THC Metabolism

Last Updated on Mon, 08 Jul 2024 | Marijuana Studies

The amount of time required to metabolize THC has shown considerable variation from person to person and study to study. The period required to eliminate THC from the body should not be confused with the duration of the drug's psychoactive effects. People stop feeling high long before THC has left their bodies. Intoxication rarely last more than a few hours, with orally administered doses lasting longer than smoked cannabis. After an intravenous injection of THC, blood levels peak almost immediately and then decrease by 90% in the first hour. This rapid drop does not mean that the drug has exited the body; it simply leaves the blood to dissolve into fat tissue. THC in the blood partitions into fat tissue, then leaks slowly from fat to be degraded and excreted. Although media accounts of marijuana's effects often treat THC's fat solubility as a novelty, sedatives like the barbiturates and benzodiazapines are stored in fat, too. After the first hour, blood levels of THC do not drop as rapidly. As THC from the blood is eventually excreted in urine and feces, THC stored in fat returns to circulation, but in doses too small to create psychoactive effects.

Researchers express the time required to metabolize a drug as its half-lifea€"the period required to break the dose down to 50% of its original amount. Suppose the half-life of a hypothetical drug was one day. People who absorbed 100 mg of this drug would reduce it to 50 mg in one day. The next day they would again cut the available dose in half, to 25 mg. The next day would decrease the amount to 12.5 mg, and so on. Zeno's paradox would suggest that this consistent splitting in two would actually never lead to a blood level of zero. The amount would decrease by 50% repeatedly, growing smaller and smaller, but it would never disappear. Practically, drugs reach an undetectable concentration after 4.5 or 5 half-lives (Diaz, 1997).

Estimates of the half-life of THC based on urinary excretion show incredible variation. Research estimates of THC's half-life range from as little as 19 hours (Hunt & Jones, 1980) to as much as 4 days (Johansson, Arguell, Hollister, & Halldin, 1988). Early work suggested that users might grow more efficient at metabolizing THC as they gain experience with the drug (Lemberger, Axelrod, & Kopin, 1971). This study found a half-life of 28 hours for chronic smokers, but naive users took 57 hours to metabolize half of the dose. These results had considerable intuitive

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appeal because they helped explain marijuana tolerance. The authors of this research implied that people grew tolerant to the drug because they essentially eliminated it more readily.

In contrast to evidence of increased rates of metabolism in experienced users, a later study found that people who had received THC each day for two weeks did not metabolize faster than moderate users who had not ingested daily doses (Hunt & Jones, 1980). In addition, the study with the longest estimated half-life used chronic, regular smokers (Johansson et al., 1988). These results seem confusing in light of the previously reported shorter half-life for heavier users. Thus, THC's rate of metabolism may not increase with repeated use. Most studies show a half-life between 1 and 1.5 days (Ohlsson et al., 1982; Ohlsson et al., 1985; Wall et al., 1983). A recent study using an extremely sensitive measuring technique and a two-week follow-up period found THC half-life ranges up to 2.5 days (Huestis & Cone, 1998). This study used the best methods available and suggests that a dose of THC leaves the body completely after 12 or 13 days.

The extreme variation in the estimates for the half-life of THC may stem from studying small samples of people over relatively short durations, using measurement techniques that vary in sensitivity. This large range of estimates likely reflects individual differences among people. Some simply metabolize more quickly than others. Techniques that do not rely on urine samples suggest THC stays in the body even longer. Analysis of fat cells rather than urine samples has revealed that the drug can remain in the body up to a month in some people (Johansson, Noren, Sjovall, & Halldin, 1989). Popular authors imply that this long elimination period is the norm (DuPont, 1984), but many people metabolize THC faster. Despite all the variability in elimination periods, marijuana does appear to have a longer half-life than some other drugs. For example, nicotine's half-life is about 2 hours; caffeine's is 3 to 6 hours (Henningfield, Cohen, & Pickworth, 1993). However, some sedatives that are more fat soluble show half-lives around 2 days or more (Diaz, 1997). Thus, marijuana takes more time to metabolize than some drugs, but less than others.

