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Does CBD Oil Show in a Blood Test?

As the global popularity of Cannabidiol (CBD) continues to surge, many consumers have pressing questions about its implications on various aspects of their lives, one of which revolves around medical examinations. 

Specifically, many are keen to understand if and how CBD oil might be detected in blood tests. This topic not only has implications for those undergoing medical examinations but also for employees who might be subjected to workplace drug screenings. 

Throughout this article, we will delve into the specifics of CBD oil, the types of blood tests available, and whether typical tests can identify CBD.

Does CBD oil show in a blood test - The short answer:

No, standard blood tests in the UK typically target THC, the psychoactive component of cannabis, and not CBD. While there are specific, rare tests that can detect CBD, they aren't commonly used in medical or employment screenings. However, it's crucial for consumers to ensure their CBD oil is genuinely THC-free, as many CBD companies still offer products that may contain trace amounts of THC due to insufficient regulation. If consumed, these trace amounts could potentially be detected in a blood test, especially if the test is sensitive and the usage is frequent.

Understanding CBD Oil and Its Components

When considering the intricacies of CBD oil, it's essential to grasp its individual constituents. Each component, from CBD itself to the range of other compounds it may contain, can deeply influence its potential effects and benefits.

What is Cannabidiol (CBD)?

Cannabidiol, more widely known as CBD, is one of the primary cannabinoids found in the hemp plant. Distinct from THC, CBD does not produce any intoxicating effects and is the key ingredient in CBD oil. It's believed to provide various health benefits, which has driven its appeal as a versatile food supplement.

Differences Between CBD and THC

CBD and THC, though both cannabinoids, diverge greatly in their properties. CBD is non-intoxicating, while THC generates the well-known euphoric 'high' that many associate with cannabis. In the UK, CBD products are legal, but they must be free from THC and other controlled cannabinoids. This distinction is crucial in the effects they evoke and in a legal and regulatory sense.

Common Types of CBD Oil

Various formulations of CBD oil exist, made from various different CBD extracts, each with its own unique profile:

Whole-Plant: Utilises the entire hemp plant, capturing all cannabinoids, terpenes, and natural constituents. Due to the presence of THC and other controlled cannabinoids, whole-plant products are illegal in the UK.

Full-Spectrum: Contains all the plant's natural compounds, including CBD. Like whole-plant products, full-spectrum CBD oil may also have traces of THC and other controlled cannabinoids, rendering them illegal in the UK.

Broad-Spectrum: This THC-free variant includes a wide array of cannabinoids and terpenes, excluding THC. Being free from controlled cannabinoids yet retaining other beneficial compounds makes broad-spectrum CBD products the best legal option in the UK, providing a balance between purity and the "entourage effect", where multiple cannabis compounds work together, potentially amplifying their beneficial effects.

Narrow-Spectrum: Features a limited selection of cannabinoids and terpenes.

CBD Isolate (pure CBD): This is the purest form, consisting only of CBD, with every other compound removed.

Each type presents distinct advantages and disadvantages, catering to different user preferences and needs.

The Composition of CBD Oil

CBD oil typically blends a carrier oil, like coconut or hemp seed oil, with the chosen CBD extract. Some products also incorporate added nutrients or flavours to enhance taste or to augment potential health benefits. The quality of the chosen components, combined with the extraction method used, impact the product's efficacy and safety.


Health Benefits, Risks, and Medical Opinions of CBD Oil

CBD oil has gained immense attention not only for its therapeutic possibilities but also for the ensuing debate among healthcare professionals about its safety and efficacy.

Potential Health Benefits of CBD Oil

CBD has been lauded for its potential therapeutic properties, with some users and studies suggesting it may help alleviate symptoms related to:

  • Pain and inflammation
  • Anxiety and depression
  • Sleep disorders
  • Neurological disorders, including epilepsy
  • Skin conditions like acne

It's crucial, however, to note that while these potential benefits are promising, not all have been robustly substantiated by comprehensive scientific studies.

Concerns and Risks Associated with CBD Use

While CBD oil's potential therapeutic benefits have garnered significant attention, it's essential to be aware of the risks associated with its use. These risks can range from relatively mild symptoms to more severe complications, primarily when consumed in large doses.

  • Potential for liver damage with high doses: This is a more severe concern and is generally linked to consuming large quantities of CBD.
  • Interaction with other medications: This could affect the effectiveness or safety of other drugs being taken.
  • Risk of contamination if not sourced from reputable producers: Without strict quality control, CBD products might be tainted with pesticides, heavy metals, or other contaminants.
  • Gastrointestinal problems, including diarrhoea: Typically a milder symptom, it might be experienced by some users.
  • Changes in appetite and weight: These are also relatively mild side effects, though they can be of concern for certain individuals.

