A 20-cent “wonder drug” may do more than manage blood sugar.

Researchers are investigating whether a widely used diabetes medication could aid in the fight against colorectal cancer after the disease strikes. 

Scientists are cautiously optimistic that this decades-old pill could provide a new lifeline to the 150,000 Americans diagnosed with colorectal cancer each year — a growing number of whom are under 50.

What is this “wonder drug”?

Metformin is one of the most widely prescribed drugs on the planet. An estimated 200 million people worldwide take it daily, primarily to treat or prevent type 2 diabetes, according to UCHealth.

It’s best known for its ability to improve how the body handles insulin, helping lower blood sugar levels — but it’s often hailed as a “wonder drug” by doctors for having many other benefits, including treating fertility issues and PCOS.

Studies show that it may also combat obesity, provide anti-aging effects, and protect the cardiovascular and nervous systems. It might even have anti-cancer properties.

The metformin-cancer connection

Previous research indicates that metformin could offer a protective effect against the development of colon cancer.

For instance, a meta-analysis of 58 studies found that metformin use was associated with a 37% lower risk of developing the disease compared to type 2 diabetes patients who didn’t take the drug.

Now, researchers at The Ohio State University are diving deeper, exploring whether metformin could be used in treatment plans once colon cancer has already developed.

“Metformin seems like it could have a really interesting supplemental approach to therapy,” Holli Loomans-Kropp, the lead researcher, told Business Insider. “We’re opening up some doors to what this could do.”

Cheap drug, big potential

Presented last week at the American Association for Cancer Research conference in Chicago, the ongoing study focuses on how metformin interacts with colon cancer cells that are particularly difficult to treat. 

Early lab tests suggest that metformin has the potential to slow the growth of cancer cells. Researchers believe this could be connected to how the drug functions in diabetics.

Metformin regulates glucose production and triggers a “cleanup process” that helps eliminate damaged cells — an energy shift that may make it harder for colon cancer cells to develop. 

“If metformin maybe can be used to redirect or change how the cell uses energy, which then ultimately changes how it divides and how it proliferates, this could be a mechanism to exploit,” Loomans-Kropp said.

Scientists noted that while metformin doesn’t seem potent enough to treat colon cancer on its own, it could eventually be used to enhance other, more aggressive therapies.

An added bonus: Metformin is generally well tolerated and boasts a safety record that spans more than 60 years, according to Healthline.

When side effects do occur, they’re typically gastrointestinal, including nausea, diarrhea and abdominal discomfort.

The drug can also reduce vitamin B12 absorption and slightly increase the risk of lactic acidosis, a rare but serious condition where the blood becomes too acidic.

Another perk? It’s an off-patent, generic drug that costs just 10 to 20 cents per pill, making it widely accessible — even for patients without insurance.

The road ahead

The ongoing study by researchers at The Ohio State University is still in its early stages.

Loomans-Kropp told Business Insider that if initial results from cancer cell tests are promising, she hopes to begin testing metformin as a colon cancer treatment on animals within the next year.

Colon cancer is widely considered a pressing public health concern, as it’s one of the leading causes of cancer deaths worldwide.

While the overall incidence has been dropping, particularly among older adults, there has been a troubling rise in cases and deaths among younger people in recent years.

In fact, colon cancer is now the leading cause of cancer death in American men under 50 and the second leading cause for women in the same age group.