A recent study by scientists at Johns Hopkins Medicine has found that a drug originally designed for other medical conditions may help treat severe obesity and improve heart health—without requiring changes in diet or exercise.
This early-stage research, though still limited to animal studies, could pave the way for new treatment options for obesity, a growing global health problem.
Today, there is no approved pill that can reliably treat severe obesity on its own. Obesity affects over 40% of adults in the United States and is linked to serious health issues like heart disease, diabetes, and fatty liver disease.
For women over 60, the number is even higher—around 43%. Because of its connection to so many health risks, scientists have long searched for effective ways to help people manage their weight safely.
In this study, researchers focused on a type of drug known as a PDE9 inhibitor. These drugs are still experimental, meaning they are not yet approved for public use.
They work by blocking a protein in the body called PDE9, which plays a role in how cells respond to signals related to blood pressure and metabolism. This protein is similar to another one, PDE5, which is targeted by drugs like Viagra.
Back in 2015, the same research team discovered that the PDE9 enzyme is found in the heart and may contribute to heart damage caused by high blood pressure. Since then, they have continued exploring whether blocking this protein could help treat other health problems, including obesity.
To find out, the researchers tested a PDE9 inhibitor developed by Pfizer, called PF-04447943. This drug was originally created for Alzheimer’s disease but was later abandoned for that use. However, in past clinical trials, more than 100 people received the drug, and it appeared to be safe, with no serious side effects reported.
In the current study, the team gave the drug to mice that had developed obesity due to a high-fat diet. Even though the mice continued eating the same amount of food and remained inactive, they lost a significant amount of body fat, especially around their waist. They also showed improvements in heart function and a reduction in fat buildup in the liver.
If these findings hold true in humans, the results could be dramatic. A person weighing 250 pounds might be able to lose around 50 pounds with this drug, without needing to change how much they eat or exercise. Of course, more research is needed to confirm these effects in people.
The drug works by influencing a natural chemical in the body called cyclic GMP, which helps regulate how cells function. By blocking PDE9, the drug allows more of this helpful chemical to remain active, which appears to improve metabolism, reduce fat, and support heart health.
It’s important to note that while these results are promising, PDE9 inhibitors are still in the experimental stage. A different version of this type of drug is currently being tested in humans for heart failure, which may provide more insight into how safe and effective these medications really are.
This research offers hope for a future where obesity might be treated with a simple pill, especially for people who have struggled to lose weight through diet and exercise alone. The study was led by Dr. David Kass and published in the Journal of Clinical Investigation.
If you care about weight management, please read studies about diets that could boost your gut health and weight loss, and 10 small changes you can make today to prevent weight gain.
For more information about obesity, please see recent studies about low-carb keto diet could manage obesity effectively and results showing popular weight loss diet linked to heart disease and cancer.
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