What if your body could produce its own cannabinoids? It can. Anandamide is a naturally occurring chemical that interacts with the same cannabinoid receptors activated by THC. Discovered in pig brain tissue in 1992, it helped scientists understand why the human body has an endocannabinoid system in the first place. Its name comes from the Sanskrit word for bliss, earning it the popular nickname "the bliss molecule." But the science behind anandamide goes much further than happiness. It involves how the body regulates pain, processes fear, responds to exercise and controls its own cannabinoid signaling.
The 1992 Discovery: Finding the Body's Own Cannabinoid
Anandamide, chemical structure — NEUROtiker, public domain, via Wikimedia Commons
The discovery of anandamide began with a question scientists had been asking since identifying the first cannabinoid receptor.
If the human brain has dedicated receptors that respond to cannabinoids, what naturally occurring chemical activates them?
In 1990, researchers had successfully cloned CB1, establishing the molecular identity of the receptor responsible for many of cannabis's effects in the nervous system.
Scientists now had evidence of a specific receptor, but they still needed to find its natural chemical messenger.
A research team at the Hebrew University of Jerusalem, led by William Devane, Lumír Hanuš, Raphael Mechoulam and colleagues, set out to find it.
They screened extracts of brain tissue for a substance capable of binding to the cannabinoid receptor.
Their search led them to pig brain tissue.
In 1992, the researchers isolated and identified a previously unknown endogenous cannabinoid. They named it anandamide, also known by its chemical name N-arachidonoylethanolamine and abbreviated AEA.
The discovery was published in Science under the title "Isolation and Structure of a Brain Constituent That Binds to the Cannabinoid Receptor."
It established something fundamental: the body produces its own cannabinoid compounds.
Cannabis was not introducing the body to an entirely foreign biological system. Its compounds were interacting with receptors that already had naturally occurring chemical partners.
Why Is It Called the Bliss Molecule?
The name anandamide has two parts.
The first comes from the Sanskrit word ananda, meaning bliss, joy or delight.
The second, amide, refers to the chemical class of the molecule.
The name was introduced in the original 1992 research paper.
This is where the familiar nickname "the bliss molecule" comes from. It is a popular media description derived from the molecule's name, not an experimentally established description of its effects.
There is also an interesting detail behind the naming.
Mechoulam later recalled that William Devane was learning Sanskrit at the time and suggested the word "ananda" for the new molecule's name.
Although anandamide is commonly described as the bliss molecule, the popular nickname appears to be a later media description, and its original use is difficult to trace.
More importantly, anandamide does not simply make someone happy.
It participates in a much broader biological signaling network involving the nervous system, pain, emotional regulation and other functions.
How Your Body Makes Anandamide
Unlike many neurotransmitters, anandamide is not manufactured in advance and stored in large quantities for later release.
The body produces it on demand.
Anandamide is synthesized from a membrane lipid called N-arachidonoyl phosphatidylethanolamine (NAPE).
One of the main known pathways involves an enzyme called:
NAPE-PLD.
This enzyme helps convert NAPE into anandamide.
Research published by Okamoto and colleagues in 2004 helped establish the role of NAPE-PLD in this process.
However, it is important to understand that this is the main known route, not the only possible pathway for anandamide production.
The on-demand nature of its production is one of the most important features of the molecule.
Rather than maintaining a large stored supply, the body creates anandamide when particular signaling conditions call for it.
It acts locally, interacts with its receptors and is quickly broken down.
FAAH: The Enzyme That Breaks Anandamide Down
Producing anandamide is only half of the process.
The body also needs a way to remove it.
That job belongs largely to an enzyme called fatty acid amide hydrolase, or FAAH.
FAAH breaks anandamide into two components:
Arachidonic acid
Ethanolamine
The enzyme was cloned and characterized by Benjamin Cravatt and colleagues in 1996, in research published in Nature.
The discovery helped explain how the body controls the duration of endocannabinoid signaling.
Anandamide is not intended to remain active indefinitely.
