Your brain expects the signal. It has been processing it since birth. But during the first weeks on GLP-1, something changes.
The signal doesn’t change. The signal is still exactly what it has always been. What changes is the volume. The brainstem receives a fullness message stronger than anything it has processed before.
This is why nausea happens. And why it stops.
Motion sickness works the same way. Your brain learns what “normal” movement feels like. Then you board a boat, and the signal becomes something it has never experienced. Nausea follows. But after a few days, the brain recalibrates. The signal doesn’t change—your brain’s relationship to it does.
GLP-1 follows the same neurology. The brainstem calibrates. The nausea that felt overwhelming in week one is barely noticeable by week three. By week four, it’s often gone entirely.
The signal did not change. The brain’s relationship to it did.