Cordyceps
Cordyceps is a genus of parasitic ascomycete fungi traditionally used in Tibetan and Chinese medicine. The two commercial supplement species are Cordyceps sinensis (now formally Ophiocordyceps sinensis — the wild Tibetan caterpillar fungus, very expensive) and Cordyceps militaris (cultivated, the source of most modern UK supplements). Marketed primarily for energy and exercise performance; the published human evidence is limited and EFSA has not authorised any UK health claim.
Camden Medicals editorial · Last reviewed 27 April 2026 · Next review April 2027
- Cross-checked against
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Camden's editorial team independently graded each health claim below on the strength of the published evidence — see the grade beside every condition.
- Class
- Mushroom
- Typical daily dose
- Most published trials use 1.0 to 4.0 g/day of Cordyceps militaris extract for 1 to 12 weeks.
- Top use evidence
- Limited
On this page
What it is
Cordyceps is a genus of around 400 ascomycete fungi that parasitise insects and other arthropods. Two species dominate the supplement market:
Cordyceps sinensis — formally reclassified as Ophiocordyceps sinensis in 2007. The wild "caterpillar fungus" found at high altitude in the Tibetan plateau, Bhutan, Nepal. Its parasitic life cycle on a ghost moth caterpillar is what gives it its name. Wild collection is environmentally and economically constrained; prices have risen to several thousand pounds per kilogram. Almost all "Cordyceps sinensis" sold in UK supplements is in fact a fermented mycelium cultured from the mushroom (Paecilomyces hepiali / Hirsutella sinensis) rather than the actual wild fungus.
Cordyceps militaris — a related species that fruits on insect hosts and can be cultivated commercially on grain or other substrates. It is the source of most modern Cordyceps supplements. The active compound profile differs from C. sinensis: notably, C. militaris is high in cordycepin (3'-deoxyadenosine) while wild C. sinensis is much lower.
At a glance
- A parasitic fungus genus; commercial supplements are usually Cordyceps militaris (cultivated) or wild Ophiocordyceps sinensis (rare and expensive).
- No GB-authorised health claim. EFSA evaluation of botanical health claims has been on hold since 2010.
- Most-trialled use: exercise performance / VO2 max in healthy and older adults — small benefit in some trials, mixed in others.
- Substrate matters: fruit body extract is what most studies used; mycelium-on-grain powder is largely grain by mass.
- Caution with anticoagulants and immunosuppressants. Talk to your pharmacist.
What people use it for
Recreational athletes interested in exercise-performance support
A handful of small RCTs suggest modest improvements in VO2 max and exercise-tolerance markers in both healthy younger adults and healthy older adults. Effect sizes are small and not consistently replicated. There is no GB-authorised health claim for exercise performance from cordyceps. [1,2]
Some evidenceLimitedPeople exploring traditional botanicals for general well-being
Long traditional-use history in Tibetan and Chinese medicine. Traditional-use framing is permissible in UK marketing; specific health claims are not authorised.
Some evidenceLimited
How it works
Cordyceps polysaccharides and the nucleoside cordycepin have been studied in cell-culture and animal models for energy metabolism, exercise performance, and immune effects. Translation to human clinical outcomes is limited; most published human trials are small and short-duration.
Common myths
Myth""Cordyceps sinensis" supplements contain wild Tibetan caterpillar fungus"
RealityAlmost never in UK retail. Wild C. sinensis (now Ophiocordyceps sinensis) is rare, expensive, and almost entirely consumed in the Asian luxury market. UK supplements labelled "Cordyceps sinensis" are typically a cultured mycelium of Paecilomyces hepiali — a related but distinct fungus that produces some of the same compounds.
Myth"Cordyceps "boosts ATP production" so it gives you more energy"
RealityThe "ATP production" framing comes from cell-culture studies of cordyceps polysaccharides and cordycepin. Translation to human muscle energy in everyday situations is not established by clinical trial evidence. The exercise-performance trials measured small VO2-max changes, not "more energy" in the consumer sense.
Myth"Cordyceps militaris is interchangeable with wild C. sinensis"
RealityThey are different species with different active compound profiles. C. militaris is high in cordycepin; wild C. sinensis is much lower. The published trials are mostly on C. militaris; labelling is often imprecise.
Common online questions
Synthesised from the questions UK shoppers most often ask online about Cordyceps. Each answer is editorial and links to its evidence in the Sources list below.
Will cordyceps improve my workouts?
Possibly modestly, in some people. A handful of small RCTs — in healthy younger adults and in healthy older adults — have shown small improvements in VO2-max or exercise-tolerance markers with Cordyceps supplementation over several weeks (a Cordyceps militaris blend at ~4 g/day, or Cordyceps sinensis Cs-4 at ~1 g/day). The effect is small and not always replicated. There is no GB-authorised health claim for exercise performance from cordyceps. [1,2]
Cordyceps sinensis vs Cordyceps militaris — what is the difference?
Different species. Wild C. sinensis (now Ophiocordyceps sinensis) is the rare and expensive Tibetan caterpillar fungus — almost never in UK retail supplements. C. militaris is cultivated commercially and is the source of most modern UK cordyceps. Active compound profiles differ — C. militaris is notably higher in cordycepin.
Is cordyceps safe in pregnancy?
There is not enough safety data on cordyceps supplementation in pregnancy. Talk to your midwife or GP first.
Can I take cordyceps with my asthma inhaler / blood pressure medication?
Talk to your pharmacist. Theoretical immune-modulation and platelet effects from animal data make conservative co-use the right default; the published interaction database is small.
Fruit body vs mycelium-on-grain — which should I buy?
