HOW THC MOVES THROUGH THE BODY

HOW THC MOVES THROUGH THE BODY

When marijuana is smoked, the rich blood supply of the lungs rapidly absorbs the THC. This applies to marijuana that is "vaporized" as well. Even though it is not burned, the THC that is mobilized from the plant material in the vaporizer is absorbed through the lungs. Because blood from the lungs goes directly from the heart to the brain, the high, as well as the effects on heart rate and blood vessels, occurs within minutes. Much of the THC is actually gone from the brain within a few hours after smoking. However, THC also accumulates in significant concentrations in other organs, such as the liver, kidneys, spleen, and testes. THC readily crosses from the blood of a pregnant woman into the placenta and reaches the developing fetus.

How the smoker smokes makes a difference in how much of the THC from the marijuana actually gets to the body. A cigarette allows for approximately 10 to 20 percent of the THC in the marijuana to be trans­ferred. A pipe is somewhat more efficient, allowing about 40 to 50 percent to transfer, and a water pipe (or bong) is quite efficient. Because the water pipe traps the smoke until it is inhaled, theoretically the only THC lost is what the smoker exhales. Vaporizers allow a very efficient transfer of THC because, in addition to taking advantage of the rich blood supply in the lungs, vaporized pot does not create smoke that can be irritating to the lungs and cause a person to limit his inhalation or to cough out a "hit" that is too big. This can be a problem as well, particularly when a smoker first switches to a vapor system. Smokers are used to the feeling of smoke in their lungs and often use that feeling as a gauge by which they estimate their intake. The vapor does not irritate the lungs, so that gauge is missing and some new vapor users take in far more THC than they intend until they figure out a new way to estimate their intake.

Although much of the high wears off relatively soon after smoking, THC remains in the body much longer. About half of the THC is still in the blood twenty hours after smoking. And once the blood carrying the THC passes through the liver, some of the THC is converted into other compounds that may remain there for several days. Some of these metab­olites have psychoactive effects as well, so that although the initial high may disappear within an hour or two, some of the effects of marijuana on mental and physical functions may last for days.

Not only may THC and its metabolites stay in the blood for days but they also stay in the fatty deposits of the body much longer because they are very lipid-soluble—they easily get absorbed into and stored in fat. THC stored in fatty deposits is released from these tissues slowly over a rather long period of time before finally being eliminated. What all this means is that about 30 percent of ingested THC (and its metabolites) may remain in the body a full week after smoking and may continue to affect mental and physical functions subtly. In fact, the remnants from a single large dose of THC may be detectable up to three weeks later.

All of these rules also apply when marijuana is eaten instead of smoked, except that less THC gets to the brain and it takes a lot longer for it to get there. When marijuana (or any drug) is taken into the stomach, the blood that absorbs it goes to the liver before flowing to the rest of the body (including the brain). This means two things: First, the liver breaks down some of the THC before it ever has a chance to affect the brain. Second, the remaining THC reaches the brain more slowly because of its indirect route through the bloodstream. However, because the body absorbs THC more slowly when marijuana is eaten, the peak levels of the drug last lon­ger (though they are lower than they would be if the same amount were smoked).

Whether the user eats or smokes marijuana and the accompanying differences in the way THC is distributed and metabolized appear to have a substantial impact on the kind of experience he has. Rather than experiencing a sudden change from being straight to being high, the marijuana eater experiences a slow and gradual shift that lasts longer. Many experienced users report that what happens after eating marijuana is more reminiscent of a mild mushroom or LSD trip; it's not simply "getting high." Because high levels of THC can cause hallucinogen-like experiences, people who have eaten marijuana and reported such feel­ings may actually have achieved higher levels of THC than many smok­ers—despite the fact that some of it is metabolized by the liver before it gets to the brain—because they ate a larger amount than they would likely have smoked.