© Lukas Large · CC BY-SA 2.0 · Commons
Scarlet caterpillarclub
CautionPuppen-Kernkeule · (Cordyceps militaris)
Cordycipitaceae (Cordycipitaceae)
Description
Cordyceps militaris is an orange-red sac fungus of the Cordycipitaceae. It lives as a parasite: its spores infect moth pupae and caterpillars in the soil, grow through them and in late summer push the club-shaped fruiting bodies, one to five centimetres tall, out of the forest floor. Anyone who finds one and digs carefully will strike the filled pupal case beneath it. In Central Europe the species is rare and locally red-listed; material on the market comes almost entirely from cultivation on rice or insect substrate. It should not be confused with the Tibetan caterpillar fungus Ophiocordyceps sinensis, which is far more expensive and a different species. Its signature constituents include cordycepin, adenosine and polysaccharides. In traditional Chinese medicine the fungus is valued as a strengthening remedy and is now marketed as an adaptogen; many of the promoted effects have so far only been described in laboratory and animal studies. No serious side effects are known; caution applies with blood thinners.
Critical drug interactions with:
Immunsuppressiva
Traditionally used in Chinese medicine as a tonic for fatigue and cough and to support lung and kidney function. The customary preparation is a long simmer of the dried fruiting bodies, often together with other ingredients in a soup.
Preparation & dosage
Put about 3 g of dried fruiting bodies into 500 ml of water and simmer gently for 30 to 45 minutes. The brew is pale orange and tastes mildly mushroomy.
- Dry amount
- 2–3 g
- Doses per day
- 1×
Marketed as an adaptogen claimed to improve stress resilience and reduce fatigue. Human exercise-performance studies are inconsistent and inconclusive; the constituent cordycepin has shown immunomodulatory effects in lab and animal studies without proven benefit in humans. What a given supplement actually contains varies considerably — many products consist of colonised grain substrate rather than fruiting bodies, with correspondingly less cordycepin.
Unlike the Tibetan caterpillar fungus, Cordyceps militaris can be cultivated — on cooked rice with added nutrients, in jars under light. That is exactly what turned it from a collector's find into a traded commodity and made research on it possible in the first place. The cultivated fruiting bodies are bright orange and are dried whole.
Sources: [2]
No major side effects are reported. Use caution with blood thinners (possible increased bleeding risk) and with blood-sugar-lowering drugs or insulin (cordyceps may lower blood glucose). Consult a doctor before use during pregnancy, breastfeeding or with existing conditions. Food supplements are not subject to approval: content and purity vary, and the label says little about how much actual fruiting body is inside.
No safety data are available. Without data, use is inadvisable.
Likewise no data for breastfeeding.
Not studied in children.
Drug interactions
Gerinnungshemmer und Thrombozytenhemmer
An increased bleeding risk in combination with blood thinners is described for cordyceps. Stop before surgery and mention it to your doctor.
Blutzuckersenkende Mittel (Insulin, orale Antidiabetika)
Cordyceps can lower blood sugar. Together with diabetes treatment, hypoglycaemia is possible.
Immunsuppressiva
The polysaccharides are credited with a stimulating effect on the immune system — which can run counter to a deliberate suppression.
Contraindications
- Upcoming surgery — stop in good time because of the possible bleeding risk.
- Ongoing immunosuppression, for example after a transplant.
- Known mould or spore allergy.
Harvested part: Fruiting body
- Time of day:
- Wild occurrences are rare and locally protected — when in doubt leave them standing and only photograph them. From one's own culture, harvest when the clubs are fully grown and their tips begin to swell but have not yet released spores.
- Drying:
- Dry whole fruiting bodies at no more than 45 °C. Cordycepin is heat-sensitive — higher temperatures cost exactly the compound in question.
- Storage:
- 12 months — Airtight, dark and cool. Light bleaches out the orange colour, which is a visible sign of storage that was too long or too bright.
- Cordycepin (3′-Desoxyadenosin)Other
The signature compound, closely resembling adenosine. Heat-sensitive, and its content differs considerably between fruiting body and mycelium.
- Polysaccharide und Beta-GlucanePolysaccharide
- AdenosinOther
- Carotinoide (Cordyxanthin)Other
The pigments that give the fungus its orange-red colour; they bleach out on exposure to light.
- Ergosterol (Provitamin D2)Other
- Mannitol (Cordycepinsäure)Other
- [1]MonographCordyceps — Memorial Sloan Kettering Cancer Center, Integrative Medicine(accessed: 2026-06-23)
- [2]MonographA brief review on the medicinal uses of Cordyceps militaris (ScienceDirect)(accessed: 2026-06-23)
- [3]MonographCordyceps militaris: An Overview of Its Chemical Constituents in Relation to Biological Activity (PMC8622900)(accessed: 2026-06-23)
- [4]CommonsFile:Cordyceps militaris - Scarlet Caterpillarclub fungus — Wikimedia Commons(accessed: 2026-06-23)