How Endocannabinoid Enzyme Inhibitors Are Revealing the Different Roles of Anandamide and 2-AG | Research

The takeaway

A comprehensive review detailed how FAAH and MAGL inhibitors are being used to tease apart the separate roles of anandamide and 2-AG in pain, anxiety, and addiction, revealing distinct therapeutic potentials for each pathway.

Read this if you want to understand the cutting edge of endocannabinoid-based drug development.

FAAH and MAGL inhibition produced different and sometimes opposite effects on anxiety

What the researchers found

The review described the development and application of chemical tools that selectively block the enzymes degrading each major endocannabinoid. FAAH inhibitors (boosting anandamide) and MAGL inhibitors (boosting 2-AG) have revealed that these two pathways serve different functions.

In pain models, both FAAH and MAGL inhibitors showed efficacy but through different mechanisms. In anxiety models, FAAH inhibition was anxiolytic while MAGL inhibition sometimes produced opposite effects. In addiction models, the two pathways had distinct roles in reward and withdrawal. The review emphasized that these differences have crucial implications for which pathway to target therapeutically.

Why it matters

Simply saying "boost endocannabinoids" is too imprecise. Anandamide and 2-AG have overlapping but distinct roles. This review mapped those differences, guiding the development of more targeted therapies that boost the right endocannabinoid for the right condition.

The numbers in context

Two primary endocannabinoids: anandamide (FAAH substrate) and 2-AG (MAGL substrate). Two primary degrading enzymes: FAAH and MAGL. Applications tested: pain, anxiety/depression, addiction. Different and sometimes opposite effects from boosting each pathway.

How the study worked

Comprehensive narrative review covering the pharmacological development of FAAH and MAGL inhibitors, their use in preclinical behavioral models, and the emerging understanding of differential anandamide vs. 2-AG function.

What this study cannot tell us

Most evidence came from rodent studies. Species differences in enzyme pharmacology (particularly for MAGL inhibitors) complicate translation to humans. Long-term effects of sustained endocannabinoid elevation remain poorly understood. Clinical trial data for these inhibitors was limited at publication.

How to read the evidence

Comprehensive review in a top pharmacology journal; strong synthesis of the preclinical evidence base.

When this study was published

Published in 2013. FAAH inhibitors have since entered clinical trials, though one major trial (BIA 10-2474) had a serious adverse event in 2016, slowing development.

The bigger picture

This review represents the maturation of endocannabinoid pharmacology from crude receptor-level intervention (like THC) to precision pathway-level modulation. The ability to selectively boost either anandamide or 2-AG opens a new therapeutic paradigm.

Questions still open

Will the differential roles of anandamide and 2-AG established in rodents translate to humans? Which conditions would benefit most from FAAH vs. MAGL inhibition? Can dual inhibitors provide benefits beyond single-pathway targeting?

Common questions

What is the difference between anandamide and 2-AG?

Both are endocannabinoids (natural cannabis-like molecules in the brain) that activate the same receptors, but they serve different functions. Anandamide is broken down by FAAH and appears more important for anxiety regulation. 2-AG is broken down by MAGL and plays a broader role in synaptic signaling. Blocking each enzyme produces different behavioral effects.

Why not just use cannabis instead of these inhibitors?

Cannabis (THC) activates cannabinoid receptors everywhere simultaneously, causing both therapeutic and unwanted effects. Endocannabinoid enzyme inhibitors boost the body's own cannabinoids only where and when they are naturally released. This more targeted approach could provide therapeutic benefits with fewer side effects, though the approach is still in development.

Read the original research

Chemical probes of endocannabinoid metabolism.

Pharmacological reviews, 65(2), 849-71

View on PubMed ↗Publisher’s paper ↗

Citation

Blankman, Jacqueline L; Cravatt, Benjamin F. (2013). Chemical probes of endocannabinoid metabolism.. Pharmacological reviews, 65(2), 849-71. https://doi.org/10.1124/pr.112.006387