Cordyceps militaris vs Cordyceps sinensis: Species, Cordycepin and Sourcing

"Cordyceps" on a label can mean three different things: wild Ophiocordyceps sinensis (the Himalayan caterpillar fungus), fermented mycelium strains such as Cs-4, or cultivated Cordyceps militaris. They differ in taxonomy, chemistry and price. Human evidence for all three is limited, so knowing which one you are buying matters.

This guide explains the names, the compound cordycepin, and what to check when sourcing any Cordyceps product.

Why Is "Cordyceps" Such a Confusing Name?

For most of the 20th century, hundreds of insect-parasitising fungi were grouped in one genus, Cordyceps. A large 2007 DNA study showed that grouping was wrong. The authors split the genus. Cordyceps militaris stayed as the type species of the family Cordycipitaceae. Many darker, tougher species, including the caterpillar fungus, moved to a new genus, Ophiocordyceps (Sung et al., Studies in Mycology, 2007).

So "Cordyceps sinensis" is now correctly called Ophiocordyceps sinensis. It grows on moth larvae in high-altitude grasslands of the Tibetan Plateau and the Himalaya. It is one of the most valuable biological commodities in the world. A 2018 study combining collector interviews and ecological models found that its production is declining because of overharvesting and climate change (Hopping et al., PNAS, 2018).

Cordyceps militaris is different in practice. It forms bright orange fruiting bodies and can be cultivated, usually on grain-based substrates and sometimes on silkworm pupae. That makes it far cheaper and more consistent than wild caterpillar fungus.

What Is Cordycepin, and Which Species Has It?

Cordycepin (3'-deoxyadenosine) is a small molecule closely related to adenosine, one of the building blocks of RNA. It is the compound most often named in Cordyceps marketing.

A 2021 review of C. militaris describes cordycepin as a key constituent of its fruiting bodies and cultured mycelium, alongside polysaccharides, GABA and ergothioneine (Jędrejko et al., Foods, 2021). Most studies of cordycepin's biological effects are in cells or animals, not people.

Wild O. sinensis tells a surprising story. A 2019 comparison found that natural samples had lower average cordycepin and adenosine than cultivated ones, but higher mannitol and polysaccharides (Zhou et al., PLOS ONE, 2019). In other words, "wild" does not mean "more cordycepin", and cordycepin content alone does not define quality.

Which Form Was Used in the Research?

This is where many product pages mislead. Several human studies labelled "Cordyceps sinensis" did not use the wild fungus. Cs-4, the product in several older trials, is a fermentation product from a mycelial strain, Paecilomyces hepiali, originally isolated from wild C. sinensis (Chen et al., Journal of Alternative and Complementary Medicine, 2010). More recent exercise work has used C. militaris blends.

So a trial result for Cs-4 cannot be applied directly to C. militaris fruiting bodies, or the other way round. For what those exercise studies measured, see our piece on Cordyceps militaris and athletic performance.

Quality and Sourcing: What Should You Check?

High prices invite adulteration. In one Taiwanese report, two people developed lead poisoning after taking a Cordyceps powder that contained up to 20,000 ppm of lead (Wu et al., Science of the Total Environment, 1996). Useful questions for any seller:

• Which species is it, and is the Latin name on the label?
• Is it fruiting body, mycelium, or mycelium on grain?
• Has it been tested for heavy metals and microbial contamination?
• If cordycepin or adenosine content is claimed, is there a lab result?

Our Cordyceps militaris is sold as whole dried fruiting bodies, cultivated rather than wild-collected. We do not make health claims for it. For a general framework for judging mushroom products, see our mushroom product checklist and our overview of natural mushroom supplements.

Safety and Interactions

Memorial Sloan Kettering's clinical herb database, which focuses on C. sinensis products, lists these cautions (Memorial Sloan Kettering, About Herbs: Cordyceps, updated 2022):

• Blood thinners. Cordyceps inhibits platelet aggregation and may add to anticoagulant or antiplatelet drugs. One case of excessive bleeding after a tooth extraction is described.
• Diabetes medication. Lab studies suggest additive blood-sugar lowering.
• Transplant and immunosuppressant drugs. Anecdotal reports describe cordyceps changing cyclosporin-related kidney effects in transplant patients, so anyone on these drugs should check first.
• Myelogenous cancers. Avoidance is advised, based on animal findings.

There are no safety data for pregnancy or breastfeeding. If you take medication or have a health condition, talk to your doctor or pharmacist before using any Cordyceps product.

Frequently Asked Questions

What is the difference between Cordyceps militaris and Cordyceps sinensis?

Cordyceps sinensis is now called Ophiocordyceps sinensis, a wild caterpillar fungus from the Tibetan Plateau and Himalaya. Cordyceps militaris is a different species that can be cultivated, which makes it cheaper and more consistent.

What is cordycepin?

Cordycepin, or 3'-deoxyadenosine, is a compound closely related to adenosine. It is a key constituent of Cordyceps militaris. Most research on its effects has been done in cells or animals.

Does wild Cordyceps contain more cordycepin?

Not necessarily. A 2019 comparison found lower average cordycepin in natural Cordyceps sinensis samples than in cultivated ones, although natural samples had more mannitol and polysaccharides.

What is Cs-4?

Cs-4 is a fermentation product from the mycelial strain Paecilomyces hepiali, originally isolated from wild Cordyceps sinensis. It was used in several older human trials.

Who should avoid Cordyceps?

People on blood thinners, diabetes medication or immunosuppressants should ask a doctor first. Avoidance is advised for myelogenous cancers, and there are no safety data for pregnancy or breastfeeding.

This article is for educational purposes only and is not medical advice. It does not replace a consultation with a doctor or pharmacist, especially if you take medication, have a health condition, or are pregnant or breastfeeding.