How GLP-1s Rewire Taste
GLP-1 drugs may fundamentally alter taste and food reward itself. From chocolate milk fMRI studies to cottage cheese obsession, let’s dive into the succulent science.
I spent a month obsessed with cottage cheese.
I ate ~36 pounds of the stuff over the course of April.
But I should back up.
I recently released an article about my personal experience taking the new GLP-1 receptor agonist, retatrutide.
I wasn’t trying to lose weight. But I did want to explore what happened under my metabolic hood, so to speak.
But there was one peculiar effect I didn’t spend much time discussing, until now: my taste changed.
It was one of the strangest effects—subtle in some ways, impossible to ignore in others.
And when I started digging into the literature, I realized there was definitely something there.
It’s well documented that GLP-1 drugs can alter taste preferences, far beyond simply reducing overall food intake. In fact, GLP-1 is directly involved in taste processing on the tongue itself. Some taste buds even produce GLP-1!
Did you know that? I didn’t.
So, today, I want to unpack:
What might be going on
What we still don’t know
What this could mean for the future of the food industry
And why understanding these mechanisms may help explain your own cravings, food preferences, and relationship with food.
Taste Starts (But Doesn’t End) on the Tongue
We have a wide array of taste buds responsible for detecting the five basic tastes: sweet, sour, salty, bitter, and umami.
The balance of those signals—how they’re encoded on the tongue and processed by the brain—ultimately determines our subjective experience of flavor.
And when you stop to think about it, given the enormous variation in human biology, especially in the brain, it’s entirely possible that my experience of a food is fundamentally different from yours.
It’s like the classic thought experiment: is my red the same as your red?
Well, is my cottage cheese the same as your cottage cheese?
Maybe my internal experience of an apple is more like your internal experience of a pear?
But let’s not get too side-tracked by philosophy.
Back to the tongue.
Some taste buds, including those involved in sweet perception, actually use GLP-1 as part of their signaling pathway to the brain.
Sugar molecules bind to receptors on the taste bud, triggering a signaling cascade, and one of the messengers involved is GLP-1. That signal then activates nearby nerves, sending information to the brain.
To be clear, this doesn’t mean GLP-1 itself tastes sweet. It’s part of the communication system.
And in the real world, many people taking GLP-1 drugs report a reduced desire for sweet and ultra-processed foods.
If you go internet sleuthing on community forums, examples abound:
“I used to demolish milk chocolate, but now I only want dark chocolate.”
“Fast food just tastes weirdly intense to me now.”
“I stopped craving my favorite candy, Skittles. But fruit suddenly tastes amazing.”
“I used to peck at Lay’s, and now sliced cucumbers genuinely sound better than chips.”
Exactly what’s going on, especially the variability among individual changes, remains unclear.
What we do know is that people with obesity often appear to be relatively desensitized to sweetness.
At a population level, researchers believe persons with obesity register sweet less intensely, driving the desire for stronger and stronger sweet stimuli. The subtle sweetness of wild blueberries may no longer feel rewarding, while something like a hot fudge sundae still delivers the desired impact.
The “sweet floor” has been recalibrated upward.
What once felt intensely rewarding now barely registers, pushing the brain toward stronger and more engineered stimuli.
But that’s only part of the story.
In the rest of this letter for StayCurious Metabolism Premium members, we’ll dive into:
The brain’s reward circuitry
Other organs that may influence food preferences
The unknowns and open questions
What all of this could mean for the food industry.
Like chocolate milk after starting a GLP-1 (as you will see), this letter is going to hit a little differently from our usual programming.
But I suppose that’s the nature of what we do here: we stay curious and follow the questions that genuinely pique our interest, as this one did mine.
