The content provided on this blog is intended for educational purposes only and should not be construed as medical advice. We strongly advise readers to seek guidance from a qualified healthcare professional regarding any medical concerns.

To reflect its medicinal nature rather than recreational use, we prefer the term ‘medical cannabis’ over terms such as ‘marijuana’, “grass”. or ‘dope’ which may carry negative connotations.

The opinions expressed in the blog belong to the respective authors, who are not medical professionals, and may not necessarily align with those of Lyphe Clinic. Lyphe Clinic does not endorse any specific products or services mentioned, except those provided through Lyphe Clinic.

Readers should be aware that the legality of medical cannabis varies by location, and this disclaimer may be subject to periodic updates.

Lab technician with a plasma blood sample.

Key Points

  • Detection times for medical cannabis use vary depending on the method of consumption, frequency of usage, and individual factors (e.g., metabolism, body-fat percentage, diet, hydration, and physical activity).
  • Urine testing is the most common method of identifying cannabis use. Detection times for urine range from a few days (three to seven days) for light use and several weeks (more than 30 days) for heavy usage.
  • Blood and saliva testing are reliable methods of identifying recent cannabis use, with detection times ranging from a few hours to several days.
  • Traces of cannabis by-products can remain in hair strands for as long as 90 days, contingent upon the frequency of usage. However, this form of examination is rarely utilised due to its high cost and the need for a specialised lab.
  • Medical cannabis patients and recreational users need to consult with a healthcare professional to determine the optimal dosage and frequency of use to minimise the time it remains detectable in the body.


With the increasing popularity of medical cannabis, it is essential to understand how long cannabis stays in your system. Cannabis detection – including medical cannabis use – may affect employment, travel, child custody, and other important aspects of your life. To this end, this blog post aims to provide a detailed overview of cannabis detection times in blood, urine, saliva, and hair, shedding light on this important topic for patients seeking medical cannabis treatments. 

However, this post is intended for informational purposes only and should not be construed as medical advice or a substitute for professional medical treatment.

Lyphe: The Leading Medical Cannabis Clinic in the UK

The logo of Lyphe Clinic.

If you’re seeking a definitive authority on medical cannabis in the UK, look no further than Lyphe Clinic. We are the UK’s foremost clinic for medical cannabis advice and treatment. No one understands the intricacies of cannabis and its physiological impact quite like we do.

Our experienced medical professionals don’t just offer advice; they design tailored treatment plans that can revolutionise your healthcare journey. Whether you’re grappling with chronic pain, epilepsy, multiple sclerosis, or other conditions that qualify for medical cannabis therapy, we’ve got the expertise to steer you toward a life enhanced by evidence-based treatments.

Don’t just take our word for it – experience the Lyphe difference yourself. Book an appointment today with a true expert in the field. Your well-being is too important to leave to chance, and at Lyphe, you’re in the safest of hands.

Cannabis and Its Metabolites in the Body

When exploring how long cannabis stays in your system, it’s essential to delve into the role of cannabis metabolites, which are the by-products formed when your body processes and breaks down substances like THC (tetrahydrocannabinol), the primary psychoactive compound in cannabis. These metabolites are key players in determining the duration of cannabis detection in various drug screenings.

THC Metabolism in the Body

When you consume cannabis through smoking, vaping, edibles, or cannabis liquid, THC enters your bloodstream and begins to interact with your endocannabinoid system. As your body processes THC, it undergoes chemical transformations, resulting in the formation of various metabolites. The primary metabolite of interest in drug testing is THC-COOH (11-nor-9-carboxy-Δ⁹-tetrahydrocannabinol).

The Role of THC-COOH

THC-COOH is a non-psychoactive metabolite of THC, and it is lipid-soluble, which means it can accumulate in fatty tissues throughout your body. This characteristic is the reason THC-COOH is commonly utilised as an indicator of previous cannabis consumption in drug screenings, especially in urine tests.

Cannabis Detection in Urine Tests

A urine specimen subjected to a colour-based litmus test.

Urine test for cannabis is the most prevalent method employed, owing to their convenience and cost-effectiveness. As mentioned above, THC metabolites, primarily THC-COOH, are identified in urine. Importantly, detection times in urine can vary widely based on usage patterns:

  1. Occasional Use (one-time usage): According to a 2017 review published in Mayo Clinic Proceedings, the average detection time for occasional cannabis users is between three to four days.
  2. Regular Use (up to four times weekly): For regular users, detection times of THC in urine can extend to one to two weeks.
  3. Chronic Use (daily consumption): Chronic users may test positive for THC-COOH for several weeks to a month.