Moreover, when purchasing CBD oil in the UK, ensuring it's free from controlled cannabinoids is not only about quality but also legality, as their presence is illegal.

Medical Opinions on CBD Oil Use

The medical community's stance on CBD oil remains mixed. While some healthcare professionals acknowledge its potential therapeutic benefits, others stress the importance of caution due to limited conclusive research. Many physicians in the UK might recommend CBD oil as a complementary therapy but are unlikely to suggest it as a primary treatment option until more comprehensive data emerges.

The Need for Further Research on CBD Oil

There's a pressing need for more rigorous and wide-reaching studies to better understand CBD oil's safety profile, efficacy, and long-term effects. While anecdotal evidence and preliminary studies provide insights, further clinical trials are crucial to confirm CBD's therapeutic potential and establish clearer dosage guidelines.


Drug Screening Tests in the UK

As drug screenings become more prevalent in various sectors across the UK, it's essential to understand the types, purposes, and typical substances detected.

Types of Drug Screening Tests

There are several ways that drug tests screen for the presence of drugs:

Blood Tests: Direct and accurate, they can identify both the drug and its metabolites, indicating recent use.

Urine Tests: The most common screening method, urine drug tests can detect drugs days after consumption, but they primarily indicate past use rather than current impairment.

Saliva Tests: Useful for detecting recent drug use, especially in scenarios like roadside drug testing.

Hair Tests: Can provide a longer history of drug use, often up to 90 days or more, but they can't identify recent consumption.

Typical Applications of Drug Tests in the UK

Blood tests, offering a direct and accurate means of detecting drugs, are utilised in various sectors across the UK. This type of test can identify both the drug and its metabolites, which can be critical in certain situations:

Roadside Testing: If law enforcement suspects drug-impaired driving, a drug test might be used to confirm the presence of controlled substances. This generally won't be a blood test, but in some cases, a blood test may be requested later, especially when accuracy is imperative.

Accidents & Injuries in the Workplace: In safety-sensitive jobs, post-accident blood tests can determine if drug use played a role.

Legal or Forensic Reasons: Courts may order blood tests in scenarios like serious drug-related crimes or vehicular accidents where substance impairment is suspected.

Sports: In cases where there's suspicion of performance-enhancing drugs, blood tests may be used for their accuracy.

Substances Commonly Detected by Blood Drug Tests

While various substances can be detected through blood tests, certain drugs are more commonly sought after due to their prevalence and the potential for impairment:

THC: The psychoactive component of cannabis. Blood tests are especially valuable for detecting recent cannabis use.

Cocaine: Including its primary metabolite, benzoylecgonine, which can be detected for a few days post-consumption.

Opiates: Such as heroin and morphine, may be present in the blood for up to 36 hours after use.

Amphetamines & MDMA: Drugs like methamphetamine and ecstasy remain detectable in the blood for a short window, often up to 48 hours.

Benzodiazepines: Some of these, like diazepam and lorazepam, may be detectable for several days, especially with prolonged use.

Remember, the detection window can vary based on the individual's metabolism, the dose, and the frequency of use.


Medical Blood Tests in the UK and CBD's Potential Impact

Medical blood tests are an essential tool for healthcare professionals in the UK to diagnose and monitor various conditions, illnesses, and health indicators. Given the increasing popularity of CBD oil, questions have arisen about its presence or impact on these tests.

Common Medical Blood Tests in the UK

Full Blood Count (FBC): Evaluates overall health and detects various disorders like anaemia or infection.

Biochemistry (or Chemical) Profile: Measures different chemicals in the blood, informing about heart, kidney, and liver functions and electrolyte balance.

Lipid Profile: Measures cholesterol and triglycerides, which can indicate heart disease risk.

Liver Function Tests (LFTs): Assess how well the liver works and looks for any signs of liver damage.

Glucose Test: Determines blood sugar level, typically used for diagnosing or monitoring diabetes.

CBD's Influence on Medical Blood Tests

Detectability: Standard medical blood tests do not look for CBD; hence it's unlikely to be identified. However, as with any substance, specific tests can be designed to detect CBD, though these are not common in the medical field.

Impact on Results: Some research suggests that in very high doses, CBD might affect liver enzyme levels, which could potentially influence the results of liver function tests. But, it's vital to understand that typical CBD usage is unlikely to result in such significant changes. Still, if someone is consuming large amounts of CBD, they should inform their doctor prior to undergoing medical blood tests.

Interactions with Other Medications: While CBD doesn't typically interfere with blood tests, it may interact with certain medications that affect blood test results. Always disclose any CBD or other supplements you're taking to your healthcare provider.


