How long does THC stay in your system?
How long does weed stay in your system? THC is detectable in bodily fluids, such as urine, for 30 days or more. It can remain for up to 90 days in the heaviest users. The heavier and more frequent users will retain traces of weed and THC for longer. Lighter cannabis users will retain traces of THC for shorter periods.
Generally speaking, detection time is easiest in human hair. A hair test can indicate cannabis use even if the hair test happened several months after the cannabis was consumed. In addition to hair testing, THC is also detectable in urine, sweat, oral fluid, and blood tests.
How does the detection of THC in your system work?
The misguided war on cannabis has empowered many managers to test their staff for weed use. Many types of THC testing are at their disposal. Below are a few, alongside some technical information about their effectiveness.
Blood testing for cannabis use/THC
How long does THC stay in your blood system? Between 2 and 7 days according to this study of 25 heavy cannabis users. Only blood tests from the heaviest long term cannabis users showed the presence of THC after 7 days.
Urine testing for THC and weed use
How long does THC stay in your system with a urine test? A single use of cannabis could be detected in a urine test 2-7 days after the event. But studies indicate that heavy cannabis users could give positive urine tests up to 2 months later. The limit is thought to be around 3 months. THC is stored as a metabolite (known as ‘THC-COOH’) by the body in fat cells after use. It is slowly released by the fat cells in a way that urine tests can easily show. That’s the reason why skinnier people with lower fat deposits are more likely to pass THC urine tests earlier than they would if they had significant fatty tissue deposits.
Saliva tests for THC/cannabis use
How long does THC stay in saliva? According to studies, about 2-3 days for an occasional user, up to a month for regular heavy users.
As with blood and urine tests, the following basic rules apply. How recently you last used cannabis will affect the result, the more recent the use the greater the chance of a positive result. Likewise consumption plays an important role, the more you vaped/smoked, the greater the chances that the test will detect it.
Note that the saliva test doesn't look for THC metabolites (products formed from the break-down of THC). Instead the saliva test just looks for the presence of pure THC in your saliva. Good oral hygiene, and the use of dilution tactics (where possible) are the best approach for beating a saliva test.
Hair testing for THC and cannabis use
How long does THC stay in hair? According to scientific studies,90+ days. The hair follicles are supplied with blood. This carries the tell-tale signals of cannabis. The cannabis metabolic residues are locked into the hair tissue where they remain detectable several months after consumption. Human hair grows at just over 1cm per month, so anyone with just 3-4cm of hair would be testable for cannabis use over the previous 3 months.
How long does THC stay in your system chart
How long does THC really stay in your system? The answer depends on a few factors, including the test method. The amount of cannabis you use and the frequency of use can all play a part. As can the individual amount of body fat. The chart, below, shows what you can expect.
How long does weed stay in your system and what does that mean for drug tests?
A whole industry has grown up catering for people trying to pass drug tests. Everything from synthetic urine with a fake penis delivery system, to dietary supplements have been used. Much of the time, efforts to evade THC detection work on the theory of dilution. Basic urine checks are fooled if the user has consumed large quantities of water prior to the test. But advanced urine tests can check to see if the sample is over-diluted and reject it.
Other drug test evasion techniques require you to add small amounts of chemicals such as vinegar, baking soda or lemon juice to the urine sample. These are scientifically proven ways to cheat a test. They will interfere with the chemical reaction used in the THC test. But again, more advanced urine test techniques can trace for the presence of deliberate contamination and reject the sample.
If your urine test isn't being supervised, you can simply provide urine from a non-cannabis using friend/relative or buy some powdered THC-free synthetic urine. If you are facing the possibility of being tested for weed use it helps to know more about how long weed really does stay in your system.
Key factors that influence the detection of THC and how long THC stays in your system
Several variables can affect how long weed stays in your system. These include your age, your cannabis consumption pattern and body mass index (BMI). These all have an impact on how your body processes and uses cannabis.
Other considerations include the type/potency of cannabis you use as well as how you use it. A heavy dose of cannabis that you have eaten (edibles) can be detected for longer than a one-off light vape. The amount and the frequency that you use weed will also affect how long THC stays in your system. If you use high quality, THC rich weed regularly, your body fats and bodily fluids will have easily detectable THC levels for longer periods than a user of lower doses of weaker weed.
How long THC stays in your system for different people (sex, age, fitness, hydration, metabolism...)
There are many questions related to how long THC stays in your system. In reality, the answer is different for each of us.
‘How long does THC stay in your system if you're a skinny guy?' will have a different answer compared to ‘how long does THC stay in your system if you’re overweight?’. Note that THC metabolites (THC-COOH) are stored in fatty tissues. Those with lower fatty tissue deposits, on average, have lower THC storage than those with higher levels of fatty deposits.
How long does weed stay in the system of an athlete? Usually less time than for an average person. That's because athletes tend to have the lowest levels of fatty tissue deposits. In addition, higher metabolic rates in athletes may lend themselves to faster breakdown of THC.
