11-Hydroxy-THC (11-OH-THC) is the primary active metabolite of Delta-9-tetrahydrocannabinol (Delta-9-THC), the main psychoactive component found in cannabis. This compound is produced by the body after cannabis consumption. 11-OH-THC is highly active and is responsible for a significant portion of the intoxicating effects experienced by users, particularly when consuming edibles.
How the Body Creates 11-Hydroxy-THC
11-OH-THC creation occurs mainly within the liver. When Delta-9-THC enters the bloodstream, it is quickly directed to the liver for metabolic processing. Here, the THC molecule undergoes oxidation, facilitated by cytochrome P450 enzymes.
The conversion is primarily carried out by two specific enzymes: Cytochrome P450 2C9 (CYP2C9) and Cytochrome P450 3A4 (CYP3A4). These enzymes introduce a hydroxyl group onto the THC molecule at the 11th carbon position, transforming Delta-9-THC into 11-OH-THC. This new compound retains psychoactive properties.
The metabolic pathway continues as 11-OH-THC is further oxidized. This next step converts it into 11-nor-9-carboxy-THC (THC-COOH), which is an inactive compound. THC-COOH is then made water-soluble through glucuronidation, preparing it for excretion from the body through urine and feces.
Psychoactive Power and Intensity
The 11-OH-THC metabolite has a high potency compared to Delta-9-THC. It can be up to three times more psychoactive than the original compound. This enhanced effect is due to its improved ability to interact with the body’s endocannabinoid system.
The chemical structure of 11-OH-THC allows it to cross the blood-brain barrier more efficiently than Delta-9-THC. This allows a higher concentration of the psychoactive compound to reach the brain’s receptors. 11-OH-THC shows a higher binding affinity for the CB1 receptors, which are the main targets for psychoactive effects.
For the user, this translates to an experience often described as more intense, sedative, and “body-heavy” than the high felt from inhaled cannabis. While inhaled THC provides a rapid peak that tapers quickly, 11-OH-THC contributes to a high that takes longer to begin but generally lasts much longer, sometimes for four to eight hours.
Why Consumption Method Matters
The route of consumption determines the concentration of 11-OH-THC in the bloodstream. When cannabis is inhaled (smoked or vaped), Delta-9-THC enters the lungs and is absorbed directly into the systemic circulation. This rapid absorption bypasses the liver initially, meaning only a small fraction of THC is converted to 11-OH-THC before reaching the brain.
Orally consumed cannabis, such as edibles, must first travel through the digestive system. Once absorbed from the gut, the THC-rich blood is routed directly to the liver before entering the main circulatory system. This phenomenon is called “first-pass metabolism.”
During first-pass metabolism, a much greater amount of Delta-9-THC is subjected to the CYP450 enzymes and converted into 11-OH-THC. This results in a significantly higher ratio of the potent 11-OH-THC metabolite reaching the brain. This explains why edibles have a delayed onset but deliver a substantially more potent and prolonged psychoactive effect.
Detection in Drug Testing
Standard drug tests do not typically target 11-OH-THC as the primary indicator of cannabis use. Instead, these screens look for the presence of the inactive metabolite, THC-COOH. THC-COOH is highly stable and can remain detectable in urine for weeks after use, making it the preferred marker for past exposure.
The presence of 11-OH-THC is a strong indicator of very recent consumption. Because 11-OH-THC is quickly metabolized further into inactive THC-COOH, its window of detection is relatively short, often only a few hours in blood. Specialized forensic or impairment testing may look for 11-OH-THC because its presence confirms the body is currently processing the psychoactive substance.