Cordyceps: what it is, what it helps with, and how to dose the mushroom for energy and endurance

Tibetan herders observed centuries ago that goats grazing in areas covered with a strange orange fungus were exceptionally strong and lively. Thus began the story of cordyceps – a fungus that today is included in the supplementation of athletes worldwide. A clinical study by Hirsch et al. (Journal of Dietary Supplements, 2017) showed that three weeks of cordyceps supplementation increased VO2max in active adults by 7%. How is this possible and which species should you choose? This article explains the mechanisms of action, the differences between Cordyceps militaris and sinensis, dosing, and practical applications – separately for athletes and for those struggling with fatigue in everyday life.

KEY INFORMATION
• The study by Hirsch et al. (Journal of Dietary Supplements, 2017) confirmed a 7% increase in VO2max after 3 weeks of supplementation with 3 g/d of cordyceps in active adults (n=28).
• Laboratory-grown Cordyceps militaris contains a higher concentration of cordycepin than the rare and expensive Cordyceps sinensis – with comparable biological activity.
• Recommended dosage of the extract: 1–3 g/d; first effects after 2–3 weeks of regular use.
• Cordyceps acts as both an adaptogen and an ergogenic aid – it reduces perceived fatigue and improves ATP production in mitochondria.

What is cordyceps and where does it come from?

Cordyceps is a genus of fungi from the class Sordariomycetes, primarily known for two species: Cordyceps sinensis (now reclassified as Ophiocordyceps sinensis) and Cordyceps militaris. In nature, cordyceps sinensis parasitizes the larvae of moths in the high Himalayas (3500–5000 m above sea level) – it overwinters in the larva's body, and in spring, it pushes orange fruiting bodies out of the ground. This extraordinary biology has made it available only to the wealthy for centuries: 1 kg of wild raw material today costs between 10,000 and 20,000 USD.

A breakthrough for the mass availability of cordyceps was the ability to cultivate laboratory-grown Cordyceps militaris on grain substrates. C. militaris contains a higher concentration of cordycepin (a key adenosine analogue) than wild sinensis, is cultivated under controlled conditions without heavy metals and environmental pollutants, and its price is a fraction of the cost of wild raw material. Most products available on the market and clinical studies conducted after 2010 pertain specifically to C. militaris.

History of use: traditional Tibetan and Chinese medicine (yartsa gunbu – "winter grass, summer worm") has utilized cordyceps for over 1500 years as a vitality enhancer, improving sexual function and lung health. The first mention in medical literature comes from the 17th-century treatise Ben Cao Bei Yao. Cordyceps reached Western science after 1993, when Chinese runners at the World Championships in Stuttgart broke several world records – their coach admitted they were using cordyceps supplementation.

How cordyceps affects energy – the ATP and mitochondria mechanism

The central action of cordyceps on energy occurs through three interconnected mechanisms that together improve the energy efficiency of muscle cells and reduce metabolic fatigue.

Cordycepin and ATP production: Cordycepin (3′-deoxyadenosine) is an adenosine analogue – one of the key building blocks of ATP (adenosine triphosphate, the "energy currency" of cells). Studies by Tuli et al. (3 Biotech, 2014) showed that cordycepin activates AMPK (AMP-activated protein kinase) – an enzyme that regulates energy metabolism in muscles, stimulating mitochondria to increase ATP synthesis. The effect: muscle cells produce more energy with the same oxygen consumption.

Adenosine and vasodilation: The adenosine found in cordyceps acts as a vasodilator – it expands blood vessels, improving blood flow and oxygen delivery to working muscles. This mechanism is similar to that of beetroot (nitrate → nitric oxide), but through a different biochemical pathway. Better muscle perfusion = more oxygen = higher aerobic endurance.

β-glucans and mitochondrial efficiency: The polysaccharides in cordyceps exhibit mitoprotective effects – protecting mitochondria from oxidative stress during intense exertion. In vitro studies reduce ROS (reactive oxygen species) production in muscle mitochondria by 20–35%, which directly translates to slower onset of muscle fatigue.

Our observations: The subjective effects of cordyceps differ from those of caffeine or guarana. Caffeine provides a "kick" felt after 30–60 minutes and a similarly pronounced crash. Cordyceps acts more gently and broadly – after 2–3 weeks of regular use, we notice a clearer difference in the "overall battery level" than in one-time energy spikes. It's more like raising the baseline energy level than stimulation.

Cordyceps militaris vs Cordyceps sinensis – which one to choose?

This is one of the most common questions when purchasing cordyceps, and the answer is quite clear today: for most applications, Cordyceps militaris is the better choice.

Hirsch et al. (Journal of Dietary Supplements, 2017) – one of the few double-blind RCTs with cordyceps – confirmed that a standardized extract of C. militaris (3 g/d for 3 weeks) increased VO2max by 7% in active adults compared to placebo. The study included 28 participants, used an exercise protocol on an ergometer, and measured aerobic capacity objectively. There are significantly fewer comparable studies with C. sinensis, and the methodology is usually weaker.

