11-Hydroxy-THC: The Metabolite Behind Edibles | PatientsCann UK

11-Hydroxy-THC

11-OH-THC, 11-hydroxy-delta-9-THC

pronounced: ih-LEV-uhn hy-DROK-see tet-ruh-hy-droh-kuh-NAB-ih-nol

The stronger metabolite your liver makes from THC. It is the reason eaten cannabis can feel so much more intense.

Metabolite (body-made)Formula: C21H30O3Intoxicating: Yes, stronger
Type
Metabolite
Formula
C21H30O3
Intoxicating
Yes
Key focus
Edibles

11-Hydroxy-delta-9-THC · 330.5 g/mol

The molecule

Chemical structure

This is the accurate skeletal structure of 11-hydroxy-THC, drawn from PubChem data. It is almost identical to THC, but your liver has added an oxygen and hydrogen (an -OH group) at one end. That tiny change makes it stronger. Its formula is C21H30O3 and it weighs 330.5 g/mol.

Stronger than THCLong-lastingReaches brain fastEdible effects

About

What is 11-Hydroxy-THC?

11-Hydroxy-THC is a metabolite. That means it is not made by the plant. Instead, your own body makes it in the liver when it starts to break THC down. Its full name is 11-hydroxy-delta-9-tetrahydrocannabinol, usually shortened to 11-OH-THC.

Here is the surprising part: it is stronger than THC itself. Research suggests it is somewhere between 1.5 and 7 times more active at the CB1 receptor, and it slips into the brain more easily. So the molecule your body makes can pack more of a punch than the one you started with.

In the body

How 11-Hydroxy-THC Works

Like THC, 11-hydroxy-THC works by switching on the CB1 receptor in the brain and nerves. But because it fits that receptor even better and crosses into the brain more readily, the effects can feel stronger and last longer.

This is the hidden reason an edible can feel so different from a vape. When cannabis is eaten, a large share of the THC is turned into 11-hydroxy-THC before it ever reaches the rest of your body. When it is inhaled, far less is made.

Receptor snapshot

Where 11-Hydroxy-THC Acts

The endocannabinoid system has two main receptors. Here is how strongly 11-hydroxy-THC acts on each.

CB1Brain & nervous system
Very strong

Fits CB1 even better than THC. This is what makes it more potent, and why eaten cannabis can feel so intense.

CB2Immune system & body
Partial

Also acts on CB2 in the immune system, much like THC does.

Why it matters: after an edible, blood levels of 11-hydroxy-THC can be as high as, or higher than, THC itself. After inhaling, there is far less. This is the main reason the two routes feel so different.

In the body

How 11-Hydroxy-THC is Made

When you swallow cannabis, it travels to the liver before reaching the rest of your body. This is called first-pass metabolism. A liver enzyme called CYP2C9 adds an oxygen to THC, turning it into 11-hydroxy-THC.

Your body then oxidises it again into the inactive THC-COOH, which is later flushed out. How fast all of this happens differs a lot from person to person.

PathwayTHC→ liver →11-OH-THC→THC-COOH

Good to know

Safety and Side Effects

Because 11-hydroxy-THC is stronger, edibles can catch people out. The onset is slow, often 30 minutes to 2 hours, so it is easy to think a dose "isn't working" and take more. When both doses land together, the effect can be overwhelming, with anxiety, a racing heart or feeling faint.

The golden rule with edibles is to start low, go slow, and wait at least 2 hours before considering any more. It affects driving. Always follow your prescriber's advice.

Questions

11-Hydroxy-THC: Common Questions

Why do edibles feel stronger than smoking?
When you eat cannabis, your liver changes most of the THC into 11-hydroxy-THC before it reaches the rest of your body. This metabolite is stronger than THC and reaches the brain more easily, so an eaten dose can feel much more intense and last longer than an inhaled one.
Is 11-hydroxy-THC found in the cannabis plant?
No. 11-hydroxy-THC is not made by the plant. It is a metabolite, which means your own body makes it in the liver while breaking down THC, mostly using an enzyme called CYP2C9.
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Important: This page is for education only. It is not medical advice. Cannabinoid research is still developing, and many studies have been done in cells or animals rather than people. Always speak to your prescriber before changing your treatment. PatientsCann UK does not recommend any specific cannabis product.

References

  1. Huestis, M.A. (2007) 'Human cannabinoid pharmacokinetics', Chemistry & Biodiversity, 4(8), pp. 1770-1804. doi: 10.1002/cbdv.200790152.
  2. Grotenhermen, F. (2003) 'Pharmacokinetics and pharmacodynamics of cannabinoids', Clinical Pharmacokinetics, 42(4), pp. 327-360. doi: 10.2165/00003088-200342040-00003.
  3. Sachse-Seeboth, C. et al. (2009) 'Interindividual variation in the pharmacokinetics of delta-9-tetrahydrocannabinol as related to genetic polymorphisms in CYP2C9', Clinical Pharmacology & Therapeutics, 85(3), pp. 273-276. doi: 10.1038/clpt.2008.213.
  4. National Center for Biotechnology Information (2025) PubChem Compound Summary for CID 37482, 11-Hydroxy-Delta9-THC. Bethesda: U.S. National Library of Medicine. Available at: https://pubchem.ncbi.nlm.nih.gov (Accessed: 3 August 2026).