Episode 34: What Ozempic Is Actually Doing to Your Brain | GLP-1s, Food Noise and Nervous System Healing

This episode and article contain discussions around emotional eating, binge eating, body image, trauma, and weight loss medications including GLP-1s such as Ozempic and semaglutide. Please engage gently. This content is educational in nature and reflects published research and personal perspective. It is not medical advice and does not recommend for or against any medication. Please consult a qualified healthcare professional before making any medical decisions. If you are struggling with an eating disorder or severe distress around food or your body, please seek support from a qualified healthcare professional.

There's a conversation happening right now about weight loss medications. And almost everyone is either for them or against them.

But that's not the conversation I'm interested in.

What I'm curious about is what's actually happening in the brain and the nervous system when people take these medications. Because when you look at the research, what you find isn't just about appetite. It's about regulation. It's about what it feels like when a system that has been running on threat and scarcity for years finally gets a different signal.

And that's a conversation worth having.

First, a note on what this is and what it isn't

I'm not a medical doctor, a pharmacist, or a prescribing practitioner of any kind. I'm an IFS practitioner who is deeply curious about what's happening in the nervous system. Everything in this episode and this post is drawn from published research, which I'll reference throughout, and from my own reading and learning in this space.

This is not medical advice. It is not a recommendation to take or not take any medication. If you're considering any kind of medical intervention, please talk to a qualified health professional who knows your individual situation.

What I'm bringing here is a layer of this conversation that I don't think is being talked about enough. The medical side is for your doctor. The nervous system piece is what I want to explore.

What regulation actually means

Before we get into the medications, I want to talk about regulation. Because I think the way it gets described online, particularly on social media, does it a disservice.

Regulation is not about being calm all the time. It's not about being unbothered or always having it together. Regulation is simply the capacity to move through different states, whether you're activated or resting, whether things are intense or easy, without getting stuck at either extreme.

A regulated system can get stressed and then settle again. It can be pulled off centre and find its way back. It can feel something intense and return to baseline.

Dysregulation is the opposite. It's where the system gets stuck. It's a low grade state of activation that never fully turns off. Not crisis, but never fully calm either. Always slightly braced. Always scanning. Always on.

For many people, particularly those who grew up in environments that were unpredictable, chaotic, or emotionally unsafe, that low grade activation isn't a bad habit or something to breathe your way out of. It's a trained physiological response. The body learned early: don't relax, something bad might happen. And over time that becomes the baseline. That becomes normal. Because it's what kept you safe.

Most people don't know they're dysregulated if they've never experienced the alternative. Until something changes.

The brainstem: the oldest part of you

At the base of the brain sits the brainstem. It's the oldest part of us evolutionarily. It was here before we had language, before we had memory, before we had the capacity to reflect on our own experience. Its job, always, is asking one question: am I safe enough right now?

It regulates things we don't consciously control. Heart rate, breathing, gut motility, baseline muscle tension, where our attention automatically goes. And based on what it reads in the body and the environment, it either signals safety or signals threat.

Here's the critical thing. This system does not use logic. It doesn't read context. It reads patterns and it reads history. When the brainstem is activated, the prefrontal cortex, the logical, rational part of the brain, is generally not online.

Stephen Porges, a neuroscientist who developed polyvagal theory, introduced the concept of neuroception. A subconscious threat detection process that operates below the level of conscious awareness. Your nervous system is constantly reading cues in your environment and your body and deciding whether you're safe or not before you've had a single conscious thought about it.

Which means you can be sitting in a completely safe environment, objectively fine, nothing actually wrong, and your brainstem can still be running a threat response. Because it's operating off older data. Off a system that learned, back then, that calm meant stay ready.

What does that look like from the inside? Tightness in the body you can't quite explain. Attention that keeps scanning for what's wrong. An inability to fully settle. Subtle irritation without a clear cause. A sense of always being slightly behind, slightly on the edge of something.

This isn't a personality trait. This is a brainstem that learned its job very well.

The hypothalamus: your internal accountant

Sitting above the brainstem is the hypothalamus. It's doing something related but distinct. It's managing resources. Integrating signals about energy availability, blood glucose, hormones, stress, hunger, thirst, temperature, sleep. And it's constantly asking: do we have enough, or do we need to mobilize?

Like the brainstem, the hypothalamus works off pattern recognition as much as real time data. If you grew up in an environment of scarcity, whether that was emotional scarcity, physical unpredictability, chronic stress, or even food scarcity, the hypothalamus may have calibrated towards a bias of there's not enough.

A 2022 review published in Frontiers in Psychiatry looked at childhood trauma and its effects on the HPA axis, the body's central stress response system. It found that early trauma can sensitize this system, altering how it responds to stress long into adulthood.

