using CBD products. 

It is most likely that your test will be negative, but a range of factors come into play and there are many reasons why you may have detectable levels of THC in your system, even if you haven’t ingested marijuana. 

Any CBD brand that guarantees their product will never result in a positive test result for THC is, frankly, lying.

However, there are some steps you can take to avoid a positive THC result, or at least to manage the situation.

Using high-quality CBD products means that you can be more certain of the concentration of CBD. 

Whether you are using a product that is THC-free or contains only minimal levels of THC, ask for a manufacturer who can show you a Certificate of Analysis, or COA. 

This will avoid products that are mislabelled, leading you to take higher concentrations of THC than you were aware of.

You should also check that the product is derived from government-approved hemp crops. These plants have lower concentrations of THC, so make sure the product you buy complies with these rules. 

For example, our products are derived from 100% organic hemp and we work closely with the farmers to simplify the supply chain and deliver all-natural CBD.

If you’re expecting a drug test, knowing the type of test will also help you to be prepared. If your employer uses urine testing, urine testing, for example, you know that it will only pick up use from the last week or so.

Given that the risk is always there, communication is your best bet to manage the situation. 

In most situations, it will be a good idea to speak to your boss, potential boss, or whoever is ordering the test ahead of time, and explain to them that you use CBD products for the benefits.

That way, if you do return a positive result they will know why. 

They are much more likely to be understanding if you explain ahead of time rather than afterwards!

How to avoid testing positive on a drug test
Thoroughly researching a seller is crucial before buying CBD to avoid a sticky situation like this


The bottom line? 

Even though CBD is legal, you might still test positive for THC on a drug test after using CBD products

This is unlikely: in most cases, the concentration of THC in your system will not be high enough to be detectable in a drug case. 

However, there are a number of factors that mean you could return a positive test result.

You can protect yourself by choosing the right product, as well as keeping an eye on the amount of CBD you use and for how long before an upcoming drug test.

Above all, open communication will help you to avoid misunderstandings if you do return a test result that is positive for THC.

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