Popular weight-loss drugs show promise as addiction treatments

Encouraged by anecdotal evidence, researchers are launching clinical trials to see whether GLP-1 agonists, a popular new class of weight-loss drugs, can also help people beat addictions to drugs and alcohol.

The background: About 15 minutes after we start eating, our guts begin releasing a hormone called “glucagon-like peptide-1 (GLP-1).” In addition to increasing the release of insulin, this also acts on the brain in a way that decreases appetite.

GLP-1 agonists are drugs that mimic this hormone, and several have been approved by the FDA as treatments for diabetes and, more recently, obesity.

What’s new? Some people taking GLP-1 agonists have reported that the meds curb their appetites for more than just food — they’ve also experienced a decreased desire for drugs and alcohol.

At least nine clinical trials are in the works to assess the potential of GLP-1 agonists as addiction treatments.

Experiments in animals suggest there’s something to these anecdotal reports. Some studies have found that rats taking GLP-1 agonists were less likely to seek out opioids and nicotine, while others determined that rodents and monkeys chose to drink less alcohol when they were taking the meds.

Now, at least nine clinical trials are in the works to assess the potential of GLP-1 agonists as addiction treatments in people.

How they (might) work: Researchers don’t know for sure how these meds might curb addictive behavior, but they suspect it has something to do with the release of dopamine, a chemical linked to feelings of pleasure.

When we first start eating something tasty, drinking alcohol, or taking recreational drugs, it triggers the release of dopamine in the brain. This makes us feel good, so we continue the behavior. 

Based on the preclinical studies, it appears GLP-1 agonists might prevent or slow this release. As a result, there’s no drive to consume more.

“The drug talks with our brain and says, ‘We’ve had enough food here. So let’s slow down. Let’s have less appetite. Let’s have less food, less alcohol,” Lorenzo Leggio, the clinical director of the National Institute of Drug Abuse, told NPR.

The cold water: GLP-1 agonists aren’t without drawbacks — there have been reports of rare but serious side effects in people taking them, and health regulators in Europe are currently investigating the possibility that the meds can trigger suicidal thoughts.

Newer GLP-1 agonists might be better at helping people combat drug or alcohol addictions.

Additionally, other GLP-1 agonists have already been tested as addiction treatments in people with less-than-stellar results.

In a small study of 13 people addicted to cocaine, a GLP-1 agonist didn’t appear to reduce cravings. A placebo-controlled trial involving 127 people addicted to alcohol found that the meds can curb drinking, but this was only in a subset of participants who were also obese.

Looking ahead: Those trials tested an older GLP-1 agonist (exenatide), and not the newer ones, such as semaglutide — these have proven to be more effective as weight-loss treatments, so it’s possible they might be better at helping people combat drug or alcohol addictions, too.

Even if GLP-1 agonists are only able to help certain people overcome certain addictions, that could still be hugely useful, and now that so many clinical trials are in the works, we should soon have a better idea of their true potential. 

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