Cordyceps Benefits: What the Evidence Actually Shows
Published 13 min read
Cordyceps benefits graded by a nutritional therapist: what CS-4 and militaris trials show for energy and exercise, what failed, and who should avoid it.
Table of Contents
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Two trials put cordyceps in front of trained cyclists, and both found it did nothing for their endurance. That is the first thing you should know about cordyceps benefits: the best human evidence is small and mixed, one pilot in older adults improved a fitness marker, and the UK authorises no cordyceps health claim.
Cordyceps has limited human evidence: a small trial of the Cs-4 strain in healthy older adults found a better metabolic threshold, but two trials in trained cyclists found no effect on endurance, and Cordyceps militaris studies are small and inconsistent. Kidney and lung research comes from low-quality trials in patients, and no cordyceps health claim is authorised in the UK.
I graded every claim below by species, study type and population, keeping human trials apart from animal and cell work, using Cochrane reviews and PubMed abstracts checked in October 2026. I am a Nutritional Therapist (dipNT) who has run clinics at The Wellness Clinic at Harrods, and I would rather you know how thin a claim is than buy a bottle on a hunch. If you decide to try it anyway, our guide to the best mushroom supplements in the UK covers the buying side.
Editor's Note
I am a registered Nutritional Therapist and BANT member. Cordyceps is not a treatment for any disease.
Cordyceps Benefits at a Glance: The Evidence Grade for Each Claim
Here is the whole picture before the detail. Read the species column first, because it tells you whose results you are looking at.
| Claim | Species tested | Best evidence | Who was studied | Result | Grade |
|---|---|---|---|---|---|
| Aerobic fitness in older adults | Cs-4 | Chen 2010 pilot RCT | 20 healthy adults aged 50 to 75 | Metabolic threshold up 10.5%; VO2 max unchanged | Limited |
| Endurance in trained athletes | Cs-4 | Parcell 2004; Earnest 2004 | 22 trained and 17 amateur cyclists | No effect on any measure | Not Supported |
| High-intensity exercise tolerance | Militaris blend | Hirsch 2017 | 28 young adults | No effect at one week; VO2 max up after three weeks in the 10 who continued | Limited |
| Exercise performance overall | Militaris | Jedrejko 2026 review | 321 participants in five studies | "Findings were inconsistent" | Mixed |
| Immune markers | Militaris drink | Ontawong 2024 RCT | 40 healthy adults | NK cell activity rose; blood sugar unchanged | Limited |
| Kidney function | C. sinensis preparations | Cochrane 2014 | 1,746 people with chronic kidney disease | Lower creatinine alongside usual care; low-quality evidence | Patients Only |
| COPD | C. sinensis | Yu 2019 meta-analysis | 1,238 people with COPD | Potential benefits; no placebo-controlled trials | Patients Only |
| Blood sugar | Lab and animal work | MSKCC monograph | No human trial located | Preclinical; no change in Ontawong 2024 | Animal-Only |
| Ageing, libido and cancer | Lab and animal work | Traditional use and lab work | No human RCT located | No human result | Animal-Only |
No row earns a 'Strong' grade, and that tells you where the field stands.
An authorised health claim is a wording the regulator has approved for use on a label. The Great Britain nutrition and health claims register lists none for cordyceps, including the energy and stamina lines you will see on many UK product pages. A brand can describe what a study found, but it cannot tell you cordyceps works as fact, and neither will I.
CS-4 vs Militaris: Which Cordyceps Was Actually Studied
If you pick up a bottle labelled 'cordyceps', you are holding one of two different things, and the research does not transfer between them. Wild Ophiocordyceps sinensis grows on moth larvae, was renamed in 2007, and has a long record in traditional Chinese medicine for fatigue and coughs, according to Memorial Sloan Kettering Cancer Center.
The older exercise trials used a cultured preparation sold as Cordyceps sinensis Cs-4, under the name CordyMax. The newer trials, and most fruiting-body products you will find today, use Cordyceps militaris. Results from one cannot be borrowed for the other.
Militaris contains cordycepin, a bioactive compound described in a review of cordycepin. Bioactive means it does something in a lab, which is not the same as doing something for you. If a label leads with cordycepin, you are reading chemistry, not a trial result.
