How a Backyard Flower Inspired One of the World’s Most Prescribed Drugs

Goat’s rue, a backyard flower, was used to treat symptoms of diabetes centuries ago. The plant paved the way for metformin.

Goat’s rue, sometimes known as French lilac or by its scientific name, Galega officinalis, is a garden plant that does more than just look pretty. For centuries, it was used to treat diabetes — and it became the blueprint for metformin. Now one of the most commonly prescribed drugs around the world, metformin is typically used to treat or prevent type 2 diabetes. Here’s how goat’s rue inspired metformin.

What You Should Know About Goat’s Rue and Metformin

Goat’s rue is a flowering perennial that thrives in wetlands and near riverbanks, and is classified as an invasive weed in the United States. Centuries ago, the plant was used to help combat what was then known as sweet urine disease. It turns out the active ingredient in the plant was galegine. It was eventually discovered this ingredient can help lower blood glucose levels, but may have toxic side effects — so it’s not used or suggested as a home remedy today.

Eventually, chemists used it as the template for synthetic metformin, a modern drug that helps control blood sugar — without galegine’s toxicity. Though widely prescribed today as a treatment for diabetes, it was distrusted for years — and even banned in some countries — because of its link to the toxic guanidine family. Now, nearly 70 years after it was first introduced as a treatment for type 2 diabetes, metformin is the most prescribed glucose lowering medicine worldwide, and researchers are just learning about the potential this drug has.

Going Deeper: From Folk Remedy to ‘Super Drug’

While goat’s rue was used during medieval times to treat everything from seizures to fever to symptoms we associate with diabetes today, it wasn’t until the early 1900s that scientists discovered how galegine and related compounds in the plant worked to lower blood sugar. First discovered in 1922, metformin is typically taken as a pill to help manage type 2 diabetes. It wasn’t until 1957 that metformin began to be used to treat diabetes, and the drug didn’t become FDA-approved until 1994. Now, clinical trials show it’s one of the safest and most effective ways to treat and prevent type 2 diabetes.

Beyond diabetes, researchers are studying other uses for the goat’s rue-inspired drug. Early research suggests it may have anti-cancer effects. The drug is also sometimes used to support weight loss, treat prediabetes, and support fertility, especially in those with PCOS. Some in vitro studies and those done in animals shows there may be potential to support heart health, though human-specific research is needed. Researchers are also looking into metformin’s potential to lower risks tied to cognitive decline and strokes, and support a longer life expectancy.

Currently, exactly how metformin produces these wider effects isn’t fully understood, but researchers are working to figure out more — and potentially discover more useful applications for the drug.

The Takeaway

Centuries ago, people used extract from the French lilac found in their gardens to treat what we now know as diabetes. This plant inspired one of modern medicine’s most useful drugs: metformin. Though currently most well-known for its use in treatment or prevention of type 2 diabetes, scientists are still uncovering what metformin can do beyond that. Studies show metformin may be useful for reducing the risk of some cancers and cardiovascular disease, and even the potential for supporting a long, healthy lifespan. 

Bottom Line

The active ingredient in goat’s rue, galegine, inspired one of the most effective and widely prescribed drugs for treating type 2 diabetes and other illnesses. Metformin, often hailed as a “wonder drug” is taken by an estimated 150 million-plus people daily. What’s more, emerging research is discovering benefits and disease treatment of the prescription medication beyond blood sugar benefits for those with type 2 diabetes.