Using activated charcoal to clear your system of THC and its metabolites is still controversial. Here is the science showing why it works.
I have focused so much recently on busting drug testing myths, that it is time to get down to some things that actually work. Today I will focus on a strategy to beat cannabis drug tests that has the reverse problem…many people don’t believe it even though it is proven to work!
I am talking about activated charcoal. Activated charcoal is a very porous type of carbon. It has a large surface area to which drugs will adsorb. It is frequently used in the emergency room to soak up drugs like a sponge in the GI tract in cases of poisonings and overdoses. It is also available over the counter as a powder, in capsules, and in drinks.
It might not hurt to keep some activated charcoal around in case you accidentally take too high a dose of edibles. Without a doubt it is effective at stopping drugs still in your intestines from being absorbed. But when it comes to drug testing, nobody can agree on whether it works!
There is so much misinformation! Vice tried to investigate it, but the expert they consulted got it wrong:
“As for the activated charcoal pills, it turns out that I may have been led astray by the internet…he told me that, basically, they’re bunk.
Herb suggests that it works, listing it as something that can be done a few days before the test:
“Some additional helpful supplements to try a few days before a test include…activated charcoal (only if the THC is still in your digestive tract)”
What the f*** are they even talking about? If you know you have a drug test coming up in a few days, why would you be taking an edible?
Even on a number of websites where physicians answered this question, they all gave wrong information:
“If you are asking if taking charcoal in order to pass a drug test – there is no basis to believe that this would have any significant effect on the levels or length of detection of common drugs in urine, hair or saliva tests”
Most of this confusion comes from a lack of knowledge about the properties of THC metabolites. That is why I am here to drop some science and set the record straight.
Enterohepatic Recirculation of THC Metabolites
The fundamental misunderstanding about whether activated charcoal works comes down to one question. After THC has been completely absorbed, do its metabolites go into the GI tract where they can be absorbed by the activated charcoal? Most people think that’s not possible, but the answer is yes. The reason why: enterohepatic recirculation.
After you ingest cannabis, your body converts THC to the THC-COOH metabolite and then the THC-COO-glucuronide metabolite. The addition of the glucuronide is like a tag that targets the metabolite to be removed from your body. It is excreted into your urine and is the primary metabolite detected in drug tests.
It is also sent into the bile by your liver. Two studies (here and here) have tested the bile of cadavers for THC and metabolites. The THC-COO-glucuronide metabolite was found in incredibly high levels in the bile with a median concentration of 17 uM. Your body produces about 600 mL of bile every day, so this is the equivalent of about 3 mg of THC excreted into your GI tract on a daily basis.
What happens to the metabolite once it is in your bile? Upon eating a meal, your body secretes bile into the GI tract. Since glucuronide metabolites are large and polar, they cannot be reabsorbed from the intestine. The idea is that it will be excreted in your feces. However, thanks to enzymes produced by the bacteria in your gut, most of the THC-COO-glucuronide is converted back to THC-COOH. The THC-COOH metabolite is then reabsorbed into the blood, where it can start the entire cycle over again.
This quantity of THC metabolites circulating through your bile and intestines represents a significant store that is completely separate from the commonly known fat storage. However, unlike the THC metabolites in fat that are basically inaccessible, we can use activated charcoal to interrupt this recirculation and clear the THC metabolites from our bodies. Once activated charcoal binds the metabolites, then they cannot be reabsorbed and you will poop them out.
Does Activated Charcoal Bind THC?
One obvious prerequisite for activated charcoal to work is that it needs to bind THC metabolites. One study assessed this and showed that it does. 5 mg of activated charcoal was able to completely bind 1 mg of either the THC-COOH or THC-COO-glucuronide metabolites (and maybe even more, but they only tested up to 1 mg).
Dietary fiber (in the form of wheat bran) was also able to bind these metabolites. Although an appealing alternative to activated charcoal, a lot more was required – even 250 mg of wheat bran was not able to bind all of the THC metabolites. Fiber also did not bind the glucuronide metabolite as well as THC-COOH.
Clinical Evidence that Activated Charcoal Removes THC Metabolites
Based on the above information, we have a strong, although theoretical, reason to use activated charcoal. But it gets better…a full clinical study was conducted just to see the effects of activated charcoal on THC metabolites. It does not get any better than this!
Eight subjects were dosed intravenously with the THC-COOH metabolite on two occasions. They were randomly assigned to receive the first dose with or without activated charcoal and then crossed over to the other condition on the second dose.
They dosed 5 g of the activated charcoal at 6 different timepoints: 15 min before the THC-COOH dose and 5 min, 2, 4, 7 and 10 h after the dose (for a total of 30 g charcoal).
By 24 hours after the dose, the serum THC-COOH concentrations were 45% lower when subjects were treated with activated charcoal. I suspect that if activated charcoal was given continuously, rather than just for the first 10 hours, the concentrations would have continued to separate further.
The amount of THC-COO-glucuronide excreted into the urine was reduced 21% with the activated charcoal treatment. THC-COO-glucuronide also reached undetectable levels in urine a full day earlier with activated charcoal.
Again, this is after just a single day of activated charcoal dosing. I expect results would be even better with multiple days of dosing.
Using Activated Charcoal to Clear Your Body of THC Metabolites
Here is my recommended regimen of activated charcoal to reduce levels of THC metabolites and prepare for a drug test:
- Take 10 g prior to each meal of the day (a total of 30 g a day).
- Activated charcoal carries a risk of constipation. Take it with plenty of water.
- If you do experience constipation or other side effects, you can reduce the dose to 5 g prior to each meal.
- Take the activated charcoal for 2 consecutive days each week, and then take a 5 day break.
- On the days that you do not use the activated charcoal, eat meals with a lot of fiber or take fiber supplements.
- Repeat this regimen from the time you want to detox until the time of the drug test. The more time you have, the better.
- Activated charcoal may bind to medications and dietary supplements and prevent their absorption. Consult your physician if you take medications.
Last modified: May 2, 2017