Then there is the question of whether your bottle holds what it says. A 2026 survey of 65 cordyceps products sold online, prompted by an outbreak of acute kidney injury linked to cordyceps products in Thailand, found 54.3% were falsified, and 6.2% were adulterated with corticosteroids. Some had militaris where the label said sinensis, and some lacked the labelled species altogether.
Energy and Exercise Performance: The Mixed Trial Record
If you want cordyceps for training, this is the evidence that matters, and it does not point one way. I train most mornings, with strength work and reformer Pilates, so I understand why a pre-workout shortcut is tempting. The trials are less tempting than the label.
Start with the encouraging one for you. Chen and colleagues gave 20 healthy adults aged 50 to 75 either Cs-4 (333 mg three times daily, about 1 g a day) or placebo for 12 weeks, in a pilot trial in the Journal of Alternative and Complementary Medicine.
Metabolic threshold rose 10.5% and ventilatory threshold 8.5%, but VO2 max did not change in either group. The authors called it a pilot, so you should treat it as a signal and not a result.
Now the two trials that found nothing, which you will rarely see on a product page. In a 2004 study by Parcell and colleagues, 22 endurance-trained male cyclists took 3 g a day of Cs-4 for five weeks, and their VO2peak, ventilatory threshold and time trial did not change.
A second 2004 trial by Earnest and colleagues gave 17 amateur cyclists a commercial formula containing Cs-4 plus rhodiola for 15 days. It found no effect on peak VO2, time to exhaustion or power.
The newer militaris evidence is thinner than the labels suggest. In a 2017 trial by Hirsch and colleagues, 28 young adults took 4 g a day of a mushroom blend containing militaris, and nothing differed from placebo at one week. After three weeks, VO2 max in the 10 who continued rose by 4.8 ml/kg/min against 0.9 on placebo, but a blend is not militaris alone, so you cannot credit the one ingredient.
A 2026 crossover trial by Farzan and Koushkie Jahromi gave 12 recreationally active young men 1 g of a standardised militaris extract, 30 minutes before maximal cycling. Their post-exercise reaction time was faster (964 against 1,034 ms), but peak VO2 was unchanged.
The 2026 Nutrients review of militaris pooled five studies and 321 participants aged 16 to 35. It called the findings "inconsistent" and named small samples, unstandardised preparations and multi-ingredient products as limits.
My plain summary for you: no consistent effect in trained athletes, only small signals in untrained or older people. I found no human trial showing that cordyceps raises ATP, a claim you may see in search summaries.
Immune Markers: One Small Militaris Trial
If immunity is your reason for looking, you have exactly one human trial to weigh, and it is small. In 2024, Ontawong and colleagues ran a randomised trial of a fermented militaris drink in healthy adults, with 10 men and 10 women per group, 40 people in total. The drink held 2.85 mg of cordycepin and was taken for eight weeks.
Natural killer cell activity rose in men from baseline at four weeks, and in women against placebo at eight weeks. Inflammatory markers fell within groups, IL-1 beta in men and IL-6 in women. Blood sugar, blood fats and safety markers did not differ from placebo, so you would not have seen a change there.
Here is how I would read it for you: a rise in a lab marker in 20 people on one drink is a reason to run a bigger trial, not a reason to expect fewer colds.
Kidney and Lung Health: Research in Patients, Not a Reason to Self-Treat
If you or someone you love has kidney or lung disease, read this section slowly, because the studies were done in patients and cannot be applied to you without your specialist. The largest source is a 2014 Cochrane review of Cordyceps sinensis in chronic kidney disease, covering 22 studies and 1,746 people. Used alongside conventional treatment, it was linked to lower serum creatinine, higher creatinine clearance and less protein in the urine.
The Cochrane authors then added the line that matters to you: "definitive conclusions could not be made because of the low quality of evidence". Risk of bias was high in four studies and unclear in 18. Memorial Sloan Kettering calls the evidence in transplant and haemodialysis patients "insufficient".
The lung data follow the same pattern, so you should read them the same way. A 2019 meta-analysis in stable COPD pooled 15 studies and 1,238 people, and reported potential benefits for lung function and quality of life. Its authors also noted that "No studies were placebo-controlled or of high methodological quality".
Please do not treat this as a case for self-treating. If you have kidney or lung disease, talk to your specialist before you take cordyceps, and never use it in place of prescribed care. The Thai product survey above was prompted by kidney injury, which is one more reason to be careful.