Anandamide is rapidly metabolized, primarily by FAAH, helping regulate how long its signaling remains active. Its lifetime depends on the biological environment in which it is produced.
What Happens When FAAH Is Missing?
Experiments involving mice without functional FAAH revealed just how important this enzyme is.
These animals had approximately 15 times more anandamide in their brains than normal mice.
The finding demonstrated how strongly FAAH controls the body's natural anandamide levels.
It also attracted attention from pharmaceutical researchers.
If scientists could safely reduce FAAH activity, they might be able to increase naturally produced anandamide without directly administering cannabis or THC.
That idea would eventually become the foundation of an entire drug-development program.
Anandamide vs. THC: The Difference Is More Complicated Than Most People Think
One of the most common explanations of anandamide describes it as a weak version of THC.
That comparison misses an important scientific detail.
Both anandamide and THC are partial agonists at CB1 receptors.
A partial agonist activates a receptor but does not produce the same maximum response as a full agonist.
Anandamide is also relatively weak at CB2.
So what makes THC behave differently?
One major difference is pharmacokinetics, the way each substance is absorbed, distributed, metabolized and eliminated. They also differ in receptor interactions and metabolic stability.
Anandamide: Small, Local and Short-Lived
The body releases anandamide in tiny, localized pulses.
It acts near where it is produced and is rapidly broken down by FAAH.
Its biological effects are therefore tightly regulated in both location and duration.
THC: Longer-Lasting Exposure
Consumed THC behaves differently.
It can expose cannabinoid receptors throughout the body for much longer periods.
THC is lipophilic, meaning it readily distributes into fatty tissues. The liver also metabolizes THC into 11-hydroxy-THC, an active metabolite that is particularly relevant following oral consumption. THC and its metabolites can remain detectable after the intoxicating effects have subsided, so detection windows should not be confused with the duration of intoxication.
The important distinction is not that THC is a full agonist while anandamide is a weak copy.
They both act as partial agonists at CB1.
The difference is how the body produces, distributes, metabolizes and eliminates them.
Anandamide is a tightly controlled local signal. Consumed THC creates a much broader and more sustained exposure.
Anandamide and the Runner's High
One of the most interesting areas of anandamide research involves exercise.
For years, scientists have investigated why prolonged physical activity can produce a feeling of reduced pain, improved mood and well-being.
The familiar term is:
The runner's high.
The traditional explanation often focuses on endorphins, the body's naturally produced opioid-like signaling chemicals.
But research has identified another possible contributor: endocannabinoids.
Exercise Raises Anandamide in Humans
In 2003, researchers led by Sparling and colleagues published findings in Neuroreport showing that exercise increased circulating endocannabinoid levels.
Subsequent research continued investigating the relationship.
Studies have found that endurance exercise can increase blood anandamide in humans.
A 2022 systematic review and meta-analysis found that acute exercise generally increased circulating endocannabinoids, including anandamide. The analysis included both human and animal studies, and researchers noted substantial variation depending on exercise intensity, fitness, measurement timing and other factors.
Research by Raichlen and colleagues in 2012 found that plasma anandamide increased following endurance running in humans and dogs, but not ferrets. Levels of 2-AG did not significantly increase in any of the three groups.
This suggests that exercise-related endocannabinoid responses may differ across species.
What Happens in Mice?
The evidence becomes particularly interesting when looking at animal experiments.
In 2015, researchers led by Johannes Fuss and colleagues published a study in Proceedings of the National Academy of Sciences examining the role of cannabinoid receptors in exercise-related behavior.
Their experiments showed that cannabinoid receptors were necessary for the reductions in anxiety and pain sensitivity observed after running in mice.
This provided strong evidence that endocannabinoid signaling contributes to some of the behavioral effects associated with exercise.
However, there is an important limitation.
Scientists cannot directly measure subjective euphoria in mice.
Human studies provide evidence that exercise can increase circulating endocannabinoids, particularly anandamide, although responses vary depending on exercise conditions and study design, and the causal role of anandamide in producing the human runner's high has not been established.
