Why letting go is not just a matter of willpower — and how you can support the biology of recovery
We tend to talk about heartbreak as if it were purely emotional.
You have to accept it.
Stop thinking about them.
Move on.
Give it time.
But anyone who has experienced a painful breakup, rejection or abandonment knows that it does not feel like a simple thought you can switch off.
Your body reacts too.
You may wake up with a knot in your stomach. You cannot stop thinking. You check your phone even though you know there will be no message. You lose your appetite — or suddenly crave sugar, alcohol and comfort food. You may feel restless, unsafe or almost physically ill.
That is because heartbreak is not only psychological.
It is also neurobiological.
Research into social rejection shows that some of the brain systems involved in physical pain, stress regulation, reward and social connection are also activated when we feel rejected or excluded. The endogenous opioid system — the system in which our own endorphins operate — responds directly to both social acceptance and rejection.
This gives us a completely different way of looking at heartbreak.
Not as weakness.
Not as lack of discipline.
But as a nervous system that has temporarily lost an important source of safety and regulation.
Your own internal safety system
Endorphins are usually associated with exercise or the so-called “runner’s high”, but that is only part of their role.
Our endogenous opioid system is also involved in attachment, social reward, pain regulation and feelings of connection and safety. Current research supports an important relationship between social bonding and the endogenous opioid system, although the precise mechanisms in human attachment are still being investigated.
When you feel deeply connected to another person, your nervous system gradually learns:
I am safe here.
The sound of their voice, physical contact, familiar routines, messages, shared meals and simply knowing that person is there can all become part of your biological regulation.
Then the relationship disappears.
And your nervous system has not caught up yet.
One way to understand this is as an endorphin crash: the external source of familiarity, connection and reward suddenly vanishes while the brain is still expecting it.
That may help explain why heartbreak can resemble withdrawal.
Your rational brain may understand perfectly well that the relationship has ended.
Your biology is still looking for the person.
Why rejection affects some people much more deeply than others
Not everybody responds to a breakup in the same way.
One person is devastated for several days but gradually regains equilibrium. Another may remain dysregulated for months, experiencing intense abandonment anxiety, obsessive thinking or an almost unbearable need to reconnect.
Part of that difference is shaped by our history.
Early-life stress and adversity can leave measurable epigenetic signatures in genes involved in stress regulation. One of the systems being studied is POMC — proopiomelanocortin. POMC is a precursor molecule from which several biologically active peptides are produced, including β-endorphin.
Studies in both animals and humans show that childhood adversity can be associated with altered methylation of POMC and other genes involved in the stress response.
That does not mean there is one “abandonment gene”, nor that we can look at POMC and predict someone’s attachment style.
But it does illustrate something important:
The way we respond to emotional stress is partly shaped by biology, and biology itself can be shaped by earlier experiences.
This is one of the most interesting areas where neurobiology, psychology and epigenetics meet.
When love itself activates the alarm system
There is another paradox.
For someone who has learned early in life that closeness can also mean unpredictability, rejection or pain, intimacy may activate two opposing systems at once.
Part of you wants to move closer.
Another part of your nervous system says:
Danger.
This can create the confusing push-pull pattern we often see in relationships: intense attraction, followed by anxiety, withdrawal, panic or an urge to escape as soon as genuine emotional intimacy develops.
Within the integrative epigenetic model described by Lucas Flamend in The Endorphin Recovery Plan, this is discussed in terms of disturbed endorphin regulation and what he describes as endorphinergic stress. His work combines the endogenous opioid system with the endocannabinoid system, stress biology, trauma and epigenetic regulation.
Whether we use that particular model or the broader language of attachment and stress neurobiology, the principle is useful:
Sometimes the problem is not that someone does not want connection. Their nervous system has learned to experience connection as potentially unsafe.
Anandamide: the biology of letting go
And then there is another fascinating system: the endocannabinoid system.
One of its best-known signalling molecules is anandamide, sometimes nicknamed the “bliss molecule”.
I prefer to think of it in this context as part of our biological letting-go system.
Anandamide is involved in stress regulation, emotional learning and the extinction of fear responses. One of the enzymes responsible for breaking anandamide down is called FAAH — fatty acid amide hydrolase.
This matters because experimental human research has shown that reduced FAAH activity, and therefore stronger anandamide signalling, is associated with improved extinction of learned fear and lower stress reactivity. Pharmacological FAAH inhibition has even produced a large rise in anandamide in experimental studies and improved the recall of fear-extinction learning.
Think about what happens after a painful breakup.