Blood Sugar, Libido, Ageing and Other Claims
If you have seen cordyceps linked with blood sugar, libido or anti-ageing, here is where those claims come from. Memorial Sloan Kettering describes the antidiabetic, antitumour and antiplatelet effects as preclinical, and says the clinical relevance of any blood sugar lowering is "yet to be determined". In the human trials above, the one militaris drink study found no change in blood sugar.
Libido, ageing and cancer claims rest on traditional use and on lab or animal work. I located no human randomised trial for any of them this month. The heart-health claim in search summaries leans on a 2019 mouse study, so you should not read it as a human result.
None of this means cordyceps does nothing for you. It means nobody has shown it yet.
Cordyceps Side Effects, Interactions and Who Should Avoid It
You deserve the safety picture stated plainly. In the trials, cordyceps was generally well tolerated, and Memorial Sloan Kettering states that "No major side effects have been reported". There are still real cautions you should know about.
Memorial Sloan Kettering reports a case of excessive bleeding after a tooth extraction in a person taking cordyceps daily. It may add to the effect of insulin and diabetes drugs, and it may increase the effect of warfarin and antiplatelet drugs. If you take any of those, please ask your pharmacist rather than guess.
Contamination is the other risk for you. A 1996 report from Taiwan described two people with lead poisoning from contaminated cordyceps powder, with up to 20,000 ppm of lead in the powder. Blood lead normalised once they stopped, and one needed chelation, which is why third-party testing matters to you.
Some people report that cordyceps made them jittery, sleepy or clumsy instead of energised, and Reddit threads are full of it. Those are anecdotes, so they cannot tell you how common it is, but they match what a stimulant-like effect would look like. If it happens to you, stop and speak to your GP.
Who Should Not Take Cordyceps Without Medical Advice
- You take insulin or diabetes medication, because it may add to the blood sugar effect.
- You take warfarin or antiplatelet drugs, because it may raise bleeding risk.
- You have surgery or dental work planned.
- You are pregnant or breastfeeding, because the data are lacking.
- You have kidney disease, and your specialist has not agreed.
If one of those applies to you, your GP or pharmacist is the right first call, not a supplement shelf. For the wider safety picture, my guide to mushroom supplement side effects covers what applies to most extracts.
How to Take Cordyceps: Trial Doses, Timing and Daily Use
You will not get a recommended dose from me, because no trial has set one for healthy adults. What I can give you is what the studies used. Chen used 333 mg of Cs-4 three times daily (about 1 g a day), Parcell used 3 g a day, Hirsch used 4 g a day of a blend, and Farzan used a single 1 g dose of militaris extract.
Across the militaris studies in the 2026 review, doses ranged from 1 to 12 g a day. Those are research doses of specific products, and the number on your bottle will use a different extract and different units. Nobody can convert one to the other with confidence, which is a good reason to ask your pharmacist.
How long it takes depends on which study you believe. Hirsch found nothing at one week and a signal at three, and Chen saw changes at 12 weeks. Farzan's single dose changed reaction time but not peak VO2.
Morning or night? No trial compared timing, and Farzan's 30 minutes before exercise is all anyone has tested. I found no human data on cycling cordyceps either, so you are free to choose what suits you. Our guide on how to take mushroom tinctures walks you through the practical side.
Choosing a Cordyceps Product: Species, Fruiting Body and Testing
If you still want to try it, that is a reasonable choice, and the aim is to avoid wasting money on a bottle that is not what it says. Use this checklist before you buy.
- Species named. The label should say militaris or sinensis. If it says only 'cordyceps', you cannot match it to any trial above.
- Fruiting body or mycelium. Fruiting body is the mushroom itself; mycelium grown on grain can carry a lot of grain with it. Ask how much of the powder is mushroom.
- Extraction method. A dual extraction uses water and alcohol, so it captures compounds either one would miss; our explainer on dual extraction goes further.
- Stated content. Look for a stated cordycepin or beta-glucan figure, not just a milligram count of 'extract'.
- Third-party testing. Ask for heavy metal results, given the lead cases and the 2026 survey.
Balance Journal's founder, James Bellis, also founded Balance Coffee, which sells a cordyceps elixir. A 3:1 dual extract made from 100% fruiting body and listed as third-party tested is one example of that format: the Cordyceps Elixir, a 50 ml glass bottle from £39.99. Its product page does not name the species, so I cannot tell you which trials apply to it, and you should ask before you buy.