The evidence supports three conclusions:
Exercise raises circulating anandamide in humans.
Cannabinoid signaling contributes to exercise-related reductions in anxiety and pain sensitivity in mice.
Anandamide's direct causal role in human exercise-related euphoria remains unproven.
The endocannabinoid system is a leading candidate in the runner's high explanation, but it has not been established as the only explanation.
The endorphin theory has not been disproven.
Chocolate Contains Anandamide. But Does It Actually Make You Happier?
Few stories about anandamide have traveled further than the connection between chocolate and the bliss molecule.
The story began in 1996, when researchers Daniele di Tomaso, Massimiliano Beltramo and Daniele Piomelli published a study in Nature examining compounds found in chocolate.
They reported that chocolate contains anandamide itself.
They also identified two related fatty acid compounds:
N-oleoylethanolamine (OEA)
N-linoleoylethanolamine (LEA)
These compounds were interesting because laboratory research demonstrated that they could slow the breakdown of anandamide.
The finding created an appealing possibility: could eating chocolate increase the body's anandamide activity and produce a cannabis-like feeling?
The 1998 Exchange
In December 1998, a separate group of researchers led by Vincenzo Di Marzo published a follow-up correspondence in Nature, questioning whether the quantities of endocannabinoids found in chocolate were sufficient to produce meaningful cannabinoid effects. Their conclusion was that the amounts were too low to produce cannabis-like effects in mammals. In a separate response published in the same issue, original researchers Massimiliano Beltramo and Daniele Piomelli explained that two related compounds found in chocolate could inhibit anandamide degradation in laboratory experiments. This helped explain the original scientific speculation, but did not establish that eating chocolate produces a meaningful cannabinoid effect in humans.
The popular claim that chocolate lifts your mood through anandamide is therefore misleading.
The original discovery was real. Chocolate contains anandamide and related compounds.
But the follow-up research showed that the quantities are insufficient to produce cannabis-like effects.
It is an important example of how an interesting laboratory discovery can become exaggerated when separated from the research that followed it.
The FAAH Gene: Why Some People Naturally Have Higher Anandamide
Anandamide levels are not identical in everyone.
Genetic differences can influence how efficiently the body breaks down its own endocannabinoids.
One of the most studied variations involves the FAAH gene.
It is called:
C385A, or rs324420.
This genetic variant changes the behavior of the FAAH protein, making it degrade more quickly.
Because FAAH is responsible for breaking down anandamide, carriers of the variant can have reduced FAAH activity and higher anandamide levels.
The 2015 Study
In 2015, researchers led by Iva Dincheva and colleagues published a study in Nature Communications examining this genetic variation.
The researchers studied both human carriers and specially developed knock-in mice carrying the corresponding human variant.
The researchers found that human carriers of the variant showed enhanced fear-extinction learning and altered communication between the frontal cortex and amygdala. The corresponding knock-in mice also showed enhanced fear extinction and reduced anxiety-like behaviors.
Approximately 38% of people of European descent carry at least one copy of this variant.
That population qualifier matters. The figure should not be presented as a universal percentage for all populations.
The Other Side of the Research
The history of this variant is not entirely straightforward.
Its first reported association appeared in 2002, when researchers led by Sipe and colleagues published findings linking the FAAH C385A variant with problem drug use.
The original association was particularly reported among individuals homozygous for the variant. It was an association, not proof that the genetic change causes addiction.
Later research investigating the relationship between FAAH genetics and addiction has produced mixed findings.
This is why describing it as a "bliss gene" would be misleading.
The variant influences FAAH activity and anandamide regulation, but its relationship with behavior is more complicated than a simple genetic explanation for happiness or addiction.
The Drug Industry Tried to Harness Anandamide
Once scientists understood that FAAH breaks down anandamide, pharmaceutical researchers began investigating whether blocking the enzyme could produce therapeutic benefits.
The idea was relatively straightforward.
Instead of introducing THC or another cannabinoid into the body, researchers could potentially allow the body to maintain higher levels of its own anandamide.
This became a major target for drug development.
