The fungus Cordyceps first made international headlines in 1993, when female Chinese runners decimated world records in a major competition. Their coach attributed this remarkable athletic performance to the use of caterpillar fungus, or Cordyceps.

It’s enjoyed growing popularity among athletes eager to boost their performance and stamina. Today, it’s widely available in the United States as a nutritional supplement, in pill form, and as a tonic. It’s also touted as having a broad range of health benefits.

The Caterpillar Fungus

Cordyceps is not your typical friendly grocery store mushroom. It’s a fungus that attaches itself to a caterpillar and uses the carcass as food. It then shoots out Medusa-like stems that yield spores looking for their own hosts. In a way, it‘s both a fungus and a caterpillar, because the caterpillar plays an important role in the end product.

Cordyceps grows in the higher altitudes of the Himalayas and Tibetan plateau, and has been prized as a medicine for centuries in Tibet and China. Although it was used to treat a number of ailments, Cordyceps was also highly regarded as an aphrodisiac. Because of its astronomical cost, it was used only by the very wealthy.

What Are the Health Benefits of Cordyceps?

The evidence that Cordyceps can boost exercise performance is somewhat limited. Researchers at Brigham Young University studied the effects of Cordyceps on endurance-trained cyclists. They concluded that the fungus does not increase aerobic capacity or exercise performance.

However, there are several other health claims linked to Cordyceps. Let’s look at a few of the most common.

Reduces Inflammation

Scientists at the University of Nottingham in Britain have been researching the potential of Cordyceps to reduce inflammation. While their research shows the fungus is effective at reducing inflammation at the cellular level, it has not been tested on humans or animals.

Protects the Heart

A number of research studies show that Cordyceps has potential for treating heart disease. It is approved in China to treat arrhythmia. Talk to your doctor before you consider taking a supplement for any condition.

Slows Kidney Disease

In a 2011 study, researchers at Zhejiang University found that Cordyceps cicadae “may inhibit renal fibrosis” in rats. Renal fibrosis is a condition found in the later stages of kidney disease. Further study is needed.

Slows Tumor Growth

A number of studies on animals indicate that Cordyceps may slow the growth of tumors from certain types of cancer. One theory is that it can stimulate the immune system to fight the cancer. No human testing has been done.

Revs Up Libido

Several studies show that Cordyceps increases testosterone in rats, but there are no credible human trials that indicate the fungus enhances libido or sexual performance.

Under the Microscope

Prices for Cordyceps have soared to $50,000 per pound. This is due to growing demand coupled with the fact that this particular fungus is difficult to grow commercially. As a result, the market has been flooded with products that contain other species of Cordyceps, rather than Cordyceps sinensis, the fungus with the long history of medicinal use. No benefits have been associated with these other species.

Limited research does support certain health benefits of Cordyceps when added directly to a cell or when tested in animals, but there have been few tests on humans. Until human studies support the use of this supplement, there is no proof of effectiveness.

Among the detractors are the NYU Langone Medical Center, who reports that there is no credible scientific research to support the many health claims or the notion that it improves sports performance.