Cordyceps is a type of medicinal mushroom said to offer antioxidant and anti-inflammatory benefits. Long used in traditional Chinese medicine, cordyceps is available in the United States as a dietary supplement.
There are 400 species of cordyceps, most of which are native to Bhutan, China, Korea, Nepal, Thailand, and Vietnam. The most well-known medicinal species is Cordyceps sinensis (now known officially as Ophiocordyceps sinensis). The mushroom has a long, finger-like body and is usually a brown or orangish-brown color.
So valued is wild cordyceps in China that a kilogram often costs in excess of $20,000. Most supplements today are made from an engineered fungal culture that has the biological characteristics of C. sinesis but cannot produce the mushroom itself.
Cordyceps is often referred to as the caterpillar fungus because of its thin, tubular shape. In traditional Chinese medicine, it is called dong chong xia ca.
In alternative medicine, cordyceps is often touted as a natural energy booster. Proponents also claim that cordyceps can protect against health problems like asthma, depression, diabetes, fatigue, high cholesterol, and upper respiratory tract infections.
Cordyceps is also purported to boost athletic performance, a claim that grabbed headlines in 1993 when Chinese track and field athletes shattered multiple world records, a feat their coach attributed to C. sinesis supplements.
Some herbalists also believe that cordyceps can boost libido, slow the aging process, and protect against cancer. Few of these claims are strongly supported by research.
Thus far, research into the performance-enhancing effects of cordyceps has yielded mixed results.
In a 2010 study published in the Journal of Alternative and Complementary Medicine, a daily cordyceps supplement appeared to improve exercise performance, albeit modestly, in a small group of older adults, ages 50 to 75.
Meanwhile, a 2016 study from the University of North Carolina at Chapel Hill showed that daily cordyceps supplementation gradually increased the maximum oxygen intake (VO2 max) in young adults after three weeks.2 What it didn't change was the time to exhaustion (TTE) or the stage in exercise when breathing becomes labored (ventilatory threshold).
In short, an improvement in oxygen consumption didn't translate to improved performance. It is unclear whether long-term supplementation might further improve upon these results.
Cordyceps has long been used as a traditional treatment for diabetes in China. While there are few quality studies investigating these effects in humans, several animal studies have been conducted, usually with disappointing or inconclusive results.
A 2012 study from Taiwan reported that a four-week course of a cordyceps extract was able to improve cholesterol levels and reduce weight in diabetic mice but did nothing to alter blood sugar levels or improve insulin resistance.
Despite this, the researchers suggested that the benefits of weight loss in controlling diabetes may be significant. Moreover, an improved cholesterol profile is generally associated with increased insulin sensitivity.
Cordyceps are believed to have potent anti-inflammatory and antioxidant effects, both of which may help prevent or treat high blood pressure (hypertension). Many of these benefits have been attributed to a compound known as cordycepin, which is similar in molecular composition to adenosine. Like adenosine, cordycepin appears able to relax blood vessels, improving circulation and lowering blood pressure.
The same benefits may be extended to the respiratory tract, according to a 2017 study from China. When taken daily, a cordyceps extract appears to relax airway constriction and improve quality of life measures in people with moderate to severe asthma.
Preliminary studies suggest that cordyceps may offer protection against certain types of cancer.
According to a 2008 study published in the Journal of Microbiology and Biotechnology, a cordyceps extract was able to trigger apoptosis (cell death) in breast cancer cells in test tube studies.
Similar results have been seen with colon cancer cells. The cordycepins in the cordyceps mushroom also appear to be toxic to leukemia cells
Cordyceps is considered safe for short-term use. Some users may experience mild side effects, including stomach ache, nausea, diarrhea, or dry mouth.7 Symptoms typically resolve once the treatment is stopped. Other have reported a lingering metallic taste after using a cordyceps product, which may take longer to resolve.
Despite its relative safety, the action of the herbal medication is poorly understood and may cause problems in certain users. If you are allergic to molds or yeast, you will likely be allergic to cordyceps and should steer well clear of them.
People on diabetes medications may need to avoid cordyceps as the combined use may result in an extreme drop in blood sugar (hypoglycemia).
People with bleeding disorders or who take anticoagulants ("blood thinners") or anti-clotting drugs may need to avoid cordyceps as well. Taking them together may increase the risk of bleeding or easy bruising.
This also applies if you are scheduled to undergo surgery. You would need to stop taking cordyceps at least two weeks beforehand to prevent excessive bleeding.
Little is known about the long-term safety of taking cordyceps. While the supplements are assumed to be safe, there remain concerns about the general safety of imported traditional Chinese medications.
Due to the lack of research, cordyceps products of any sort should not be used in children, pregnant women, or nursing mothers.
In the United States, cordyceps is usually available in capsule, tablet, or powder formulations. Dried whole mushrooms can often be found online, although you can't always be sure if you're getting C. simensis or a related cordyceps species.
Dried whole cordyceps are often used to make tinctures and extracts, while powdered cordyceps can be blended into smoothies and protein shakes or brewed into tea.
There are no universal guidelines for the appropriate use of cordyceps or cordyceps supplements. As a rule of thumb, never use more than the recommended dosage on the product label. If you develop any unusual symptoms after consuming cordyceps, stop and let your doctor know. Be sure to keep the product packaging to show the doctor.