Educational information, not medical advice — ask your doctor or midwife.
Ophiocordyceps sinensis is a fungus that grows out of a buried caterpillar high on the Tibetan plateau. It is sold as a tonic for energy, stamina, and lung and kidney health. Human evidence for those uses is thin and mostly weak.
It is also called caterpillar fungus, yarsagumba and dong chong xia cao. In the wild it infects moth larvae, kills them, then pushes a thin brown stalk above the soil. Wild stock is rare and costly.
Because of that cost, most capsules do not hold the wild fungus at all. They hold lab-grown mycelium (the root-like body of a fungus) or a fermented powder known as CS-4. These are related products, not the same thing.
Long use in a tradition tells you that people valued this fungus. It does not show that the fungus works. It also does not show that it is safe.
No one has shown how this fungus acts inside the human body. Almost all of the mechanism talk comes from cell and animal work.
In lab studies, its sugar-like compounds appear to stir immune cells and to mop up free radicals. In animals, extracts have been linked with better use of oxygen by muscle. Whether either happens in people is not established.
One named compound, cordycepin, slows cell growth in test tubes. The wild fungus holds very little of it. A related species, Cordyceps militaris, holds much more, so lab findings on cordycepin may not apply here.
Sellers often call it an adaptogen, meaning a herb said to help the body cope with stress. That label is a marketing term. It is not backed by firm human trials.
Most products on sale are lab-grown rather than wild. Common forms include:
- Whole dried fungus, sold by weight, often at a very high price. - Plain powder in capsules or tablets. - Hot water or alcohol extracts, marked with ratios such as 8:1.
- CS-4, a fermented mycelium powder used in several trials. - Tinctures, teas, broths, and coffee or cocoa blends.
Fakes are common at the wild end of the market. Sellers have been caught padding stalks with lead wire or glue to raise the weight. Lab tests have also found lead and arsenic above safe limits in some wild samples.
Many products labelled cordyceps hold Cordyceps militaris instead. That is a cheaper, farmed species with a different chemistry.
Healers in Tibet and Nepal used this fungus long before it reached Chinese medicine. A Tibetan medical text from the 15th century describes it. Chinese works list it from the 18th century, during the Qing period.
In Chinese medicine it was classed as a warm tonic for the lung and the kidney. Healers gave it after long illness, for a lasting cough, for tiredness and for low sex drive. It was often stewed with duck or chicken rather than taken as a pill.
Its modern fame grew after 1993, when Chinese runners who used it broke world records. Demand and prices then rose sharply. Wild stock is now scarce, and harvest rights are fought over in Nepal, Bhutan, India and China.
Get emergency help if you have swelling of the lips, face or throat, a spreading rash, or trouble breathing. Those can be signs of a severe allergic reaction.
Stop and call your doctor if you notice any of these:
- Unusual bruising, nosebleeds, blood in your urine, or black stools. - Yellow skin or eyes, or dark urine. - Shaking, sweating or confusion, if you treat diabetes. - Any new swelling, poor urine output or rising blood pressure, if you have kidney disease. - Stomach upset or loose stools that last more than a few days.
If you have a transplant, tell your team at once if you have taken it.
In the United States it is sold as a dietary supplement. The FDA does not check such products for effect before sale. In the UK and EU it is sold as a food supplement, and health claims are not approved.
Wild harvest is controlled in China, Nepal, Bhutan and India. The species is listed as vulnerable because of over-collection.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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