GLP-1s Are Quietly Killing Your Cravings (and Maybe Your Bad Habits Too)
New brain-imaging studies reveal these meds may silence the impulse engine driving addiction, compulsive behaviours, and billion-dollar snack aisles
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My first existential crisis arrived at age 16, courtesy of Richard Dawkins and his annoyingly persuasive ‘The Selfish Gene’ (a delightfully cheery read for teenagers, highly recommend).
The second landed right on schedule at 27, thanks to neuroendocrinologist Robert Sapolsky’s ‘Behave’, a book that convincingly argues our behaviours are driven less by conscious choice and more by powerful, invisible hormones.
Sapolsky made me seriously reconsider everything I thought I knew about why we do what we do. If our choices are really just biochemistry in disguise, what does that mean for how we treat obesity, addiction, or compulsive behaviours?
Maybe it’s time we finally admit who's really running the show. Those powerful chemicals quietly coursing through our brains.
And that's where we're headed today.
📊 Inside the Numbers
What happens when you can actually watch sugar cravings disappear from someone's brain? — You've probably heard people talking about 'food noise’. It’s that persistent, nagging voice in your head that keeps whispering about donuts, pizza, or cookies.
For many struggling with obesity, this chronic craving for sugar and fat feels like a voice you just can't mute.
But when people begin taking GLP-1 medications, it's as though someone finally found the volume knob and dialled it down to zero. The experience is something like an instantaneous liberation, so surreal and dramatic it almost feels like magic.
Recently, a good friend described starting tirzepatide this way:
"Bro, my food noise just vanished. Gone. Poof. I finally had the freedom to think about other things. And my shopping basket changed overnight. I actually wanted leafy greens and sweet potato. Sweet potato! Do you know how crazy that is?”
Stories like my friend's are piling up everywhere. So what's actually happening inside the brain when food noise just... stops?
When the brain says no
We've known for a while that GLP-1 meds like semaglutide dial down cravings, but now we've got visual proof of it actually happening in the brain.
A groundbreaking randomized controlled trial just published in Nature Medicine, used functional MRI (fMRI) scans to watch people's brains in real-time as they looked at images of high calorie, high sugar foods (think pizza, cakes, burgers etc) while taking tirzepatide, liraglutide, or a placebo.
After just three weeks on tirzepatide, the brain regions that light up when we see junk food went quiet. The areas responsible for cravings and reward anticipation (like the cingulate gyrus and medial frontal gyrus) showed roughly 170 % to 220 % less activation than they did on placebo, meaning these brain regions actually went into suppression.
You’d think a drug like this would just crush hunger everywhere, like a sledgehammer smashing through a wall. Nope. Tirzepatide works more like an elite sniper perched on a rooftop, laser focused and zeroing in on your strongest cravings for high calorie, high sugary crap and picking them off with precision.
Amazingly, it leaves your appetite for fresh salads, crisp veggies, and sweet raspberries untouched.
The $1.2 Billion Question
Now, let’s zoom out for a second. What happens if millions of us suddenly lose that intense urge for soda, chips, or those wonderful chocolate chip cookies from subway (my fave)?
Agricultural economist Brian E. Roe calculated that even moderate levels of adoption of GLP-1s, say 10% among overweight people and 20% among those with obesity, would lead to a 3% drop in total calorie demand in the U.S.
That translates to around 20 billion fewer calories eaten daily and $1.2 billion less spent each week on food and drinks.
In other words, companies like Coca-Cola, Kellogg's, and Nestlé, who’ve built sprawling empires by tapping directly into the very cravings we've just seen silenced on MRI, may soon face an existential threat.
Some innovative companies, however, have already started adapting.
Smoothie King sensed the winds shifting first, cleverly rolling out high-protein, GLP-1-friendly shakes to capture the health-aware consumer.
Expect other fast-moving brands to dive headfirst into a wave of products customized specifically for people freed from the constant grip of food cravings.
The rest will need to pivot quickly or risk fading into oblivion.
GLP-1s as Impulse Dampeners
But tirzepatide might be doing something even more profound than silencing food noise. The same study suggests it's actually rewiring impulse control in the brain itself.
The researchers measured impulsiveness using the Barratt Impulsiveness Scale, a validated psychological tool that captures everyday impulsive tendencies like “acting without thinking” or “struggling to resist urges.”