A 2023 paper published in Psychoneuroendocrinology looked specifically at people with eating disorders and found that early traumatic experiences were consistently associated with HPA axis dysregulation, and that this dysregulation was linked to disordered eating behavior. Not as a personality flaw. As a measurable biological consequence of what the system went through.

What does that hypothalamic bias feel like in the body? A chronic preoccupation with food that isn't really about physical hunger. Difficulty feeling truly satisfied after eating. A sense of urgency without a clear object. A restlessness. A feeling of always being slightly depleted.

And here's where it gets interesting. The brainstem and the hypothalamus are in constant communication. The brainstem's threat signal feeds directly into the hypothalamus's resource assessment. So when the brainstem is activated, the hypothalamus reads: conditions are unstable, keep looking, don't fully settle, find resources.

You end up with a system where both the safety signal and the resource signal are biased towards alert. Not because anything is currently wrong. Because the system was shaped in a context where things were.

The reward system and food noise

The brain's reward circuitry is driven primarily by dopamine and centered in a region called the nucleus accumbens. It's designed to motivate us towards things that keep us alive. Food, connection, safety, novelty. It creates urgency and a pull towards things that matter.

But in a chronically activated nervous system, this system gets recruited for something else entirely. Regulation.

When your baseline state is dysregulation, when you're carrying that low grade brainstem activation and that hypothalamic seeking signal, your brain is going to look for fast ways to change the state. Fast ways to find safety and resources. Things that offer quick relief, a quick shift in how the body feels.

Food is the most efficient option available. Not because of a character flaw or lack of willpower. Because your nervous system learned, very accurately, that this works. Eating, particularly high reward food, creates a rapid dopamine response that briefly interrupts the activation. It changes the way you feel.

So does scrolling. So does the mental loop of planning and researching and obsessing. So does anything that creates a hit of novelty or sensation.

These aren't bad habits. They are a dysregulated nervous system doing precisely what it was wired to do. Finding a way to regulate itself using the tools available.

What we call food noise, that constant hum of thinking about food, wanting something, searching, it's not really about food. It's the sound of a system looking for relief. Looking for regulation.

And a 2021 systematic review published in the journal Nutrients found that the same class of medications we're about to discuss appeared to modulate reward circuitry in ways that reduced seeking behavior across multiple domains, not just food. People reported drinking less alcohol, smoking less, feeling less of that compulsive pull towards relief across the board. Because these aren't separate problems with separate solutions. They're expressions of the same underlying system.

So what are these medications actually doing?

When people take GLP-1 medications like Ozempic or Wegovy, many report something unexpected. Not just that they eat less, but that the food noise quietens or stops entirely. The mental searching, the urgency, the constant low level pull. It quiets.

For many people, especially those who've experienced that noise their whole lives and just assumed that's who they were, that quiet is enormous.

The research points to three main mechanisms.

The first is blood sugar stabilization. These medications slow gastric emptying, creating more consistent satiety signals and reducing glucose volatility. Blood sugar dips, even small ones, are read by the nervous system as a low level stress signal. When that smooths out, the hypothalamus receives more consistent data that says we are resourced, we are okay. And the seeking signals begin to quiet.

The second is that these medications act directly on receptors in the brainstem and hypothalamus. Research published in the Journal of Neuroscience in 2024 mapped specific populations of neurons in the brainstem that carry receptors for this class of drug and found that these neurons send projections all the way up into the hypothalamus and the limbic system, the emotional brain. When the medication activates these receptors, it's changing the input data that the brainstem and hypothalamus are receiving. Less urgency in the signal. Less of the mobilize now.

The third, and the one drawing the most attention in recent research, is that these medications appear to change activity in the reward system. Specifically they reduce what researchers call reward salience, the degree to which something feels urgent and necessary. A 2025 paper found that semaglutide reduced appetite while actually improving the quality of dopamine reward signaling. The compulsive restless seeking quietens. But the capacity for genuine satisfaction remains. And in some cases deepens.

Food stops feeling like it needs to happen right now. The urgency quietens. The searching quietens.

And in that quietness, something remarkable can happen. People start to notice things they haven't noticed before. The quality of light in the afternoon. The warmth of the sun. A feeling in the chest that might be described, carefully, as peace.

Some say: for the first time I feel like I'm starting to see the world.

This isn't a side effect. This is what becomes available when the threat in the brainstem quietens. When the brainstem finally gets consistent enough safety data to shift towards what polyvagal theory calls a ventral vagal state. A state of genuine safety, openness, and connection.

These states are not created by the medication. They're uncovered. They're what's there when the noise drops low enough.

