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Cordyceps benefits are promoted mainly for energy and stamina, but the human evidence is small and mixed. Cordyceps is a group of fungi that grow on insects. The traditional form, now called Ophiocordyceps sinensis and long known as Cordyceps sinensis, grows on moth caterpillars high on the Qinghai-Tibetan Plateau and has been used in Asian medicine since at least the fifteenth century. Because the wild fungus is rare, most supplements use cultivated preparations or the related species Cordyceps militaris. Here is what cordyceps is, what trials found, its side effects and which medicines call for caution.
Peptide Labs sells no cordyceps products, and this article does not recommend any product. It is general information, not medical advice.
Key Takeaways
- Ophiocordyceps sinensis is a fungus that grows on moth larvae; Cordyceps militaris is a related species produced commercially.
- Wild cordyceps is rare and among the most expensive traditional medicines, so cultivated forms dominate supplements.
- Exercise trials are small and mixed: one found no effect in trained cyclists, and two small trials reported modest changes.
- Memorial Sloan Kettering reports no major side effects, but cordyceps may lower blood sugar and add to bleeding risk.
- Claims about immunity, kidneys or sex drive rest mostly on lab, animal or low-quality studies.
What is cordyceps?
Memorial Sloan Kettering Cancer Center (MSKCC) describes cordyceps as a fungus that grows on the caterpillar of a moth. Its common names include Chinese caterpillar fungus, dong chong xia cao and yarsha gumba. In traditional Chinese medicine it has been used for fatigue, coughs and sexual problems, and as an adaptogen or immune tonic. The species was renamed Ophiocordyceps sinensis in 2007, though many labels still say Cordyceps sinensis.
A 2014 review explains why the wild fungus is so prized: it appears only at high altitudes on the Qinghai-Tibetan Plateau, it is hard to find and harvest, and it has long been one of the most expensive medicines known. Seasonal harvesting by thousands of collectors has strained fragile alpine grasslands, which has pushed efforts to cultivate it. As a result, products sold as cordyceps are usually made from fungus grown in controlled conditions, sold as capsules, powders and liquid extracts.
Cordyceps militaris vs Cordyceps sinensis
Two names dominate supplement labels. They are related fungi, but they are not the same species, and most research has been done on one or the other rather than both.
| Feature | Ophiocordyceps sinensis (Cordyceps sinensis) | Cordyceps militaris |
|---|---|---|
| Where it comes from | Wild on moth larvae on the Qinghai-Tibetan Plateau, or cultivated preparations | Grown commercially, including by fermentation |
| Compound most discussed | Cordycepin and polysaccharides | Cordycepin, a major bioactive component |
| Availability | Wild form is rare and highly prized | Widely produced |
| Human trials | Small exercise trials of a commercial Cs-4 preparation; kidney transplant trials in China | One small exercise trial of a mushroom blend |
Cordycepin is one of the compounds researchers study most. A 2022 review notes that commercial cordycepin is mainly isolated from fermented Cordyceps militaris. Lab findings about cordycepin do not tell you what a capsule does in a person, which is why the human trials below matter.
Cordyceps benefits: what the research shows
MSKCC lists immune support, kidney function, and strength and stamina as the main promoted uses, and notes that exercise studies in healthy people have produced mixed results. Here is what the trials actually tested.
Exercise and stamina
- Trained cyclists, no effect: a 2004 Brigham Young University trial gave 22 endurance-trained male cyclists a commercial cordyceps preparation called Cs-4 or placebo for five weeks. Peak oxygen uptake, ventilatory threshold and time-trial performance did not change.
- Older adults, modest changes: a 2010 UCLA pilot trial in 20 healthy adults aged 50 to 75 found that, after 12 weeks of Cs-4, two measures of when fatigue sets in during cycling improved by about 8 to 11 percent, while maximal oxygen uptake did not change in either group.
- Young adults, a mushroom blend: a 2017 University of North Carolina trial tested a blend containing Cordyceps militaris in 28 young adults. After one week there were no significant differences from placebo. Only ten people continued to three weeks, when oxygen uptake improved in the blend group. Because it was a blend, the effect cannot be credited to cordyceps alone.
Taken together, these are small, short studies with mixed results and no independent replication of the positive findings. They do not show that cordyceps improves athletic performance. For a supplement with a far larger evidence base, see our creatine guide; our guides to rhodiola and ginseng look at other herbs marketed for energy.
