What Does Cordyceps Mushroom Do To You? Exploring Benefits and Side Effects

December 28, 2025 •

3 min read

For centuries, the cordyceps mushroom has been a cornerstone of Traditional Chinese Medicine, prized for its ability to restore health, boost vitality, and support lung function. While historically harvested from parasitic fungi found on insect larvae, modern supplements often use lab-grown variants like Cordyceps militaris.

Quick Summary

Cordyceps is a fungus with adaptogenic properties that may enhance athletic performance, boost energy levels, and modulate the immune system, though potential side effects exist.

Key Points

Enhances Athletic Performance: Cordyceps may boost energy levels, improve oxygen utilization (VO2 max), and speed up recovery by increasing ATP production.
Modulates the Immune System: It functions as an immunomodulator, capable of both boosting and suppressing immune activity by influencing key immune cells and acting as an antioxidant.
Offers Adaptogenic Support: Cordyceps helps the body manage physical and mental stress, which can lead to reduced fatigue and increased overall vitality.
Provides Other Health Benefits: Traditional and preliminary research suggests potential benefits for anti-aging, as well as kidney, liver, and cardiovascular health.
Carries Safety Considerations: Common side effects are typically mild digestive issues. People with autoimmune diseases, bleeding disorders, or on specific medications should use caution or avoid it.
Modern Supplements are Cultivated: Due to the rarity and cost of wild Cordyceps sinensis, most commercial supplements use the more accessible and equally effective lab-grown Cordyceps militaris.

How Cordyceps Interacts with the Body

Cordyceps contains several bioactive compounds, including polysaccharides, adenosine, and the powerful cordycepin, that contribute to its effects.

Cellular Energy Production: The fungus is believed to increase the production of adenosine triphosphate (ATP), the body's primary energy molecule. Higher ATP levels can provide more energy to muscles during exercise, delaying fatigue.
Oxygen Utilization: Cordyceps may improve the body's use of oxygen, which is a critical factor for endurance and stamina. This is often measured by VO2 max, with some studies showing improvement after supplementation.
Adaptogenic Effects: As an adaptogen, cordyceps helps the body better respond to physical and mental stress. By regulating stress hormones, it can reduce fatigue and improve overall vitality.
Immune System Modulation: Rather than simply boosting the immune system, cordyceps has a bidirectional, or modulating, effect. It can either stimulate or suppress immune responses by regulating different immune cells like macrophages, T-cells, and natural killer cells.

Key Benefits of Taking Cordyceps

Improved Athletic Performance

One of the most well-known applications for cordyceps is enhancing athletic performance. The combination of increased ATP production and improved oxygen delivery can lead to noticeable gains.

Improved aerobic capacity and VO2 max
Increased stamina and endurance
Quicker recovery times after intense exercise
Reduced muscle soreness and inflammation

Supporting Immune Function

Cordyceps' ability to modulate the immune system makes it a promising supplement for overall health. Its anti-inflammatory and antioxidant properties protect cells from damage, while specific compounds can activate immune defenses.

Other Health Advantages

Beyond performance and immunity, cordyceps has been traditionally used for a range of other conditions:

Anti-Aging Properties: The antioxidants in cordyceps help neutralize free radicals that cause cellular damage, potentially supporting healthy aging.
Kidney and Liver Health: In Traditional Chinese Medicine, cordyceps is used to support kidney and liver function and protect these organs from oxidative stress.
Cardiovascular Support: By improving circulation and potentially impacting cholesterol and blood pressure, cordyceps may promote cardiovascular wellness.

Possible Side Effects and Who Should Be Cautious

While generally considered safe for most people, some individuals may experience side effects, particularly with high doses or due to pre-existing conditions.

Reported Side Effects

Mild gastrointestinal issues like nausea, diarrhea, or upset stomach
Dry mouth
Bloating
In rare cases, allergic reactions like a rash or hives

Contraindications and Cautions

Autoimmune Diseases: As cordyceps can activate the immune system, people with autoimmune conditions such as lupus (SLE), rheumatoid arthritis (RA), or multiple sclerosis (MS) should avoid it, as it could worsen symptoms.
Blood Thinners: Cordyceps may slow blood clotting. Individuals on anticoagulant or antiplatelet medications should consult a doctor due to an increased risk of bleeding.
Upcoming Surgery: For the same reason, those with scheduled surgeries should stop taking cordyceps at least two weeks prior.
Pregnancy and Breastfeeding: There is insufficient evidence to confirm safety for these groups, so it is best to avoid use.
Diabetes Medication: Combining cordyceps with diabetes medication might cause blood sugar to drop too low, necessitating medical supervision.

Comparison of Cordyceps Species


Feature	Cordyceps sinensis (Wild)	Cordyceps militaris (Cultivated)
Origin	Grows naturally on ghost moth larvae in high-altitude regions.	Cultivated in labs using a base like rice, making it widely available.
Rarity	Extremely rare and expensive due to over-harvesting.	Widely accessible and more affordable.
Active Compounds	Contains polysaccharides, cordycepin, and other compounds.	Shares similar active compounds, with studies showing comparable or superior effects to wild C. sinensis.
Supplementation	Most supplements labeled C. sinensis are actually lab-grown mycelium due to cost and rarity.	A common and reliable source for modern cordyceps supplements.

Conclusion

Cordyceps is a fascinating medicinal fungus with a long history of use and a growing body of modern research supporting its therapeutic potential. Its effects on energy, athletic performance, and immune health are particularly noteworthy due to the bioactive compounds that influence cellular function. While it is generally well-tolerated, awareness of potential side effects and contraindications, especially for individuals with autoimmune conditions, bleeding disorders, or those on specific medications, is crucial. Ultimately, for most healthy individuals, cordyceps can be a beneficial addition to a wellness routine, but it is not a substitute for proper medical care or a healthy lifestyle. For more scientific insights, consult authoritative resources such as the National Center for Biotechnology Information (NCBI).

Frequently Asked Questions

The primary function of cordyceps for humans is its adaptogenic effect, which helps the body manage stress and fatigue, alongside its capacity to enhance energy, boost athletic performance, and modulate immune responses.

Yes, cordyceps is known for its energy-boosting properties and its ability to combat fatigue. It works by potentially increasing the body's production of ATP, the molecule used for cellular energy.

Yes, cordyceps acts as an immunomodulator, meaning it can regulate or balance the immune system. It can enhance the activity of certain immune cells while also possessing anti-inflammatory properties.

Common side effects are typically mild and can include gastrointestinal issues such as nausea, upset stomach, or diarrhea. For most people, cordyceps is well-tolerated.

Individuals with autoimmune diseases (like MS or lupus), those on immunosuppressant drugs, people with bleeding disorders, or those awaiting surgery should avoid cordyceps due to its effects on the immune system and blood clotting.

No, the fictional 'zombie fungus' depicted in shows like The Last of Us is a mutated variant. The high body temperature of humans is sufficient to prevent infection, and the type of cordyceps used in supplements is safe and cultivated in labs.

The effects of cordyceps often build over time rather than providing an immediate stimulant effect. Many studies showing significant results used consistent supplementation over several weeks, with some benefits appearing after just a week.