11-Hydroxy-THC (11-OH-THC) is a primary metabolite of delta-9-tetrahydrocannabinol (THC), the main psychoactive compound in cannabis. It significantly influences cannabis effects, especially when consumed orally. It explains unique characteristics of edible cannabis experiences.
How it Forms in the Body
The transformation of THC into 11-hydroxy-THC primarily occurs in the liver. THC undergoes a metabolic process involving specific liver enzymes from the cytochrome P450 family. The enzymes CYP2C9 and CYP3A4 are notably involved in this conversion.
This process, known as hydroxylation, modifies the THC molecule by adding a hydroxyl group. The resulting 11-hydroxy-THC is then further metabolized into other compounds, such as 11-nor-9-carboxy-THC (THC-COOH), which is inactive. This metabolic pathway is important for making cannabinoids more water-soluble, which facilitates their excretion from the body.
Its Unique Effects
11-hydroxy-THC produces more intense psychoactive effects than delta-9 THC. This heightened potency is partly due to its increased ability to cross the blood-brain barrier more readily than delta-9 THC. Once it reaches the brain, 11-hydroxy-THC interacts with cannabinoid receptors, leading to pronounced cognitive and perceptual effects.
While 11-hydroxy-THC is an active metabolite, it exhibits a similar efficacy to delta-9 THC in its interaction with CB1 receptors. When administered intravenously, 11-hydroxy-THC results in a faster onset of effects compared to THC. Its effects can also last for several hours, contributing to a longer overall duration.
Why it Matters with Edibles
Oral cannabis consumption, like edibles, undergoes “first-pass metabolism” in the liver. Before THC enters the bloodstream, liver enzymes metabolize a significant portion. During this first pass, a much higher concentration of THC is converted into 11-hydroxy-THC compared to other consumption methods like smoking or vaping.
Increased 11-hydroxy-THC production explains why edibles lead to a more intense, delayed, and prolonged experience. Edibles typically take 30 minutes to 2 hours to produce effects, with peak levels occurring between 1 to 2.5 hours, and the effects can last anywhere from 4 to 12 hours. This contrasts with inhaled cannabis, which bypasses the extensive first-pass metabolism and delivers THC directly to the bloodstream and brain, resulting in a quicker onset but often a shorter duration.
Implications for Drug Testing
11-hydroxy-THC can be detected in various biological samples, including blood and urine. While THC-COOH, an inactive metabolite, is the primary target for cannabis drug tests due to its longer detection window, 11-hydroxy-THC also indicates recent cannabis use. Its presence, particularly in certain types of tests, can help differentiate between recent consumption and past exposure.
In some legal contexts, the levels of 11-hydroxy-THC, alongside THC and THC-COOH, are used to assess recent cannabis use and potential impairment. For instance, if both 11-hydroxy-THC and THC-COOH are present, it suggests more recent consumption, whereas the presence of only THC-COOH indicates use that occurred some time ago. New legislation in some areas is also considering the use of psychoactive markers like 11-hydroxy-THC in workplace drug testing.