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Cordyceps

Cordyceps explained: cultivated Cordyceps militaris versus wild caterpillar fungus (Ophiocordyceps sinensis), what small trials found, bleeding and blood sugar cautions, and conservation.

Content last updated . This page has not been medically reviewed.

Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.

Safety first. Memorial Sloan Kettering Cancer Center (MSK) advises talking with your healthcare provider if you take insulin or other blood sugar medicines (cordyceps may also lower blood sugar) or a blood thinner such as warfarin (it may raise bleeding risk). [1] It also notes a case report of excessive bleeding after a tooth extraction in a person using cordyceps daily as a tonic, and says cordyceps should not be used by people with myelogenous types of cancer, based on animal findings. [1] Tell the surgical or dental team about any cordyceps product before a procedure. See medicine interactions and cordyceps side effects and medicine cautions.

Two different fungi share one name

"Cordyceps" on a label can mean two species, and trial results do not transfer from one to the other.
  • Cordyceps militaris (L.) Fr. is an accepted species in the family Cordycipitaceae. [2] Trials of a fermented drink and of capsules named it. [3][4]
  • Ophiocordyceps sinensis (Berk.) G.H.Sung et al. is the accepted name of the wild "caterpillar fungus" in the family Ophiocordycipitaceae. [5] MSK says it was renamed in 2007 and that it is a parasitic fungus that grows on moth larvae. [1] Older papers and product names often still say Cordyceps sinensis.

The wild product is the fungus together with the caterpillar body it grew from, and one study analyzed those two parts separately. [6] Supplements can be made from other materials, so the label matters. See the species question and cordycepin.

Traditional use

Traditional use only, not proof. MSK says the wild fungus is used in traditional Chinese medicine for a wide range of conditions including fatigue, sexual dysfunction and coughs. [1] A Korean trial report describes C. militaris as traditionally used for diverse purposes in East Asia, including China. [4]

What research shows

UseWhat the source foundStrength of evidenceSpecies, form, population
Exercise capacityA 12-week placebo-controlled pilot (20 healthy people aged 50 to 75) reported a 10.5% rise in the metabolic threshold; maximum oxygen uptake did not change. [7]Promising but limited (pilot)"Cs-4" product named as C. sinensis, 333 mg three times daily
Exercise in younger adultsA 2026 narrative review of 5 studies (321 people aged 16 to 35) found inconsistent results and limited certainty. [8]MixedC. militaris, various products, some multi-ingredient
Immune markersIn a 4-week trial of 79 healthy men, natural killer cell activity and some cytokines rose more than with placebo. [4] A smaller 8-week trial of a fermented drink in healthy adults reported higher natural killer activity in some groups. [3]Biomarker change only; no clinical outcome shownC. militaris capsules (1.5 g/day) and a drink (2.85 mg cordycepin)
Kidney diseaseMSK says some studies suggest benefit in transplant recipients, but several analyses found the evidence insufficient. [1]Insufficient evidenceO. sinensis products
CancerMSK lists antitumor effects from preclinical studies. [1]Preclinical (cells or animals)Laboratory models

MSK also notes that exercise-performance studies in healthy people gave mixed results. [1] Detail: cordyceps for energy and exercise.

Forms and why the form matters

Capsules of cultured mycelium, a fermented drink and the wild caterpillar fungus are different materials. A chemistry study of strains of both species grown on rice substrates found that the main compound in two of the four extracts, one from each species, was the same polyglucan. [9] Two products with the same word on the label can still differ in species, strain and growing material. Check whether a label names the species, part and extract method; see how to read a label. A clinician or pharmacist decides what is right for a person; amounts here only describe trials.

Wild harvest and conservation

Himalayan caterpillar fungus has become one of the world's most valuable biological commodities, supporting income for hundreds of thousands of collectors, and a 2018 study found production had fallen from overexploitation and climate change according to collectors across four countries. [10] Cultivated C. militaris products avoid that pressure, but a label must say which species it contains. See wild harvest and conservation.

Official statements

The National Cancer Institute's PDQ mushroom summary (2024) says the US FDA has not approved medicinal mushrooms as a treatment for cancer or any other medical condition. [11]

Frequently asked questions

Is cordyceps the same as the caterpillar fungus?

Only sometimes. The wild caterpillar fungus is Ophiocordyceps sinensis; most cultivated products are Cordyceps militaris, though labels may say only "cordyceps". [5][2]

Does cordyceps improve athletic performance?

Results are mixed. One small pilot in older adults raised a threshold measure; a review of younger adults found inconsistent findings. [7][8]

Can cordyceps affect blood sugar medicine?

MSK advises asking your healthcare provider if you take insulin or other blood sugar lowering medicines. [1]

Does cordyceps support immunity?

Small trials show changes in immune test values in healthy people, but they did not measure illness. [4][3]

Is the wild fungus endangered?

A 2018 study reports declining production from overharvesting and climate change. [10] MSK notes the wild fungus is used in traditional Chinese medicine as an adaptogen or immune stimulant; see what adaptogens are for how that word is used. [1]

More details: evidence, limits and cautions

The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.

Safety in more detail
  • Common effects: MSK lists no major side effects reported. [1]
  • Blood sugar and bleeding: see the safety box above; clinical relevance of the lab findings is not known. [1]
  • Heavy metals and arsenic: a study of wild O. sinensis samples from Qinghai found high total arsenic, though only 8.69% was the more toxic inorganic form, and concluded no obvious risk in a reasonable manner of taking; the samples were few and not retail supplements. [6] See heavy metals and contamination.
  • Pregnancy, breastfeeding and children: not described in the sources we read. See pregnancy and breastfeeding.
  • Liver and kidney: liver safety was not described in the sources we read for cordyceps. Ask a clinician if you have liver or kidney disease. See liver safety.
References
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.