Can Cordyceps Infect Humans? The Real Fungus Explained

No, cordyceps cannot infect humans. Cordyceps and its relatives are fungi that infect insects and other arthropods, and each species is adapted to its own hosts. Human body heat and the immune system keep out most fungi, and cordyceps is not among the fungi known to cause disease in people. The "zombie ant fungus" from nature documentaries is a related fungus called Ophiocordyceps, and the cordyceps in supplements is a cultivated fungus grown on grains or insects. This guide explains what cordyceps is, what it really does to ants, why people are out of its reach, and what is worth knowing about cordyceps supplements.

It is educational, not medical advice.

Key Takeaways

• Cordyceps is a group of insect fungi. The old genus held over 400 species that infect arthropods; in 2007 it was split, and the zombie ant fungus now sits in a separate genus, Ophiocordyceps (Sung et al., 2007).
• The zombie ant story is real, but it is about ants. Infected carpenter ants leave their nests, bite into a leaf vein and die there, where the fungus can grow and spread (Hughes et al., 2011).
• Your body is too warm for most fungi. In a test of 4,802 fungal strains, most could not grow at mammal body temperature (Robert and Casadevall, 2009).
• Cordyceps is not on the list of fungi that threaten people. The World Health Organization list of the 19 fungi that pose the greatest risk to public health does not include it (World Health Organization, 2022).
• Cordyceps supplements are a different question. They are grown fungus, dried and extracted, and they are generally well tolerated (LiverTox: Cordyceps).

What Is Cordyceps?

Cordyceps is a name for fungi that live as parasites of insects and other arthropods. When scientists sorted the group by DNA in 2007, the old genus Cordyceps, with over 400 species, turned out to be several different branches of the fungal family tree. Cordyceps militaris became the reference species for the genus Cordyceps, while many dark, wiry species, including the zombie ant fungus and the Himalayan caterpillar fungus, moved to a new genus, Ophiocordyceps (Sung et al., 2007).

Most people still use "cordyceps" for all of them, which is why a search for cordyceps can turn up both ant videos and supplement labels. They are related fungi, not the same organism.

The Zombie Ant Fungus: What Cordyceps Does to Ants

The famous behavior comes from Ophiocordyceps unilateralis and its close relatives. In a study in a Thai rainforest, researchers followed carpenter ants infected with the fungus (Hughes et al., 2011):

• Infected ants leave the canopy where they nest and come down to young plants near the forest floor.
• They wander and convulse, walking at random and falling, which keeps them from climbing back up.
• They lock onto a leaf. Around solar noon, ants bite into a vein on the underside of a leaf, about 25 cm (10 inches) above the soil. The jaw muscles waste away so the bite holds after death.
• The fungus fills the head. Large numbers of fungal cells were found inside the heads of dying ants, likely behind the muscle changes.

The spot is not random: ants died in "graveyards" where the conditions suit the fungus as it grows out of the body and spreads to new ants. It is one of the clearest examples of a parasite steering its host, and it is entirely an insect story.

Can Cordyceps Infect Humans?

No. Three things stand in the way.

• Body heat. People keep a core temperature of about 37 °C (98.6 °F). When researchers tested 4,802 fungal strains from 144 groups, most could not grow at mammal temperatures, and each 1 °C rise between 30 °C and 40 °C ruled out about 6% more of them. The authors describe warm-bloodedness as a strong, built-in defense against fungi (Robert and Casadevall, 2009). Cordyceps militaris, for comparison, is grown into mushrooms at 15 to 25 °C (59 to 77 °F) in cultivation studies (Shao et al., 2026).
• The immune system. Mammals combine high body temperature with a complex immune system, and that pairing is why relatively few fungi cause disease in mammals compared with insects, amphibians and plants (Garcia-Solache and Casadevall, 2010).
• Host specialization. Cordyceps species are adapted to particular insects and other arthropods (Sung et al., 2007). The zombie ant fungus is tuned to the behavior and body of its ant hosts (Hughes et al., 2011), and people are far outside that range.

The fungi that do cause serious disease in people are a short, specific list. In 2022 the World Health Organization published the 19 fungi it considers the greatest threat to public health, and none of them is a cordyceps or Ophiocordyceps species (World Health Organization, 2022).

Is Cordyceps a Virus?

No. Cordyceps is a fungus, a relative of yeasts and molds, not a virus. Searches for a "cordyceps virus" or a "cordyceps brain infection" mostly come from fiction: the video game and TV series The Last of Us imagine a cordyceps that has learned to infect people. The show borrows the real zombie ant behavior and applies it to humans. That jump is the fictional part.

Could Cordyceps Evolve to Infect Humans?

This is the question behind most "cordyceps dangers" searches. Researchers who study fungi and body heat have proposed that a warming climate could, over time, favor fungi that tolerate higher temperatures, and that this could bring new fungal diseases to mammals (Garcia-Solache and Casadevall, 2010). That idea is about fungi in general.

For cordyceps, the gap is wide. A species would need to grow at human body temperature, get past a mammal immune system, and complete its life cycle in a host that is nothing like the insects it is built for. Cordyceps species are specialists that depend on particular arthropod hosts (Sung et al., 2007, Hughes et al., 2011).

Cordyceps Dangers: Are Cordyceps Supplements Safe?

The cordyceps sold as a supplement is grown on purpose. Cordyceps militaris is cultivated on grains, insects or other materials, then dried and extracted (Park, 2025). Ophiocordyceps sinensis grows wild on its insect host, a Thitarodes moth (Yan et al., 2026), and is so scarce that it is mostly produced as mycelium grown in tanks instead (He et al., 2025).