Fruit body extract is what most published trials used. Mycelium on grain is largely grain by mass; bioactive content is lower. Look for "fruit body" explicitly and a stated cordycepin or beta-glucan percentage. Many products in UK retail are mycelium on grain without the fruit body.
🔬 Camden’s evidence review
The research Camden reviewed, graded on its strength. This is our own appraisal — it sits beneath the official guidance above, never above it.
Exercise performance / VO2 max in healthy adults
LimitedEvidencelimitedTwo small RCTs anchor the evidence. Hirsch 2016 (N=28 healthy young adults) found improved VO2-max and time-to-exhaustion after 3 weeks of a Cordyceps militaris-containing blend at 4 g/day. Chen 2010 (N=20 healthy adults aged 50-75) found a raised metabolic and ventilatory threshold — though no change in VO2-max — after 12 weeks of Cordyceps sinensis Cs-4 at 1 g/day. Effect sizes are small and results are mixed across the small published evidence base; the two trials used different Cordyceps species, doses and durations. [1,2]
Fatigue / energy in healthy adults
InsufficientEvidenceinsufficientAnecdotal and traditional-use claims; no convincing RCT evidence in healthy adults.
Renal / hepatic protection in clinical settings
InsufficientEvidenceinsufficientSmall early-stage trials in chronic kidney disease and hepatitis contexts; not standard of care in any UK guideline.
Safety
Cordyceps is generally well tolerated in published trials at typical doses, but long-term safety data in healthy adults is limited and EFSA has not authorised any UK health claim. Anticoagulant and immunosuppressant users should talk to a clinician first.
Talk to your pharmacist or GP first if you:
- You take an anticoagulant (warfarin, apixaban, rivaroxaban, etc.).
- You take immunosuppressants.
- You are pregnant, breastfeeding, or thinking of becoming pregnant.
- You have a known mushroom allergy.
- You are receiving cancer treatment.
Common side effects: Mild digestive complaints reported occasionally in trials.
Pregnancy and breastfeeding
Insufficient safety data in pregnancy. Talk to your midwife or GP.
Same framing.
Talk to your GP, midwife, or pharmacist before starting any supplement during pregnancy or breastfeeding.
More clinical detail (for clinicians and informed readers)
Contraindications
- Known mushroom allergy.
Drug interactions
- Anticoagulants — animal data on platelet effects; clinical interaction data limited.
- Immunosuppressants — theoretical immune-modulation.
This is not an exhaustive list. Always tell your prescriber and pharmacist about every supplement you take.
Common side effects
- Mild digestive complaints reported occasionally.
Rare side effects
- Allergic reactions in mushroom-allergic individuals.
How to take it
- Typical supplemental range
- Most published trials use 1.0 to 4.0 g/day of Cordyceps militaris extract for 1 to 12 weeks.
- Timing
- No specific timing requirement.
How to spot quality
Look for
- Species declared explicitly: Cordyceps militaris vs Ophiocordyceps sinensis (vs Paecilomyces hepiali for cultured-mycelium products labelled "C. sinensis").
- Substrate declared (fruit body vs mycelium-on-grain).
- Cordycepin percentage stated for C. militaris products (the most-studied bioactive).
- GMP-certified manufacture; ideally third-party heavy-metals testing.
Red flags
- Species not declared.
- Substrate not declared.
- Marketing claims about "boosting energy", "treating fatigue", "lowering cholesterol" beyond authorised claims.
Commonly combined with
Other ingredients that share a biological pathway, cofactor relationship, or evidence-backed protocol with this one. Mechanisms below cite primary physiology — not folk pairing. Doses are literature ranges, not recommendations. Talk to your pharmacist or GP before changing your stack, especially if you take prescription medication.
Lion's Mane
Limited evidenceCordyceps and Lion's Mane address different physiology and are commonly co-administered in cognitive-performance complexes.
Lion's Mane (Hericium erinaceus) acts on neurotrophic pathways via hericenones and erinacines stimulating NGF and BDNF. Cordyceps (most often the cultivated Cordyceps militaris in modern supplements) contains cordycepin, adenosine analogues and beta-glucans, with evidence for effects on mitochondrial ATP turnover, exercise tolerance and immune modulation in animal and small human studies. The combination targets different systems (neurotrophic vs energetic) without a published direct interaction; co-administration is rationalised by complementary system coverage rather than pharmacodynamic synergy.
Evidence: Lion's Mane evidence as above (Chong 2019; Samberkar 2015). Cordyceps human trials are limited and heterogeneous, with positive small studies in exercise tolerance and fatigue but no large definitive RCTs. No combination RCTs exist. [5,6]
Doses studied: Common product range: 500-1500 mg Lion's Mane + 500-1500 mg Cordyceps daily, in divided doses.
Reishi
Limited evidenceCordyceps and Reishi are both immunomodulatory beta-glucan mushrooms; commonly bundled in mushroom complexes covering immune + energy claims.
Both Cordyceps (most often C. militaris) and Reishi (Ganoderma lucidum) contain cell-wall beta-glucans that interact with pattern-recognition receptors (Dectin-1, TLR2/4) on innate immune cells. Cordyceps additionally contributes cordycepin and adenosine analogues with reported effects on exercise tolerance and mitochondrial function. The combination overlaps in immune mechanism rather than complementing it; the rationale for co-administration is mostly traditional Chinese medicine practice and product positioning (mushroom-complex SKUs).
Evidence: Xu 2011 (Am J Chin Med 39:15) reviews Reishi polysaccharide immunomodulation. Cordyceps human trials are limited. No RCTs evaluate the combination directly; combination rationale is mechanistic + traditional. [7]
Doses studied: Common product range: 500-1500 mg Cordyceps + 500-1000 mg Reishi (dual-extract preferred), divided across the day.