Which means something important. The capacity you didn't think you had was always there.

What this means for healing

Understanding all of this at a biological level changes the way we frame emotional eating entirely. Because what looks like compulsion, or lack of discipline, or food obsession, is actually a nervous system doing the job it was trained to do in the context it was trained in.

And you can't think your way out of a brainstem response. You can't journal your way to a regulated hypothalamus. What these systems respond to is evidence. Consistent, repeated, embodied evidence that things are different now.

That looks like physiological stability. Stable blood sugar, sleep, hydration. These aren't boring basics. They are literally changing the data your brainstem is working with. Every stable meal is a signal. Every consistent sleep is a signal.

It looks like reducing internal conflict and building a relationship with your experience that doesn't require constant management and suppression. In IFS we call this working with polarizations, the parts of you that are in conflict with each other, pulling in opposite directions. You can't fix a polarization until both parts feel seen and heard.

It looks like predictable safety. In your environment, your relationships, your own nervous system's rhythms. A slow accumulation of evidence that when I relax, nothing bad happens.

For some people, these medications create a window where this work becomes possible. When a protector part quietens, even temporarily, the parts underneath have room to come forward. Healing becomes accessible in a way it wasn't when the system was working so hard just to survive the day.

But the medication doesn't do the healing. You still need to heal what's underneath. What it can do is create the conditions where healing has more space to happen.

The question I keep coming back to

Why do some people feel more like themselves on these medications? What does it mean when someone says they feel regulated for the first time? And what does that reveal about what was happening before?

Those are the questions I care about. And they're the ones I'll keep pulling on. In a future episode I'm going to sit down with an expert at the forefront of the conversation around metabolic health, peptides, and what these medications are actually doing at a nervous system level. We're going to take everything covered here much deeper.

If this episode resonated, stay tuned. And if someone in your world needs to hear that what they've experienced is real, that there's a biological explanation for it, please share it.

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References

1. Childhood trauma and the HPA axis Murphy, F., Nasa, A., Cullinane, D., Raajakesary, K., Gazzaz, A., Sooknarine, V., Haines, M., Roman, E., Kelly, L., O'Neill, A., Cannon, M., & Roddy, D.W. (2022). Childhood Trauma, the HPA Axis and Psychiatric Illnesses: A Targeted Literature Synthesis. Frontiers in Psychiatry, 13, 748372. https://doi.org/10.3389/fpsyt.2022.748372

2. Early trauma, HPA axis dysregulation, and eating disorders Cascino, G., et al. (2024). Early traumatic experiences and the hypothalamus-pituitary-adrenal axis in people with eating disorders: A narrative review. Psychoneuroendocrinology, 159, 106665. https://doi.org/10.1016/j.psyneuen.2023.106665

3. GLP-1 and reward system related disorders (food, alcohol, drugs) Eren-Yazicioglu, C.Y., Yigit, A., Dogruoz, R.E., & Yapici-Eser, H. (2021). Can GLP-1 Be a Target for Reward System Related Disorders? A Qualitative Synthesis and Systematic Review Analysis of Studies on Palatable Food, Drugs of Abuse, and Alcohol. Frontiers in Behavioral Neuroscience, 14, 614884. https://doi.org/10.3389/fnbeh.2020.614884

4. Hindbrain GLP-1 neurons and projections to the hypothalamus (Journal of Neuroscience 2024) Randolph, A.B., Zheng, H., & Rinaman, L. (2024). Populations of hindbrain glucagon-like peptide 1 (GLP1) neurons that innervate the hypothalamic PVH, thalamic PVT, or limbic forebrain BST have axon collaterals that reach all central regions innervated by GLP1 neurons. Journal of Neuroscience, 44(31), e2063232024. https://doi.org/10.1523/JNEUROSCI.2063-23.2024

5. Semaglutide, appetite reduction and dopamine reward signaling Kooij, K.L., Koster, D.IJ., Eeltink, E., Luijendijk, M., Drost, L., Ducrocq, F., & Adan, R.A.H. (2024). GLP-1 receptor agonist semaglutide reduces appetite while increasing dopamine reward signaling. Neuroscience Applied, 3, 103925. https://doi.org/10.1016/j.nsa.2023.103925

6. Polyvagal theory and neuroception Porges, S.W. (2004). Neuroception: A subconscious system for detecting threats and safety. Zero to Three, 24(5), 19–24. (Foundational reference for polyvagal theory)

A note worth including on your blog post: the Psychoneuroendocrinology paper was published online in November 2023 and appears in the January 2024 volume, so it may be listed as either 2023 or 2024 depending on where you look. Both are correct.