Cordyceps supplements are generally well tolerated. Reported side effects are mild, such as stomach discomfort, loose stools, dry mouth, nausea or rash, and LiverTox rates cordyceps an unlikely cause of liver injury (LiverTox: Cordyceps).

Talk with your clinician first if you:

• take blood thinners, since cordyceps may add to bleeding risk;
• take blood sugar medication, since cordyceps may lower blood sugar;
• take immune-suppressing medication;
• are pregnant or breastfeeding, since not enough is known; avoid it unless your clinician agrees.

For choosing a product, see our guide to the best cordyceps supplement, and for the two main species, cordyceps militaris benefits and uses.

Cordyceps Militaris vs Ophiocordyceps Sinensis vs the Zombie Ant Fungus

Fungus	Natural host	Where it is known from	Used in supplements?
Cordyceps militaris	Insects	Wild in many regions; cultivated on grains and insects	Yes, the main species in cordyceps supplements
Ophiocordyceps sinensis	Thitarodes moth larvae	High Himalayas and the Tibetan Plateau	Yes, mostly as tank-grown mycelium
Ophiocordyceps unilateralis (zombie ant fungus)	Carpenter ants	Tropical forests	No

Sources: Sung et al., 2007, Park, 2025, Yan et al., 2026, He et al., 2025, Hughes et al., 2011.

Where Forage Fits

Our Forage capsules include 200 mg of an 8:1 cordyceps fruiting body extract per two-capsule serving, alongside 8:1 fruiting body extracts of lion’s mane (200 mg), reishi (200 mg), chaga, maitake, turkey tail and shiitake (150 mg each), plus 100 mg of Himalayan shilajit, 100 mg of ashwagandha root extract and ginger extract. The label suggests two capsules daily in the morning, with or without food. Read more on our cordyceps ingredient page.

Comparing mushrooms? See lion’s mane vs cordyceps and the benefits of adaptogenic mushrooms, or browse all our guides in the Learn center.

Sources

• Sung GH et al. Phylogenetic classification of Cordyceps and the clavicipitaceous fungi. Stud Mycol, 2007. PubMed
• Hughes DP et al. Behavioral mechanisms and morphological symptoms of zombie ants dying from fungal infection. BMC Ecol, 2011. PubMed
• Robert VA, Casadevall A. Vertebrate endothermy restricts most fungi as potential pathogens. J Infect Dis, 2009. PubMed
• World Health Organization. WHO releases first-ever list of health-threatening fungi. News release, 2022. WHO
• LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Cordyceps. National Institute of Diabetes and Digestive and Kidney Diseases. NCBI Bookshelf
• Shao J et al. Molecular Mechanisms of Temperature-Regulated Cordycepin Biosynthesis in Cordyceps militaris. J Fungi (Basel), 2026. PubMed
• Garcia-Solache MA, Casadevall A. Global warming will bring new fungal diseases for mammals. mBio, 2010. PubMed
• Park HJ. Influence of Culture Conditions on Bioactive Compounds in Cordyceps militaris: A Comprehensive Review. Foods, 2025. PubMed
• Yan J et al. Analysis of Codon Usage Bias Between Entomopathogenic Fungus Ophiocordyceps sinensis and Its Host, Thitarodes xiaojinensis. Biology (Basel), 2026. PubMed
• He Z et al. The Conservation Crisis of Ophiocordyceps sinensis: Strategies, Challenges, and Sustainable Future of Artificial Cultivation. J Fungi (Basel), 2025. PubMed

Frequently Asked Questions

Can cordyceps infect humans?

No. Cordyceps fungi infect insects and other arthropods. Human body temperature and the immune system keep out most fungi, and cordyceps is not among the fungi known to cause disease in people.

Is cordyceps a virus?

No. It is a fungus. The idea of a "cordyceps virus" comes from fiction, not biology.

Is the zombie ant fungus real?

Yes. Ophiocordyceps unilateralis and its relatives infect carpenter ants, which leave their nests, bite into a leaf vein and die there, where the fungus grows and spreads.

Can cordyceps take over the human brain?

No. The brain-steering behavior is specific to ants infected by their own Ophiocordyceps species. Most fungi cannot even grow at human body temperature.

Could cordyceps evolve to infect humans?

Researchers have suggested a warming climate could favor heat-tolerant fungi in general. Cordyceps would need to survive human body heat, get past the immune system and live in a host nothing like its insects.

What are the real cordyceps dangers?

For supplements, mild stomach upset, dry mouth or rash are the side effects reported. Check with your clinician first if you take blood thinners, blood sugar or immune-suppressing medication, or are pregnant or breastfeeding.

Is the cordyceps in supplements the same as the zombie ant fungus?

No. Supplements use Cordyceps militaris or Ophiocordyceps sinensis, grown on purpose. The zombie ant fungus is a different species that is not used in supplements.

Is cordyceps a mushroom?

Cordyceps militaris forms a bright orange, club-shaped fruiting body, the mushroom part that many supplements use. The rest of its life is spent as threads (mycelium) inside its host or growing medium.

These statements have not been evaluated by the Food and Drug Administration. This content is for education and is not medical advice. Our products are not intended to diagnose, treat, cure or prevent any disease. Talk with a healthcare provider before starting a new supplement if you are pregnant, breastfeeding or taking medication.