11-OH-THC is formed in high levels after taking edibles. Here is the history and science behind the discovery that it is even more potent than THC.

Out of the dozens of different cannabinoids, I believe that 11-OH-Δ9-tetrahydrocannabinol (abbreviated 11-OH-THC) is one of the most interesting.

Why? First, it is highly psychoactive. In fact, it is just as psychoactive as the famous THC molecule, if not more so (we’ll get to this a little later).

Second, 11-OH-THC does not naturally exist in the cannabis plant, but is formed within the human body after ingestion of THC. The amount of 11-OH-THC formed in your body can vary wildly depending on whether you take cannabis as an edible (high levels) or smoke it (low levels).

THC to 11-OH-THC metabolism

Metabolism of THC to 11-OH-THC

We all know that edibles give a different type of high than smoking. One intriguing explanation is that different levels of 11-OH-THC formed is the reason why.

THC metabolism and formation of 11-OH-THC

After THC is ingested, your liver goes to work on it, converting it into other molecules in order to eliminate it from your body. These other molecules are called metabolites. Usually metabolites are less active than the parent molecule, but sometimes you get one that is even more potent!

What is especially interesting about THC metabolites is that their levels in your body can be more than 10 times higher if you take cannabis in an edible form rather than through other routes (for example, smoking or vaping).

Why do edibles form so much more 11-OH-THC than smoking? There are two factors.

The first is that the drug-metabolizing enzymes are present in your GI tract. As you are sitting there digesting that cannabis brownie, these enzymes are busy creating 11-OH-THC.

The second factor is that all blood flow from your GI tract goes to the liver first before entering the general circulation (a phenomenon called first pass metabolism). This is one more chance for 11-OH-THC to be created in high quantities.

first pass metabolism

11-OH-THC is formed in the gut and liver from THC

On the other hand, when you smoke cannabis, THC is absorbed directly through the lungs, where little metabolism takes place. The THC quickly distributes to other body tissues and only a small fraction of it remains in the blood. The THC that remains in your blood is available to go to the liver and be converted to 11-OH-THC and other metabolites. However, the larger fraction in other tissues is not metabolized and so not much 11-OH-THC is formed overall.

The levels of 11-OH-THC in your blood after smoking cannabis are only about 5% of THC levels. This is probably not enough to feel any effects from the 11-OH-THC.

However, after taking cannabis orally, the average levels of 11-OH-THC vary from 25% of THC to more than 300% of THC levels, depending on which study you look at. These are just averages of a group of people – there is even further variation at the level of individuals. So some people will have well over 3 times more 11-OH-THC in their body than THC after ingesting cannabis!

Ratios of THC to 11-OH-THC are approximated from multiple studies

These results show that THC may not be the most important molecule after taking edibles. But how do the psychoactive effects of 11-OH-THC compare to THC?

There seems to be a lot of misinformation about the effects of 11-OH-THC on the internet. I saw people claiming that the effects of 11-OH-THC are 10 times stronger than THC. Let’s see how accurate these claims are by taking a stroll through some scientific history.

The History of 11-OH-THC Research

The early ’70s were a heyday for cannabinoid research. Many of the seminal studies were conducted during this period when we were just discovering for the first time the details of how cannabis works.

In 1970, radiolabeled THC was synthesized. You heard that right, they made radioactive THCI know what you are thinking and the answer is no. Radioactive THC does not get you super fucking high and it does not give you superpowers after you smoke it.

spidey joint

Radiolabeled THC actually behaves just like regular THC, except it allows scientists to more easily see how it is metabolized and where all these metabolites go (hint: mostly your poop). This study of radiolabeled THC was the first to show that 11-OH-THC was formed in humans.

There was already some controversy at this time about the relative activity of THC and 11-OH-THC. Some researchers even believed that THC was mostly inactive and that the psychoactive effects were due primarily to 11-OH-THC. If this were true, then we would classify THC as a prodrug – a drug that needs to be metabolized to be activated. 

At first, just small quantities of 11-OH-THC were available. The only option researchers had to answer these questions was doing animal studies of 11-OH-THC. The main problem with this approach was getting the rats to report on how stoned they were. Needless to say, these results were not convincing.

After larger quantities of 11-OH-THC became available, it was game on to see what happened in humans. Three seminal studies were performed over just a few years to characterize the effects of 11-OH-THC in humans. 

In the next section I’m going to go round by round to see who is the ultimate champion: THC or 11-OH-THC.

Scientific Throwdown: 11-OH-THC vs. THC

Round 1: 11-OH-THC Enters the Ring

These scientists went straight for the knockout with this study by pumping 11-OH-THC directly into the bloodstream via intravenous infusion.

“Between 2 to 3 minutes after the intravenous administration of 11-OH-THC, the psychologic high reached its peak and was of greater intensity than any they had previously experienced after taking marihuana.”

Right cross to the jaw! 11-OH-THC got people high as shit! Interestingly, the psychoactive effects of intravenous 11-OH-THC appeared to come on much quicker than after intravenous THC. This is most likely because 11-OH-THC can more rapidly cross the blood-brain barrier.

Round 2: THC Holds Its Own

Round 1 wasn’t completely fair, because THC was not even included in the study. In the next study, subjects received a slow infusion of either 11-OH-THC or THC. They were asked to report (1) when they first felt high and (2) when they reached their desired level of highness, at which point the infusion was stopped.

On one hand, subjects in the 11-OH-THC group stopped the infusion earlier than the THC group, saying they felt sufficiently high. On the other hand, the THC group felt higher overall.

There was no clear winner. This round was a split decision.

Round 3: 11-OH-THC Takes The Title

In the final study, the scientists used a fixed dose of THC and 11-OH-THC, again administered intravenously. They administered both drugs to the same subjects at different times, in a head-to-head battle of the cannabinoids to decide the champion.

After a 1 mg administration of both drugs, the final winner was….11-OH-THC! With this molecule, subjects reached nearly an 8 out of 10  on the  highness scale, vs. only about a 3 out of 10 for THC. Pound for pound (or at least mg for mg), 11-OH-THC was untouchable.


11-OH-THC with the knockout


The claim that 11-OH-THC is 10 times stronger than THC is not correct. 11-OH-THC seems to be more potent, but both molecules can probably get you just as high with a large enough dose.

It is likely that the high you get from edibles is due to a mix of both 11-OH-THC and THC. The qualitative aspects (for example, more psychedelic) of the 11-OH-THC high were not assessed in these scientific studies, so that is up to you to decide!

Last modified: May 30, 2017

3 Responses to " 11-Hydroxy-THC – Increased Potency That Explains the Effect of Edibles? "

  1. Mike says:

    What happens with suppositories?

  2. […] about the psychoactive metabolite 11-OH-THC? This metabolite is formed in high quantities after taking edibles. Rumor has it that 11-OH-THC can more easily get into the […]

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