Popular authors often misinterpret THC's long half-life by frequently implying that intoxication or some sort of residual effect of the drug remains for weeks at a time. Yet intoxication dissipates in a couple of hours. The amount of THC released gradually from fat cells does not create any subjective, cognitive, or emotional effects but may register on

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drug tests. Thus, a person may test positive for cannabis even a week or two after smoking, when all signs of intoxication have clearly terminated (Zimmer & Morgan, 1997). A number of underground legends suggest that goldenseal, cranberry juice, or various other concoctions might shorten this period of testing positive; no systematic research addresses this question. Drinking enormous quantities of fluids may dilute THC metabolites in the urine and alter the outcome of a test, but these fluids do not actually alter metabolic rate (Coombs & West, 1991).

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Readers' Questions

  • William
    How is marijuana metabolised?
    10 months ago
    • Marijuana is metabolized in the body through a process known as hepatic metabolism. When THC (tetrahydrocannabinol), the main psychoactive component of marijuana, is consumed, it is first absorbed into the bloodstream through the lungs (when smoked) or the digestive system (when ingested). From there, THC is carried to the liver, where it is metabolized by enzymes. The primary enzyme responsible for this process is called cytochrome P450, specifically CYP2C9 and CYP3A4. These enzymes break down THC into various metabolites, including 11-hydroxy-THC and 11-nor-9-carboxy-THC (THC-COOH). 11-hydroxy-THC is formed when THC is processed by the liver, and it is believed to be more potent and have stronger psychoactive effects than THC itself. On the other hand, THC-COOH is the main metabolite detected in drug tests and is responsible for the long detection window of marijuana in the body. Once metabolized, these THC derivatives and other metabolites are further broken down and eliminated from the body through urine and feces. The elimination half-life of THC-COOH, which determines how long it takes for half of the THC to be eliminated, is quite long, ranging from a few days to a few weeks, depending on factors such as the frequency of use, dosage, individual metabolism, and other factors.
    • sirkka forssell
      Which way metaboluzes the fastest injecting smoking?
      11 months ago
      • Injecting a substance is generally faster than smoking it. When a substance is injected, it directly enters the bloodstream, bypassing the digestive system and liver. This allows for faster absorption and metabolism. On the other hand, smoking involves inhalation of the substance, which then enters the bloodstream through the lungs. Although this method is still relatively fast, it may take a bit longer for the substance to be metabolized compared to injection. It is important to note that the rate of metabolism can also depend on factors such as the specific substance being used, individual metabolism, and other variables.
      • pandora mugwort
        What form of marijuana use metabilizes quicker in the body?
        1 year ago
        • The form of marijuana use that metabolizes the quickest in the body is inhalation, particularly smoking or vaporizing the substance. When marijuana is smoked or vaporized, the active compounds such as THC (delta-9-tetrahydrocannabinol) enter the lungs and rapidly absorb into the bloodstream. This allows for relatively quick onset and metabolization within the body. However, it is important to note that the exact rate of metabolism can vary depending on various factors such as individual metabolism, potency of the product, and frequency of use.
        • DENNIS FARBER
          How quickly do cannabis metabolites leave your body 50% per week?
          1 year ago
          • The exact rate of how quickly cannabis metabolites leave your body can vary depending on an individual's metabolism, frequency of use, and other factors. Generally, it is thought that it takes about a week for about 50% of the cannabis metabolites to leave your body.
          • johan ukkonen
            How long does it take to metabolize marijuana THC9 out of your system?
            1 year ago
            • The exact amount of time it takes to metabolize marijuana THC out of your system depends on a variety of factors, including your age, body weight, activity level, genetics, and overall health. Generally, it takes 3-4 days for THC metabolites to be eliminated from the body after occasional use and up to 30 days for chronic, heavy users.
            • demi
              How fast do thc and marijuana concentrations decline?
              1 year ago
              • The rate at which THC and marijuana concentrations decline depends on many factors, including storage temperature, method of consumption, amount of time passed since consumption, amount of marijuana used, and individual metabolism. Generally, marijuana concentrations decline at different rates for THC and other plant compounds. THC concentrations tend to decrease over time more quickly than other compounds.
              • asmara elias
                Can some humans process thc faster than others?
                1 year ago