Differences between species: C. militaris contains a higher concentration of cordycepin (up to 0.5–2% in dry mass vs 0.01–0.3% in wild sinensis), which is crucial because cordycepin is the main biologically active molecule responsible for energy effects. C. sinensis has a more diverse polysaccharide profile, but its wild form is susceptible to heavy metal contamination from Himalayan soils.

When purchasing, look for products with: declared β-glucan content above 25%, species designation (C. militaris preferred), extract 4:1 or higher (not raw fruiting body powder), absence of fillers, and a purity certificate from an independent laboratory.

Cordyceps and sports endurance – what do studies say?

Aside from the Hirsch et al. study, the scientific literature on cordyceps and physical exertion includes several other valuable works. Chen et al. (Journal of Alternative and Complementary Medicine, 2010) in a study with 20 older adults (ages 50–75), they found that CS-4 (standardized polysaccharide fraction of cordyceps) 3 g/d for 12 weeks increased exercise capacity measured by time to exhaustion on an ergometer by 10.5% and reduced blood lactate levels after exertion by 18%.

The reduction of lactate is particularly interesting for athletes working at intensities close to the anaerobic threshold. Less lactate = slower onset of muscle acidosis = higher possible intensity over longer work periods. Mechanism: cordyceps improves lactate clearance by stimulating lactate dehydrogenase (LDH) and enhancing muscle perfusion.

Who benefits most from cordyceps: data suggests that effects are more pronounced in older individuals (50+), those in poor baseline condition, and endurance athletes (running, cycling, triathlon). In elite athletes with high baseline VO2max, the effects may be marginally smaller – the level of physiological assessment is a significant moderator.

Cordyceps as an adaptogen – fatigue, stress, and sleep

Beyond its ergogenic effects, cordyceps exhibits classic adaptogenic properties: it helps the body cope with various types of stressors (physical and mental) without causing excessive stimulation. This distinguishes it from stimulants – it neither speeds up nor slows down distinctly, but normalizes the stress response.

In the context of physiological fatigue (not just athletic): cordyceps shows anti-fatigue effects by modulating the HPA axis and influencing adrenal function. Zhao et al. (Chinese Journal of Integrative Medicine, 2004) demonstrated that polysaccharides from C. sinensis (CS-4) reduced subjective feelings of fatigue in patients with chronic fatigue by 28% after 8 weeks of use at a dose of 3 g/d.

Effects on libido and sexual functions: cordyceps is traditionally used as a "mountain aphrodisiac." Adenosine and cordycepin may improve blood flow and sexual function. Animal studies confirm increased testosterone and improved sexual function, although there are few clinical studies in humans. Effects on libido reported by users after 4–6 weeks may partly result from overall energy improvement and fatigue reduction, rather than direct hormonal action.

On lung functions: traditionally, cordyceps has been used for "lung deficiency" (cough, asthma, difficulty breathing during exertion). Adenosine and cordycepin have bronchodilatory effects. Several studies in COPD patients have shown improvement in spirometric parameters with cordyceps supplementation.

How to dose cordyceps – a practical guide

Dosing cordyceps depends on the form of the supplement, the purpose of use, and the baseline health condition. A few clear guidelines eliminate most mistakes made by those starting supplementation.

Standardized extract (4:1 or 8:1): The recommended dose is 1–3 g/d (1000–3000 mg). Clinical studies by Hirsch et al. and Chen et al. used a dose of 3 g/d, which is the upper limit of the therapeutic range. Start with 1 g/d for the first 2 weeks to assess tolerance, then increase to 2–3 g/d. The extract is the form with the best clinical evidence and the highest bioavailability of active ingredients.

Raw fruiting body powder (unextracted): Requires doses of 4–6 g/d due to lower bioavailability. Chitin in the cell walls of the fungus limits the absorption of polysaccharides and cordycepin without an extraction process. The powder is cheaper but not economical per mg of active ingredient.

Timing: For energy and sports purposes – in the morning on an empty stomach or 60–90 minutes before training. For adaptogenic purposes (overall fatigue reduction) – splitting into 2 equal doses in the morning and at noon provides a more stable effect throughout the day. Cordyceps does not contain caffeine, so it does not disrupt sleep when taken later.

Usage cycle: Ideally 8–12 weeks of regular use, followed by a 4-week break. There is no safety data for use beyond 12 months without interruption.

Cordyceps and immunity and oxidative stress

In addition to its ergogenic effects, cordyceps exhibits strong immunomodulatory and antioxidant properties, which are significant for individuals exposed to physical stress and chronic fatigue. Panda and Swain (Journal of Ethnopharmacology, 2011) In a systematic review of 30 in vitro and in vivo studies, they indicated that cordyceps polysaccharides activate macrophages, NK lymphocytes, and the production of interferon-γ – mechanisms crucial for innate immunity.