Kidney research
In China, cordyceps has been used as an add-on for kidney transplant recipients. A 2015 Cochrane review found five studies with 447 participants, all with unclear risk of bias and short follow-up. Compared with one older drug, cordyceps showed no difference in graft or patient survival, though some lab measures looked better, and the reviewers urged caution and longer studies. MSKCC notes that other analyses found the evidence insufficient for transplant and dialysis patients. These are findings from supervised hospital care, not a reason to add cordyceps on your own.
Blood sugar, immunity and hormones
Lab and animal studies suggest cordyceps can lower blood sugar, act on immune cells and raise testosterone production in mice. Human data are thin. In a 2016 double-blind trial, 84 adults with type 2 diabetes and metabolic syndrome took reishi with or without cordyceps, or placebo, for 16 weeks, and neither combination changed blood sugar or any other measured outcome. MSKCC says it is not known whether the hormone effects seen in mice occur in people, so consider sex drive and testosterone claims on labels unproven.
Cordyceps side effects and drug interactions
MSKCC reports that no major cordyceps side effects have been documented, but it flags several situations where caution matters.
- Diabetes medicines: talk with your clinician if you take insulin or another glucose-lowering drug, because cordyceps may lower blood sugar further.
- Blood thinners: cordyceps may increase bleeding risk with drugs such as warfarin. In lab studies, cordycepin reduced platelet clumping, and MSKCC cites a case of excessive bleeding after a tooth extraction in a person who used cordyceps daily as a tonic. Tell your dentist or surgeon before any procedure.
- Blood cancers: based on animal data showing growth of red blood cell precursors, MSKCC advises that people with myelogenous blood cancers should not use cordyceps.
- Transplant and immune medicines: because cordyceps has been studied alongside transplant drugs, do not combine it with immune-suppressing medicines unless your transplant team agrees.
- Pregnancy and breastfeeding: we found no human safety data, so avoid it unless your clinician advises otherwise.
How to read a cordyceps label
A clear label names the species, Ophiocordyceps sinensis (or Cordyceps sinensis) or Cordyceps militaris, says whether the product is a cultivated preparation, whole fungus or an extract, and shows a full Supplement Facts panel. Because the wild fungus is rare, be cautious with products that imply they contain wild-harvested cordyceps without saying how it was sourced. Claims that cordyceps boosts immunity against illness, restores kidney function or raises testosterone are not supported and are not allowed on supplement labels.
Cordyceps also appears in many mushroom blends, often alongside lion’s mane, chaga and reishi; our guide to mushroom coffee covers those products. Independent testing helps confirm identity and screen for contaminants, so see our guide to third-party tested supplements. For a far more familiar plant with a much larger body of research, read our green tea guide.
Frequently Asked Questions
What are the main cordyceps benefits?
Cordyceps is promoted for energy, stamina and immunity. Human trials are small and mixed: one found no effect in trained cyclists, and two small trials reported modest changes in exercise measures.
What are cordyceps side effects?
MSKCC reports no major side effects, but cordyceps may lower blood sugar and increase bleeding risk, and one case of excessive bleeding after a tooth extraction has been reported.
What is the difference between Cordyceps militaris and Cordyceps sinensis?
They are related fungi. Cordyceps sinensis, now Ophiocordyceps sinensis, grows wild on moth larvae in the Tibetan highlands and is rare; Cordyceps militaris is produced commercially and is a main source of cordycepin.
Does cordyceps improve exercise performance?
The evidence does not show that it does. A trial in trained cyclists found no effect, and the positive studies were small, short and in one case used a mushroom blend.
Can I take cordyceps with blood thinners or diabetes medicines?
Talk to your prescriber first. MSKCC warns cordyceps may add to the effects of warfarin and of insulin or other glucose-lowering drugs.
Is cordyceps safe?
Short-term use has not been linked to major side effects, but long-term safety, pregnancy safety and product quality are not well studied, and some people should avoid it.
Questions about a label? Contact us or read our Buyer’s Guide. Follow the label and ask a healthcare provider before starting any supplement, especially if you take medicines or are pregnant. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Last reviewed October 2026.
Related guides: Reishi Mushroom Benefits: Evidence, Liver Safety and Warfarin, Lion’s Mane: What the Research Shows and Side Effects, Beta-Alanine: Benefits, Tingling Side Effect and Research.