A new study from Johns Hopkins Medicine has found something surprising: a drug that was first created to help people with Alzheimer’s disease, schizophrenia, and sickle cell disease may also help people lose weight and improve health—even if they don’t change what they eat or how much they exercise.
This could be big news, because severe obesity is a major problem around the world. It increases the chances of getting serious diseases like diabetes, heart disease, and fatty liver disease. But so far, no pill has worked well enough to treat severe obesity on its own. This new discovery might change that.
The scientists focused on something in the body called an enzyme. Enzymes are tiny proteins that help the body do important jobs. The enzyme in this study is called PDE9. It controls another small molecule in the body known as cyclic GMP.
This molecule helps with many important tasks inside our cells. You may have heard of a similar enzyme, PDE5, which is what Viagra works on.
Right now, there are no PDE9 drugs you can buy at the pharmacy. These types of drugs are still being tested. But researchers have been interested in PDE9 for years because they think it could help treat Alzheimer’s disease, heart problems, and more.
Back in 2015, researchers found PDE9 in the heart, where it seemed to make heart disease worse when blood pressure was high. That finding made the scientists wonder: what if stopping PDE9 could help with other health issues too, like obesity or high blood pressure?
To find out, the researchers tested a drug called PF-04447943, which was originally developed by the company Pfizer. This drug was made to treat Alzheimer’s disease, but it didn’t work well for that purpose. Still, it was tested in over 100 people and seemed safe, with no major side effects.
In the new study, scientists gave the drug to mice that were overweight and unhealthy. Even though the mice didn’t eat less or move more, they started losing weight. They also had healthier livers and better heart function. This suggests that the drug helped their bodies burn fat and work better, even without diet or exercise.
If the same thing happens in people, the results could be life-changing. For instance, someone who weighs 250 pounds might lose around 50 pounds just from taking the pill. But the drug might also do more than help people lose weight. It could protect the heart and liver, too, which are often harmed by obesity.
In the United States, more than 40 out of every 100 adults are obese. For women over 60, the number is even higher. Many people try to lose weight with diet and exercise but don’t succeed. This drug could offer a new way to help those people.
More studies are needed before this drug could be given to humans for obesity. But the early results are very promising. Another similar drug is already being tested in people who have heart failure. This means scientists are actively working on finding out how helpful these drugs can be.
The study was led by Dr. David Kass and published in the Journal of Clinical Investigation. It brings hope to millions of people who are struggling with weight and related health problems.
If you care about weight, please read studies about diet that can treat fatty liver disease, obesity, and hop extract could reduce belly fat in overweight people.
For more information about weight, please see recent studies about how to curb your cravings for ready-to-eat foods, and results showing what you can eat to speed your metabolism up.
Copyright © 2025 Knowridge Science Report. All rights reserved.