How long does THC stay in your system as a vegan? Much would depend on the individual, their levels of fatty tissue, their cannabis usage habits etc. Simply having a meat-free diet doesn't mean that THC leaves your system any quicker than it would for a meat eater.
Even the question ‘how long does THC stay in your system if you're a daily user?’ is difficult to give a definitive answer to. Some daily users smoke weed all day every day, others will only have a small daily vape in the evening to help them sleep.
Many have asked 'how long does THC stay in your system?' and if a calculator can determine the precise answer for their specific size, usage etc. But without detailed metabolic studies and fatty tissue analysis on each individual it’s impossible to create a calculator that will provide an accurate answer.
Maintaining good levels of bodily hydration is a key part of good health. But for cannabis users concerned about possible THC testing, good hydration is especially important since many of the ways used to defeat lower-tech THC tests require plenty of hydration to dilute the THC levels below detection limits.
Since CBD isn't psychoactive, few people worry about how long CBD stays in your system. Drug test companies, so far, haven’t made it a priority to catch CBD users.
How long does THC stay in your system for different consumption methods?
For any cannabis user facing a potential THC test, knowing roughly how long THC stays in your system is important. But does the way you consume THC affect how long THC really stays in your system?
‘How long does THC oil stay in your system?’ and ‘how long do THC edibles stay in your system’ may well have a different answer to the question of ‘how long does THC stay in your system after one puff’. A single inhalation of a vape or joint may just give you a few (e.g. 10) mg of THC. This is quicker for the body to metabolise than someone who took a 500mg THC edible or a gram of cannabis oil. No matter whether you enjoy your THC in gummies, wax pen, concentrates or dabs the THC will stay in your system. How quickly it disappears depends on you, your THC usage, metabolic rate, fatty tissue deposits and recent cannabis consumption habits.
THC stays in your system longer than hard drugs
One great irony of cannabis use is that, despite it being the least harmful of all recreational drugs, it remains the easiest to detect. That has led to years of unfair targeting of cannabis users. Many hard drugs have no medical benefits (in contrast to cannabis), yet are much more difficult to detect. This means that cannabis users have always been the easiest of all drug users to target, even though responsible adult use of cannabis is the least pressing ‘drugs problem’. Many would argue that truly responsible cannabis use is neither a drug problem nor the business of anyone else.
Frequency of use and cannabis dosage
Most cannabis users have different usage levels. This greatly complicates the simple question of how long does THC stay in your system. Daily cannabis users can have radically different cannabis consumption rates even though they may be all classified, rather alarmingly, as ‘chronic users’. A pensioner that uses a small pinch of weed each night in a vaporiser to assist sleep will have substantially lower THC levels in their system compared to a medical cannabis user that smokes heavily and regularly throughout the day.
Drug test sensitivity / accuracy
Drug tests from different suppliers all have different levels of sensitivity. The most advanced THC urine tests can measure other chemicals in urine to assess whether the user has recently consumed ‘excessive’ levels of water. ‘Dilution’ is the most common way to defeat lower tech urine tests, though it can be useless against higher tech THC urine tests.
This makes it difficult for the average cannabis consumer to be able to anticipate which type of test they will face, and how best to defeat it.
Many of those employed by the certain Government departments face regular THC testing. One of the favoured options to defeat THC urine tests is the ‘Whizzinator’. This is a false penis kept in your underwear for any urine test where you will be watched as you give the sample. The Whizzinator silently produces a perfectly safe ‘urine’ sample and even comes in different skin colours to defeat the most over-zealous drug testers that may be monitoring you.
How long does THC stay in your system for driving?
Drug driving is something that many cannabis users are very aware of. That’s one reason why regular cannabis users tend to show extra diligence and care when driving. After all, no-one wants to be involved in a road traffic accident which wasn't their fault, only to lose their license because the THC test found traces of a joint they enjoyed a few days previously.
THC impaired driving is a controversial subject. Especially because studies have shown conflicting results about THC and road safety. Combined with this is the fact that it is scientifically difficult to show that, at the time of the accident, the driver was impaired by the psychoactive effects of THC.
Presence of THC may be detectable a month or two after the person last used cannabis, but this doesn't mean that their driving ability was still impaired weeks later. That hasn’t stopped countries like Germany imposing draconian drug driving laws with a zero tolerance to THC. In Germany, just 1 nanogram of THC per ml of blood is sufficient to get you in serious trouble. The wiki page on THC and driving impairment is essential reading and shows a messy range of approaches and laws which have evolved around the world.
Of course, the responsible cannabis user tends to relax at home with a joint rather than drive around town smoking one whilst breaking speed limits and driving disrespectfully in full view of bored traffic cops. But being caught accidentally and being banned from driving remains a real fear for many regular cannabis users.
Can other cannabinoids than THC show on a drug test?
No, usually the chemists at the drug test companies focus their efforts on detecting THC and its metabolites.
How to get THC out of your body faster?
Unfortunately if you are facing an imminent drugs tests there is no simple, effective and 100% foolproof way to get THC out of your body faster. Because THC and its metabolites are stored in fatty tissues, removal of it is regarded as a process rather than an event.