You see a photograph.
A song comes on.
You drive past a familiar place.
Your phone makes a sound.
And within milliseconds the old emotional programme fires.
The goal is not to erase the memory.
The brain has to learn:
This memory exists, but I am safe now.
That is essentially what fear-extinction learning does.
The memory remains.
The alarm attached to it gradually becomes weaker.
Can nutrition and phytotherapy support this process?
This is where things become especially interesting from an integrative perspective.
We cannot supplement away grief. Neither should we try.
Grief contains information and requires processing.
But we can create biological conditions in which the brain has a better chance of regulating itself.
Kaempferol and the endocannabinoid system
Kaempferol is a naturally occurring flavonoid found in foods including broccoli and endive.
In laboratory research comparing commonly occurring flavonoids, kaempferol was the most potent inhibitor of FAAH that was tested. By reducing FAAH activity in cells, it reduced the breakdown of anandamide.
That makes kaempferol particularly interesting from an integrative epigenetic perspective.
But there is an important distinction.
The laboratory evidence demonstrates FAAH inhibition in vitro. We cannot yet conclude that taking a particular dose of kaempferol automatically produces a clinically meaningful increase in brain anandamide in humans.
So I see kaempferol as a promising nutritional tool, not as a drug-like treatment for heartbreak.
Apigenin and nervous-system calm
Another interesting flavonoid is apigenin, naturally present in parsley, celery and chamomile.
Apigenin has been studied for its effects on GABAergic signalling, stress pathways, neuroinflammation and neuroplasticity. Animal studies suggest anxiolytic and antidepressant-like effects and possible involvement of GABA, monoamines and BDNF-related signalling. Human clinical evidence, however, is still limited.
Within integrative protocols it may therefore be considered as part of a broader strategy aimed at reducing excessive nervous-system arousal — rather than as a stand-alone treatment.
The goal is simple:
Your brain needs to experience calm without needing the other person to create that calm for you.
That is a major part of recovery.
Go into the forest
One of the simplest interventions is also one of my favourites:
Walk among trees.
Forest exposure — often studied as shinrin-yoku or forest bathing — has repeatedly been associated with reductions in perceived stress, anxiety and short-term cortisol levels.
Trees also release volatile organic compounds often referred to as phytoncides. These compounds are being investigated as one possible biological mechanism behind some of the effects of forest exposure, alongside movement, quiet, light, sensory input and removal from an overstimulating environment.
I would not claim that inhaling phytoncides literally “repairs your amygdala”.
The science is not that far yet.
But we do know enough to say this:
A stressed human nervous system generally functions better after time in nature than after another hour of staring at a telephone waiting for somebody to text.
And sometimes that is precisely the intervention you need.
Be careful with the quick fixes
Heartbreak creates an uncomfortable emptiness.
And the brain hates emptiness.
So it starts searching for something that will change its state quickly.
Wine.
Chocolate.
Sugar.
Fast food.
Endless scrolling.
Dating apps.
Checking your ex’s social media.
Sending “just one more” message.
Each of these can create a short-lived shift in reward, arousal or emotional pain.
But there is a problem.
If every uncomfortable feeling is immediately followed by a dopamine-producing behaviour, the brain never properly learns:
I can feel this emotion and still be safe.
Alcohol can additionally disturb sleep and emotional regulation, while highly rewarding foods and compulsive digital behaviours can keep reward-seeking loops active.
The goal after heartbreak is therefore not to eliminate every difficult feeling.
It is to stop repeatedly teaching the brain that the difficult feeling can only be survived by escaping from it.
Heartbreak needs time — but time is not the only ingredient
“You just need time” is only partly true.
Your nervous system needs new experiences during that time.
Experiences of safety without that person.
Pleasure without that person.
Calm without that person.
Connection with other people.
Movement.
Good food.
Sleep.
Nature.
New places.
New memories.
Every time your brain experiences something that used to trigger the old alarm and discovers that nothing terrible happens, another tiny piece of relearning takes place.
The prefrontal cortex gains more control.
The alarm response loses some of its power.
The craving becomes less urgent.
And eventually you notice something remarkable.
You can still remember the person.
You may even still care about them.
But your body no longer reacts as if your survival depends on getting them back.
That is what letting go really looks like.
Not forgetting.
Not becoming indifferent.
But reaching the point where the memory no longer controls your nervous system.
And perhaps that is the most useful message neurobiology can give us about heartbreak:
You do not have to force yourself to stop feeling. You need to help your brain learn that you are safe again.
Liesbeth van Duijn 