The Detectability of CBD and THC in Blood Tests

While both CBD and THC originate from the cannabis plant, their detectability and interactions with blood tests differ significantly. 

CBD and Blood Test Interactions

Detectability: While standard medical blood tests in the UK don't actively screen for CBD, there are specific tests, albeit rare, which are designed to detect its presence. These are usually applied in unique research or clinical contexts. For the average user, the detection window for CBD in blood remains brief, typically lasting only a few hours after consumption.

Factors Influencing Detection: Several variables can alter the detectability of CBD. The dose, frequency of use, metabolism, and other individual characteristics can all play a role in how long CBD remains traceable in your system.

THC's Presence in Blood Tests

Detection Window: In contrast to CBD, THC has a more extended presence in the bloodstream. It can be detectable in blood tests for up to 3-7 days after consumption. However, for individuals who consume cannabis more regularly or those with a higher body fat percentage, THC might remain traceable for an even longer period.

Specific Tests for THC: Most standard drug tests, especially in contexts like employment screenings or roadside checks, focus on THC detection. A positive drug test result is not just triggered by the active THC compound but also its various metabolites, indicating recent usage.

Avoiding THC in CBD Oil

In the UK, the legal standard is that CBD oil should be free from all controlled cannabinoids, including THC. However, due to insufficient regulatory systems, many CBD products still containing THC remain available in the market. For consumers, this poses the challenge of ensuring the purity of the CBD products they purchase.

Understanding CBD Product Labels

When choosing CBD oil, a keen eye for product labels can help ascertain the potential presence of THC (or how much THC). Labels that indicate products as "whole-plant" or "full-spectrum" typically contain THC. Additionally, be cautious of labels that use vague or ambiguous terminology such as "low THC" or "traces of THC". Ideally, products should clearly state "no THC" or "THC-free" to ensure compliance with UK legal standards.

Importance of Third-Party Lab Reports for CBD Products

Even if a product is labelled as "broad-spectrum", "isolate", or "THC-free", there's no guarantee it's devoid of controlled cannabinoids. This is where third-party lab reports come into play. Always rely on these reports to verify the absence of THC and other controlled cannabinoids, as they provide an unbiased assessment of the product's cannabinoid profile.

Reading CBD Lab Results

Lab reports can seem complex, but a few key areas need attention. Look for sections that detail cannabinoid profiles, ensuring no detectable levels of THC or other controlled cannabinoids are present. Familiarising yourself with the specific terminology and reading formats of these reports can help users make informed choices about their CBD products.


Public and Employment Implications of CBD Oil Usage

Navigating the implications of CBD oil usage in the workplace can be complex, primarily due to misconceptions about the product and its association with THC.

Employer Concerns about CBD Oil

CBD, on its own, is non-psychoactive and doesn't impair cognitive abilities. However, some employers may still harbour concerns, largely due to misconceptions about the product or confusion with THC-containing cannabis products. The key issue lies in the potential presence of THC in mislabelled or non-compliant CBD products, which might lead to positive drug tests or altered job performance.

In the UK, CBD oil that is free from controlled cannabinoids like THC is entirely legal. Consumers have every right to use such products without facing legal repercussions. However, it's crucial for users to ensure that their CBD oil is genuinely THC-free to avoid any inadvertent legal issues. This includes the potential penalties associated with driving after consuming mislabelled CBD products that contain THC.

Discussing CBD Oil with Your Employer

There's no reason to be apprehensive about discussing CBD oil usage with employers, especially if one is confident in the product's legality and compliance. Transparent communication can clear up misconceptions and establish trust. If an employer does express concerns or demonstrates discrimination against legal CBD use, employees can:

  • Provide educational resources about CBD to dispel myths.
  • Share third-party lab results to confirm the product's THC-free status.
  • Seek legal counsel if discrimination persists, as employees have rights and should not be penalised for using legal wellness products.

By being informed and proactive, CBD users can foster understanding and maintain a positive workplace environment. Attending events like the annual 'CBD Show' in London can also help professionals stay updated on the latest in CBD research, products, and regulations."



As drug screenings, particularly blood tests, become more commonplace in the UK, understanding how these tests detect substances like THC and CBD becomes essential. While CBD itself is typically not detected in standard medical blood tests, THC, another compound found in cannabis plants, can be detected for days post-consumption. 

In the context of the UK's legal framework, CBD oils should be completely free of THC, making third-party lab reports a crucial tool for consumers. In the workplace, while CBD itself doesn't impair cognitive abilities, misconceptions persist, necessitating open communication between employees and employers. It's essential for consumers to remain informed and proactive, ensuring the products they consume are compliant with the law, and fostering understanding in their professional and personal spheres.