How Long Does Cannabis Stay in Your System For?

Ingesting cannabis – whether that is by inhaling or eating it – can cause an intense high, but this often fades very quickly from your system. Within a few hours, you will likely feel sober again as you metabolise weed over time.

Although feeling high from smoking or ingesting weed does not last long, how long cannabis stays in your system is significantly longer. It typically takes a significant amount of time before weed is undetectable in your system.

Find out more about how cannabis is detected in your system, testing methods for weed, and find out how long cannabis stays in your system for below.

Testing Methods to Detect Cannabis in Your System

Have you ever wondered how long does weed stay in your system for after you have smoked or ingested it? There are a variety of testing options that may be used to detect cannabis in your system, including blood tests, saliva tests, urine tests and hair follicle testing.

The shortest amount of time weed can be detected in your system is via blood tests, and the longest is through hair follicles. Find out more about the cannabis testing methods below:

Blood Testing

Blood testing is not often used to detect cannabis, as weed is fairly quickly eliminated from your blood within 24-48 hours of consumption. However, this can depend on the amount and frequency of your cannabis usage.

If you are an occasional user of cannabis, weed stays in your system for roughly 24 hours, although timescales vary. People who tend to smoke more regularly will likely have a detectable amount of cannabis in their blood for a longer time, varying from 48 hours to a week. The type of cannabis you ingest will also factor towards the half-life of the drug and how long weed stays in your system for.

THC – the active substance in cannabis – is the material that is tested for in blood tests. The half-life of cannabis is dependent on the concentration of THC within the cannabis you have ingested, whether that is through a joint, a weed pen, or an edible.

A weaker strain of cannabis will leave your bloodstream as quickly as a weaker cannabis strain, so this also factors into how long cannabis stays in your system for.

Saliva Testing

Saliva testing is another way to test for cannabis in your system. Weed can be detected in your salvia for roughly 24-72 hours after consumption, but this depends on the strength of THC, the amount ingested, and your body’s metabolism.

A saliva test is commonly conducted by police on drivers who are potentially under the influence with weed in their system.

Urine Testing

The most common way of testing for the presence of THC in the human body is through urine testing. As cannabis does not break down easily through urine, this is a common method to detect weed in the system. A one-off smoker will find that weed stays in the system for up to 30 days, and a regular user could test positive for THC as long as three months after last using the drug.

The only way to avoid a positive THC test is to avoid smoking cannabis altogether. If you are struggling to cut down your weed consumption, you may be suffering from a Cannabis Addiction. We offer Cannabis Detox and Cannabis Rehab at Ocean Recovery.

Hair Follicle Testing

Hair follicle testing is used by various testers to detect heavy cannabis use and is commonly used as a test for court cases or other legal proceedings. If you are a recreational user who rarely ingests cannabis, hair follicle testing would not be effective, and urine, blood or saliva tests would likely be used. This is because cannabis particles would only show up in your hair after repeated cannabis use for a prolonged period.

Factors That Influence How Long Weed Stays in Your System

How long cannabis stays in your system is not the same for every person. This can depend on a number of factors, from sex, your metabolism, your tolerance to weed, and more. See some key factors that influence how long cannabis stays in your system for below:


Every person has a different metabolism which affects how long weed stays in their system for. The faster a person’s metabolism, the faster weed will be flushed out of the system naturally.

THC Levels

Different types of weed contain higher and lower levels of THC, which is the psychoactive compound in cannabis that causes you to feel high. Weed pens typically contain higher levels of THC and CBD, and joints are commonly less potent, especially if mixed with tobacco.


Genetics also factor into how long cannabis stays in your system, from feeling the sensation of being high, to how long weed remains in your system for.

Does the Type of Weed Affect How Long It Stays in Your System for?

Many people wonder if edible weed stays in your system longer than a joint, but the way that you consume cannabis does not have an effect on how long it remains in your system. It instead depends on the levels of THC in the marijuana consumed, as weed edibles, joints, weed pens, bongs or smoking devices all have different strengths of weed.

If you have consumed cannabis, it is important that you do not drive or do any activities that require you to be sober. Even if you no longer feel high, cannabis is still likely in your system and you can be prosecuted for driving under the influence if tested for cannabis in your system.

If you are concerned about your weed use or are worried about a loved one, get in touch with us today for advice. Cannabis abuse and addiction happen to many people in the UK – you are not alone.

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John Gillen - Author - Last updated: October 6, 2023

John is one UK’s leading professionals in the addiction recovery industry. Pioneering new treatment techniques such as NAD+ and ongoing research into new therapy techniques such as systematic laser therapy, John is committed to providing the very best treatment for people throughout the UK and Europe. During his extremely busy schedule, John likes to regularly update our blog section with the latest news and trends in the industry to keep visitors to our site as well informed as possible on everything related to addiction treatment.