One of the most closely studied compounds was Pfizer's PF-04457845.
2012: The Osteoarthritis Trial
PF-04457845 successfully increased fatty acid amides in humans.
However, the drug failed to demonstrate meaningful benefits for osteoarthritis pain.
The results were published by Huggins and colleagues in Pain in 2012.
This was an important setback.
The ability to increase anandamide and related fatty acid compounds did not automatically translate into effective pain treatment.
2016: The French Clinical Trial Tragedy
Another FAAH inhibitor program produced a much more serious event.
In January 2016, a volunteer died during a clinical trial in France involving Bial's BIA 10-2474.
The incident raised major questions about the safety of experimental FAAH inhibitors.
However, later research provided an important distinction.
In 2017, researchers discovered that BIA 10-2474 interacted with several enzymes beyond FAAH, raising concerns about off-target activity. However, the precise cause of the neurological injuries and death remains unknown. The findings highlighted the importance of drug selectivity, but did not establish that off-target activity was definitively responsible for the tragedy.
This distinction matters.
The incident does not establish that selective FAAH inhibition itself causes this type of toxicity. Instead, it highlights the importance of evaluating each experimental compound's selectivity, off-target interactions and safety before human testing.
2019: A Different Result for Cannabis Withdrawal
PF-04457845 was subsequently investigated in a separate clinical trial led by researchers at Yale University and funded by the National Institute on Drug Abuse (NIDA). This time, researchers wanted to determine whether increasing anandamide could help people experiencing cannabis withdrawal.
In 2019, a study led by D'Souza and colleagues, published in The Lancet Psychiatry, found that FAAH inhibition helped reduce cannabis withdrawal symptoms.
This was a different clinical application from the earlier osteoarthritis trial.
The results suggested that manipulating the body's own endocannabinoid signaling might have therapeutic potential in certain circumstances.
It was an encouraging result, but the trial was small, conducted at one site and limited to men over a four-week treatment period. Larger studies would be needed to establish the treatment's effectiveness and safety across broader populations.
The Research Continues
Another compound, Janssen's JNJ-42165279, has also been investigated in clinical trials.
JNJ-42165279 was subsequently investigated in two additional Phase 2 studies. A Phase 2 autism study published online in October 2024 failed to meet any of its three primary endpoints, although several secondary measures showed small-to-moderate changes favoring treatment. A separate Phase 2a study involving 153 adults with major depressive disorder and anxious distress, published in 2026, failed to demonstrate significant improvement over placebo on its primary or key secondary efficacy endpoints.
Both studies were supported by Johnson & Johnson's Janssen pharmaceutical division. Their published disclosures also identified substantial company employment and stockholding among the authors.
As of November 2026, no FAAH inhibitor has received regulatory approval for use as a medicine.
The research remains an important part of understanding how the endocannabinoid system could potentially be targeted through the body's own chemical signaling pathways.
The Body's Own Cannabinoid Is More Complicated Than Its Nickname
Anandamide began as a scientific discovery in 1992.
Researchers were searching for the body's natural chemical partner to the cannabinoid receptor. What they found was a molecule that helped explain how the endocannabinoid system regulates communication throughout the body.
Its name came from the Sanskrit word for bliss, but its role extends far beyond happiness.
Anandamide is produced on demand, acts locally and is rapidly broken down by FAAH. It participates in cannabinoid signaling, interacts with CB1 and also activates TRPV1, a receptor involved in sensing heat and capsaicin.
It rises during exercise, participates in fear-extinction processes and has become a major subject of genetic and pharmaceutical research.
The chocolate story showed how quickly an interesting discovery can become exaggerated. The FAAH drug trials showed that manipulating the system is considerably more complicated than simply increasing anandamide.
And the runner's high research continues to raise questions about the relationship between exercise, mood and the body's own cannabinoids.
Perhaps the most important takeaway is that cannabis does not have a monopoly on cannabinoids.
Your body makes its own. And anandamide is one of the reasons scientists now understand that the endocannabinoid system is a fundamental part of human biology.
Read next
Sources
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