If you want to compare formats, the best mushroom tincture roundup covers tinctures, a mushroom powder is the other common route, and the best mushroom supplements in the UK guide ranks the field. A ranked best cordyceps supplement guide is not written yet, and a guide to mushroom tincture benefits is planned.
Last, you may be weighing lion's mane against cordyceps. Cordyceps is studied mainly for exercise capacity and lion's mane mainly for cognition, and lion's mane benefits sets that evidence out in the same graded way. The third species guide, reishi benefits, follows soon.
You do not need a cupboard of mushrooms to feel well. Sleep, food and training will do more for your energy than any bottle, and trying cordyceps is optional.
Studies Cited
Every study named above, so you can check my reading against the source.
- Chen S et al. J Altern Complement Med 2010;16(5):585-90.
- Parcell AC et al. Int J Sport Nutr Exerc Metab 2004;14(2):236-42.
- Earnest CP et al. Med Sci Sports Exerc 2004;36(3):504-9.
- Hirsch KR et al. J Diet Suppl 2017;14(1):42-53.
- Farzan H, Koushkie Jahromi M. PLoS One 2026;21(7):e0351725.
- Jedrejko M et al. Nutrients 2026;18(5):781.
- Ontawong A et al. Sci Rep 2024;14(1):7994.
- Zhang HW et al. Cochrane Database Syst Rev 2014;(12):CD008353.
- Yu X et al. Evid Based Complement Alternat Med 2019:4903671.
- Wu TN et al. Sci Total Environ 1996;182(1-3):193-5.
- Wirasathien L et al. BMC Complement Med Ther 2026;26(1):184.
- Cordycepin for health and wellbeing, a review of a bioactive metabolite of Cordyceps.
- Memorial Sloan Kettering Cancer Center, cordyceps monograph, last updated 10 February 2022.
- Great Britain nutrition and health claims register, gov.uk.
This article is for information and is not medical advice. Speak to your GP or pharmacist before taking cordyceps, especially if you take medication.
Frequently Asked Questions
What does taking cordyceps do to your body?
Human evidence is small and mixed. A pilot of the Cs-4 strain improved a fitness threshold in older adults, but two trials in trained cyclists found no endurance benefit, and militaris studies are inconsistent. Kidney and lung research comes from patients in low-quality trials, and no cordyceps health claim is authorised in the UK.
Is it safe to take cordyceps every day?
Trials gave cordyceps daily for between one and 16 weeks and reported it as well tolerated. Long-term data are thin, so nobody can say what years of daily use does, and contamination and falsified products are the bigger practical risks. If you take medication, check with your GP or pharmacist first.
Which is better, lion's mane or cordyceps?
Neither wins overall, because they have different evidence bases. Lion's mane is studied mainly for cognition and cordyceps mainly for exercise capacity, and neither has a UK-authorised health claim. Read our lion's mane benefits guide, then choose based on the question you want answered.
What not to mix with cordyceps?
Memorial Sloan Kettering advises caution with insulin and diabetes drugs, because cordyceps may add to their blood sugar effect, and with warfarin and antiplatelet drugs, because it may increase bleeding. Ask your GP or pharmacist before combining it with either. Mention it to your surgical or dental team before any procedure.
Who should avoid cordyceps?
Avoid it without medical advice if you take blood thinners or diabetes medication, have surgery or dental work planned, or are pregnant or breastfeeding, because the data are lacking. If you have kidney disease, speak to your specialist first. Cordyceps is never a substitute for prescribed care.
How long does it take for cordyceps to kick in?
No trial gives a firm answer. Hirsch 2017 found no effect at one week and a signal at three weeks, Chen 2010 saw changes at 12 weeks, and a single 1 g dose of militaris in Farzan 2026 changed reaction time but not peak VO2. You should not expect a noticeable effect in days.
Are there cordyceps benefits for men?
No benefit specific to men has been proven. Libido claims rest on traditional use and animal work, and I found no human randomised trial. Most exercise trials enrolled men with mixed results, so if libido is your concern, a GP can look for causes a supplement would not address.
Are there cordyceps benefits for women?
No women-specific benefit has been shown. The 2024 militaris trial found natural killer cell activity rose in women at eight weeks, but it had only 10 women per group, which is too small to rely on. Cordyceps is not advised in pregnancy or breastfeeding, because the data are lacking.
A registered Nutritional Therapist and member of BANT, Clemmie blends science with a holistic approach to wellbeing.
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