                • Yes, some humans can process THC faster than others. This is largely due to genetic differences and individual metabolism. As THC is broken down by the liver, individuals with different enzyme production levels may process THC differently. For example, individuals who lack the enzyme CYP2C9 may process THC more slowly. On the other hand, individuals who have increased CYP2C9 activity may process THC more quickly.
                • GIMJA
                  How fast does marijauna metabolize?
                  1 year ago
                  • Marijuana typically metabolizes at an average rate of between 1 and 10 days, depending on the individual's metabolism and the amount of marijuana consumed.
                  • henriikka lintula
                    How does marijuana metabolize in the body?
                    1 year ago
                    • Marijuana is metabolized in the body in a two-step process. First, the primary active component of marijuana, delta-9-tetrahydrocannabinol (THC), is metabolized by the liver into 11-OH-THC, which is more active and more psychoactive. This metabolite is then further broken down by the body into metabolites that are inactive, including metabolites like 11-nor-9-carboxy-THC, which are excreted in the urine.
                    • anu
                      How many metabolites of thc are excreted each day?
                      1 year ago
                      • The exact amount of THC metabolites excreted each day can vary greatly depending on the individual and how often they have used cannabis. Generally, it is estimated that an individual may excrete up to 10-50 milligrams of THC metabolites per day.
                      • juliane
                        How much thc metabolites are produced with resin hits?
                        1 year ago
                        • The amount of THC metabolites produced with resin hits varies greatly, depending on the product and method of consumption. Resin smoking can produce a range of levels of THC metabolites from low to high levels.
                        • james
                          How are thc metabolites released in the urine?
                          1 year ago
                          • THC metabolites are released in urine through metabolic processes. These processes involve the conversion of THC into various metabolites, including 11-nor-Δ9-THC-9-carboxylic acid (THC-COOH), which is then excreted in the urine.
                          • tim
                            How fast do levels of thc metabolites fall?
                            1 year ago
                            • It depends on several factors including the amount and frequency of cannabis use, the method of consumption, body fat content, and metabolism rate. In general, detectable levels of THC metabolites usually decline within seven days for occasional users and up to 30 days for heavy users.
                            • dieter klein
                              Does thc metabolize after death?
                              1 year ago
                              • No, THC does not metabolize after death. THC is stored in fatty tissue of the body and is only released during metabolic processes. After death, no metabolism takes place, so the THC remains stored in the body.
                              • Marina
                                How much thc metabolizes into hair?
                                1 year ago
                                • The amount of THC metabolized into hair varies from person to person, as well as the length of time the THC has been in the body. Therefore, it is impossible to give an exact number. However, there have been studies that show the presence of THC metabolites in hair follicles, suggesting that some THC does metabolize into the hair.
                                • lisa
                                  How fast does marijuana metabolize in the blood after being drawn?
                                  1 year ago
                                  • Marijuana can typically be detected in the bloodstream within a few minutes of inhalation and can remain in the bloodstream for up to 12 hours.
                                  • danielle guzman
                                    How fast to metabolize marijuana?
                                    1 year ago
                                    • The rate at which marijuana is metabolized in the body varies from person to person and depends on several factors, such as the person's age, body mass, genetics, and amount and frequency of use. Generally, the average amount of time it takes for marijuana to be metabolized and eliminated from the body is 3-4 days.
                                    • Emilia
                                      How fast does thc metabolize to from blood to urine?
                                      1 year ago
                                      • The metabolism of THC can vary greatly depending on the individual, but the average estimated rate of elimination from the body is around one week.
                                      • nebay
                                        Do some people metabolise thc faster than others?
                                        1 year ago
                                        • Yes, some people can metabolize THC faster than others. Factors like body mass index, metabolism rate, age, gender, and frequency and amount of THC use can all influence a person's ability to metabolize THC.