After 3-6 weeks of tirzepatide treatment, participants reported feeling significantly less impulsive than those who received the placebo.
They reported feeling calmer, more in control, and far less prone to snap decisions or irresistible urges.
This is important when you consider that impulsivity is the engine behind pretty much every self-destructive habit out there. Whether you're talking binge-drinking, gambling, chain-smoking or falling into the black hole of substance abuse.
If GLP-1 meds can dial down the noisy circuits in our brains screaming 'just do it!', we might be staring down the barrel of an entirely new way of treating addiction and it’s devastating consequences.
Just imagine a world (to borrow from John Lennon) with fewer overdose headlines, calmer Friday nights in emergency rooms, shrinking gambling debts, maybe even drops in domestic violence and incarceration rates.
Researchers are taking this seriously.
Major clinical trials already underway are testing whether GLP-1 meds might quiet the destructive impulses behind addiction itself. If they're right, we're looking at something much bigger (and far more important) than just weight loss.
Compound giveth, compound taketh — This data, compiled from a combination of IQVIA, Trilliant Health, Komodo Health, Novo Nordisk, and Eli Lilly reports, triangulates both branded and compounded GLP-1 prescription volumes.
While compounded GLP-1 prescriptions surged dramatically, peaking at an incredible 25% of total GLP-1 prescriptions by late 2024, the trend sharply reversed afterward, plummeting to just 2-3% by mid-2025.
I think this rapid decline after 2024 signals that most telehealth providers and compounding pharmacies have read the regulatory tea leaves and stepped back.
The risk of tighter enforcement clearly outweighed the benefits, except, notably, for Hims. As I discussed last week, Hims has continued to aggressively drive compounded GLP-1 prescriptions, seemingly unbothered by looming regulatory crackdowns.
Their ongoing bet on compounding positions them in direct competition—and perhaps conflict—with Novo Nordisk, setting up a tense showdown over how far compounders can push their advantage before lawsuits start being thrown about.
🔎 Policy Watch
GLP-1s Become First Line — Just recently, the American College of Cardiology (ACC) dropped some seriously big news that no one seems to be talking about.
They've now stated that GLP-1 medications (like Wegovy and Zepbound) should be the go-to, first-line treatment for obesity and weight management. This is a big shift from the tired old "try eating better and hitting the gym first" advice we've been hearing basically forever, and the ACC is flat-out calling that approach outdated.
If you’ve subscribed to my newsletter for any length of time, this makes complete sense.
Relying solely on lifestyle changes hasn't exactly delivered impressive results when it comes to protecting our hearts. Now we've got enormous real-world trials showing that semaglutide cuts major heart risks like heart attacks, strokes, and even cardiovascular-related deaths by around 20% in overweight or obese patients, even if they don't experience significant weight loss.
That’s seriously impressive.
However, the ACC’s new position is going to throw a serious wrench in how health insurers currently do business.
Right now, most insurers drag patients through exhausting hoops called "prior authorizations." Patients have to show proof they've already struggled through lifestyle coaching programs or failed cheaper, older meds before insurers finally cave and approve GLP-1s for obesity.
According to WTW’s major 2024 healthcare survey—covering 417 large U.S. employers representing about 6 million employees—not only do many insurers still cling to these outdated hurdles, but 55% of them are actually planning to require even more participation in lifestyle modification programs before approving GLP-1 treatments within the next two years.
So insurers are doubling down on exactly the approach the ACC just explicitly rejected as outdated and ineffective.
Caught in the middle are millions of patients who see life-changing treatments dangling just out of reach, stuck playing bureaucratic games that seem completely bonkers and morally indefensible.
Surely, something has to give.
If insurers continue to dig their heels in against overwhelming medical consensus and patient demand, people are just going to go to the grey market, get these meds without supervision and risk their health and safety on an exploding shadow economy.
Loved this. Makes me wonder if the next frontier isn’t just GLP-1 expansion, but a broader appetite to tackle adjacent high-cost conditions like SUD. MAT has saved lives, but the system still fails too many — feels like we’re overdue for a step change in addiction care.
Are you aware if there have been any similar brain scan studies on retatrutide as the tirzeptitide cited? Fascinating!