(The Atlantic) – The drugs work as intended: as powerful modulators of appetite. But at the same time that they have become massive successes, the original science that underpinned their development has fallen apart. The fact that they worked was “serendipity,” Randy Seeley, an obesity researcher at the University of Michigan, told me. (Seeley has also consulted for and received research funding from companies that make GLP-1 drugs.)

Now scientists are beginning to understand why. In recent years, studies have shown that GLP-1 from the gut breaks down quickly and has little effect on our appetites. But the hormone and its receptors are naturally present in many parts of the brain too. These brain receptors are likely the reason the GLP-1 drugs can curb the desire to eat—but also, anecdotally, curb other desires as well. The weight-loss drugs are ultimately drugs for the brain. (Read More)