These estimates provide a general guideline, as personal variables such as metabolic rate and hydration status can impact the outcome of cannabis identification tests. We at Lyphe recommend that patients consult with a medical professional to determine the optimal dosage and frequency of cannabis use in order to minimise detection times.

Cannabis Detection in Blood 

Blood test for cannabis is another method of detecting usage. THC and its by-products travel through the bloodstream after consumption, making it detectable through a blood test. The timeframe within which cannabis can be identified in the blood is more limited than in urine, varying from a couple of hours to a handful of days.

A research paper published in the journal Pharmacology, Biochemistry, and Behavior found that the detection time for cannabis in blood tests highly depends on the consumption method. Inhalation, such as smoking or vaping, has a shorter detection window of up to six hours, while ingestion may extend this to 12 hours or more.

In addition to this, individual factors such as body fat, metabolism, and frequency of use can also influence results. Therefore, our experts at Lyphe advise patients to wait at least 24 hours after medical cannabis usage before taking a blood test, in order to optimise the chances of a clean result.

Cannabis Detection in Saliva

Close-up of medical professional preparing a test tube and swab for a saliva examination.

Saliva testing for cannabis is a relatively new method of checking recent use. It’s becoming increasingly popular for on-the-spot screening. More specifically, THC is present in saliva after consumption and can be detected through an oral fluid test. The span within which cannabis can be found in saliva closely aligns with that in blood, ranging from a few hours to multiple days.

A 2022 study published in Physiological Research suggests that THC can be detected in saliva for up to one to two days in occasional users and up to four to six days in regular users. Saliva tests are highly reliable in detecting recent cannabis use, as noted by a study published in Clinical Chemistry.

Essentially, this rapid detection window makes saliva examinations ideal for identifying recent impairment, ensuring patient safety, and adhering to UK laws regarding driving under the influence of drugs. 

Cannabis Detection Through Hair

Close-up of a hair sample for lab testing.

Hair examinations provide a more extended view of cannabis consumption, rendering them less appropriate for identifying recent use. These assessments capture traces of THC by-products within hair strands, usually with a timeframe extending up to 90 days.

Similarly, as per a 2019 research paper in BMC Chemistry, this approach is useful for scrutinising prolonged cannabis usage. To this end, it might not be the most fitting option for real-time oversight of patients undergoing medical cannabis therapy, owing to limitations in both timing and sensitivity.

It is important to note that scientific research on cannabis detection through hair is ongoing, and factors like hair colour, type, and growth rate can affect the results. Therefore, it’s important to consider these factors when interpreting results for medical cannabis patients.

CBD, Minor Cannabinoids, and Cannabis Drug Testing

In the evolving landscape of cannabis consumption, many individuals are turning to CBD-rich strains and products for their potential therapeutic benefits. CBD, which stands for cannabidiol, is non-psychoactive, unlike THC. This makes it an attractive option for those who wish to experience relief without the “high” associated with cannabis use. However, when it comes to drug tests, it’s essential to understand how CBD and other cannabinoids fit into the picture.

CBD and Drug Tests

Standard drug examinations, such as urine and blood tests, are typically designed to find THC and its metabolites, not CBD. This means that the presence of CBD alone is unlikely to trigger a positive result in a drug test.

However, full-spectrum CBD products include a range of cannabinoids, including trace amounts of THC. While unlikely to induce intoxication, they may still be detectable in drug tests. There’s also increasing popularity of “high-CBD” strains as a replacement for THC and tobacco. Thus, even with a greater concentration of CBD in these alternatives, they may still trigger a positive result in drug screenings.

For instance, a 2021 study published in Forensic Science International suggests that repeated consumption of high-CBD cannabis can lead to the identification of THC-COOH in urine tests for up to 15 days from usage, while THC can be identified in oral intake tests for up to three hours.

Minor Cannabinoids and Drug Tests

In addition to CBD and THC, the cannabis plant contains hundreds of minor cannabinoids, each with potential therapeutic properties. Examples include CBG (cannabigerol), CBN (cannabinol), and THCV (tetrahydrocannabivarin). Research on these minor cannabinoids is still in its early stages, but they may play a role in the entourage effect, where multiple cannabinoids work together synergistically.

When it comes to drug screenings, the detection of minor cannabinoids largely depends on the specific test’s sensitivity and focus. Standard drug tests typically do not target minor cannabinoids because they are not associated with intoxication and are often present in much smaller quantities than THC.