From an athlete's perspective: intense training generates oxidative stress through the production of ROS (reactive oxygen species). Cordyceps contains powerful antioxidants – ergosterol, cordycepin, and β-glucans – that neutralize ROS and accelerate recovery. This is one of the reasons why many people combine cordyceps with a high-protein diet and a recovery training plan: reduced post-exercise inflammation translates to a faster return to form.

Cordyceps also exhibits anticancer activity in vitro – cordycepin inhibits the proliferation of cancer cells by inhibiting RNA synthesis and inducing apoptosis in cell lines. However, these are preclinical results and do not provide a basis for using cordyceps as an oncological drug. Their significance lies in confirming the broad biological profile of cordycepin.

For individuals with chronic fatigue and weakened immunity (frequent infections, long recovery times), cordyceps can be a valuable addition to basic supplements. The combination of energizing and immunomodulating effects makes it particularly valuable in autumn and winter when the body is exposed to seasonal infections and a lack of sunlight that lowers natural immunity.

Interactions and safety – who should exercise caution?

Cordyceps is generally safe for healthy adults at recommended doses of 1–3 g/day. Known interactions and risk groups require attention before starting supplementation.

Anticoagulant medications (warfarin, clopidogrel, aspirin): Cordycepin exhibits platelet aggregation inhibition similar to adenosine. With blood-thinning medications, it may enhance the anticoagulant effect and increase the risk of bleeding. A medical consultation and monitoring of INR are absolutely necessary.

Autoimmune diseases and immunosuppressive medications: The immunostimulatory effect of cordyceps may interfere with immunosuppressive therapy (post-transplant, in SLE, RA, MS). In these conditions, use requires consultation with the treating specialist.

Diabetes and hypoglycemic medications: Cordyceps may slightly lower blood glucose levels. With insulin or metformin, monitoring of glycemia is necessary.

Adverse effects when exceeding recommended doses (above 5 g/day): gastrointestinal discomfort (nausea, loose stools), dry mouth, mild dizziness. These resolve after reducing the dose. In individuals allergic to fungi, allergic reactions may occur.

Also, read our article on adaptogenic mushrooms.

Frequently Asked Questions

What is cordyceps and why is it called the energy mushroom?

Cordyceps is a medicinal mushroom traditionally used in Tibetan and Chinese medicine for over 1500 years. It is known as the "energy mushroom" due to its adenosine-derived components (cordycepin, adenosine) that stimulate ATP production in mitochondria, leading to measurable improvements in physical endurance and reduced fatigue.

What is the difference between Cordyceps militaris and Cordyceps sinensis?

Cordyceps sinensis (wild, Himalayan) is extremely rare and expensive – 1 kg of raw material can cost up to 20,000 USD. Cordyceps militaris is cultivated in laboratories, contains a higher concentration of cordycepin, and is comparably effective at a fraction of the price. Studies by Hirsch et al. (2017) confirmed similar biological activity between the two species.

How does cordyceps affect VO2max and endurance?

The study by Hirsch et al. (Journal of Dietary Supplements, 2017) involving 28 active adults showed that supplementation with cordyceps at 3 g/day for 3 weeks increased VO2max by 7% compared to placebo. Cordycepin and adenosine stimulate ATP synthesis in muscle mitochondria and improve oxygen utilization efficiency during exercise.

What is the recommended dosage of cordyceps?

The recommended dosage of standardized cordyceps extract is 1–3 g/day (1000–3000 mg). Clinical studies most commonly used a dose of 3 g/day of a 4:1 or 8:1 extract. The first effects on energy and endurance appear after 2–3 weeks of regular use, with full adaptogenic effects after 8–12 weeks.

Is cordyceps safe for everyone?

Cordyceps is well tolerated by healthy adults. Cordycepin exhibits anticoagulant properties – a medical consultation is necessary when taking blood-thinning medications (warfarin, clopidogrel). Individuals with autoimmune diseases or on immunosuppressants should seek medical advice before starting supplementation.

When is the best time to take cordyceps – in the morning or before a workout?

Cordyceps is best taken in the morning or 60–90 minutes before a workout. It does not contain caffeine, so it does not interfere with sleep when taken in the evening. For adaptogenic purposes (reducing overall fatigue), dividing the dose into two in the morning and at noon provides a more stable effect throughout the day.

Can cordyceps be combined with coffee or other adaptogens?

Yes – cordyceps pairs excellently with coffee (synergistic energizing effect without excessive stimulation) and with other functional mushrooms: lion's mane (focus and energy), reishi (energy and immunity). The cordyceps and ashwagandha stack combines endurance enhancement with post-exercise cortisol modulation.

This article is for informational and educational purposes and does not replace consultation with a doctor. If you are pregnant, breastfeeding, taking medications, or have chronic conditions, consult the use of supplements or herbs with a specialist.

Author: Michał Waluk · Published: 2026-05-04 · Updated: 2026-05-04