If this is true, it would be a major achievement. The drug appears to bind with a number of receptors in the brain, to include those for dopamine. It blocks the "reward centers" in the brain.
Did Scientists Accidentally Invent an Anti-addiction Drug?
All her life, Victoria Rutledge thought of herself as someone with an addictive personality. Her first addiction was alcohol. After she got sober in her early 30s, she replaced drinking with food and shopping, which she thought about constantly. She would spend $500 on organic groceries, only to have them go bad in her fridge. “I couldn’t stop from going to that extreme,” she told me. When she ran errands at Target, she would impulsively throw extra things—candles, makeup, skin-care products—into her cart.
Earlier this year, she began taking semaglutide, also known as Wegovy, after being prescribed the drug for weight loss. (Colloquially, it is often referred to as Ozempic, though that is technically just the brand name for semaglutide that is marketed for diabetes treatment.) Her food thoughts quieted down. She lost weight. But most surprisingly, she walked out of Target one day and realized her cart contained only the four things she came to buy. “I’ve never done that before,” she said. The desire to shop had slipped away. The desire to drink, extinguished once, did not rush in as a replacement either. For the first time—perhaps the first time in her whole life—all of her cravings and impulses were gone. It was like a switch had flipped in her brain.
As semaglutide has skyrocketed in popularity, patients have been sharing curious effects that go beyond just appetite suppression. They have reported losing interest in a whole range of addictive and compulsive behaviors: drinking, smoking, shopping, biting nails, picking at skin. Not everyone on the drug experiences these positive effects, to be clear, but enough that addiction researchers are paying attention. And the spate of anecdotes might really be onto something. For years now, scientists have been testing whether drugs similar to semaglutide can curb the use of alcohol, cocaine, nicotine, and opioids in lab animals—to promising results.
Semaglutide and its chemical relatives seem to work, at least in animals, against an unusually broad array of addictive drugs, says Christian Hendershot, a psychiatrist at the University of North Carolina at Chapel Hill School of Medicine. Treatments available today tend to be specific: methadone for opioids, bupropion for smoking. But semaglutide could one day be more widely useful, as this class of drug may alter the brain’s fundamental reward circuitry. The science is still far from settled, though researchers are keen to find out more. At UNC, in fact, Hendershot is now running clinical trials to see whether semaglutide can help people quit drinking alcohol and smoking. This drug that so powerfully suppresses the desire to eat could end up suppressing the desire for a whole lot more.
The history of semaglutide is one of welcome surprises. Originally developed for diabetes, semaglutide prompts the pancreas to release insulin by mimicking a hormone called GLP-1, or glucagon-like peptide 1. First-generation GLP-1 analogs—exenatide and liraglutide—have been on the market to treat diabetes for more than a decade. And almost immediately, doctors noticed that patients on these drugs also lost weight, an unintended but usually not unwelcome side effect. Semaglutide has been heralded as a potentially even more potent GLP-1 analog.
Experts now believe GLP-1 analogs affect more than just the pancreas. The exact mechanism in weight loss is still unclear, but the drugs likely work in multiple ways to suppress hunger, including but not limited to slowing food’s passage through the stomach and preventing ups and downs in blood sugar. Most intriguing, it also seems to reach and act directly on the brain.
GLP-1 analogs appear to actually bind to receptors on neurons in several parts of the brain, says Scott Kanoski, a neurobiologist at the University of Southern California. When Kanoski and his colleagues blocked these receptors in rodents, the first-generation drugs exenatide and liraglutide became less effective at reducing food intake—as if this had eliminated a key mode of action. The impulse to eat is just one kind of impulse, though. That these drugs work on the level of the brain—as well as the gut—suggests that they can suppress the urge for other things too.
In particular, GLP-1 analogs affect dopamine pathways in the brain, a.k.a the reward circuitry. This pathway evolved to help us survive; simplistically, food and sex trigger a dopamine hit in the brain. We feel good, and we do it again. In people with addiction, this process in the brain shifts as a consequence or cause of their addiction, or perhaps even both. They have, for example, fewer dopamine receptors in part of the brain’s reward pathway, so the same reward may bring less pleasure.
In lab animals, addiction researchers have amassed a body of evidence that GLP-1 analogs alter the reward pathway: mice on a version of exenatide get less of a dopamine hit from alcohol; rats on the same GLP-1 drug sought out less cocaine; same for rats and oxycodone. African vervet monkeys predisposed to drinking alcohol drank less on liraglutide and exenatide. Most of the published research has been conducted with these two first-generation GLP-1 drugs, but researchers told me to expect many studies with semaglutide, with positive results, to be published soon.