Summary Table 

Testing Method Detection Times Factors Affecting Detection Applicability Notes
Urine  3-4 days for occasional users 

1-2 weeks for regular users 

Up to a month for chronic users



Frequency of Use

Most common method Primarily identifies THC-COOH
Blood  Hours to several days Consumption method

Body fat 


Identifies recent use Inhalation has a shorter detection window
Saliva Hours to multiple days Frequency of use

Recent consumption

On-the-spot testing; recent use detection Highly reliable for recent use
Hair  Up to 90 days Hair type

Hair color 

Growth rate

Long-term detection Expensive and rarely used
CBD and Drug Tests Unlikely to be detected unless full-spectrum products are used Types of cannabinoids present Not standard in tests Full-spectrum products may contain THC
Minor Cannabinoids Depends on the test’s sensitivity Not yet fully researched Not standard in tests Not typically the target of standard tests


Understanding how long cannabis remains detectable is crucial for both medical patients and recreational users. This window can vary based on factors like frequency of use, dosage, and method of consumption.

Urine tests are the prevalent means for detecting cannabis consumption, and they can reveal usage spanning a period from several days to multiple weeks. Blood and saliva assessments are also dependable for identifying recent cannabis intake, with identification timeframes varying from just a few hours to a handful of days.

As a reputable medical cannabis clinic in the UK, we at Lyphe advise patients to consult with our healthcare experts for personalised guidance on optimal dosage and frequency to minimise the time cannabis remains detectable. We are dedicated to offering precise information and expert advice on medical cannabis use – schedule an appointment with one of our specialists today!  

Frequently Asked Questions (FAQs)

How long does cannabis liquid stay in your system?

The duration cannabis liquid stays in your system can vary based on factors such as usage frequency and metabolism. Generally, it can be detectable in urine for up to several days to a couple of weeks for regular users, while blood and saliva examinations can reveal recent consumption within a timeframe stretching from hours to several days.

How long does Delta-8 stay in your system?

Delta-8 THC, like Delta-9 THC, can vary in how long it stays in your system depending on factors like usage frequency and metabolism. On average, it can be detectable in urine for up to two to three days for occasional users and up to several weeks for frequent or chronic users.

How do you flush Delta-9 from your system?

To flush Delta-9 THC from your system, staying hydrated and engaging in regular physical activity may assist in hastening the process. However, it’s essential to note that there is no foolproof method to quickly eliminate it, and the most effective strategy is simply the passage of time coupled with reduced intake.

What is the average detection time for occasional cannabis users?

For occasional cannabis users, the average detection time in urine tests is typically around three to four days after use, but it can vary depending on factors like dosage and metabolism. Moreover, blood and saliva tests may indicate recent use within hours to a few days for occasional users.

What is the detection window for cannabis in saliva tests?

Saliva tests for cannabis can generally detect its presence within hours to a few days after use. However, the exact detection window can vary depending on factors such as usage frequency and the sensitivity of the test.


Gerace, E., Bakanova, S. P., Di Corcia, D., Salomone, A., & Vincenti, M. (2020). Determination of cannabinoids in urine, oral fluid and hair samples after repeated intake of CBD-rich cannabis by smoking. Forensic Science International, 318, 110561. https://doi.org/10.1016/j.forsciint.2020.110561

Grotenhermen, F., Leson, G., Berghaus, G., Drummer, O. H., Krüger, H. P., Longo, M., Moskowitz, H., Perrine, B., Ramaekers, J. G., Smiley, A., & Tunbridge, R. (2007). Developing limits for driving under cannabis. Addiction (Abingdon, England), 102(12), 1910–1917. https://doi.org/10.1111/j.1360-0443.2007.02009.x

Shah, I., Al-Dabbagh, B., Salem, A.E. et al. A review of bioanalytical techniques for evaluation of cannabis (Marijuana, weed, Hashish) in human hair. BMC Chemistry 13, 106 (2019). https://doi.org/10.1186/s13065-019-0627-2

TROJAN, V., LANDA, L., HRIB, R., JURICA, J., RYCHLICKOVA, J., ZVONICEK, V., HALAMKOVA, L., HALAMEK, J., DEMLOVA, R., BELASKOVA, S., & SLIVA, J. (2022). Assessment of Delta-9-Tetrahydrocannabinol (THC) in Saliva and Blood After Oral Administration of Medical Cannabis With Respect to its Effect on Driving Abilities. Physiological Research, 71(5), 703-712. https://doi.org/10.33549/physiolres.934907  

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