Herb library · Mushroom · Ophiocordyceps sinensis (formerly Cordyceps sinensis), Cordyceps militaris
Cordyceps
A fungus that grows out of caterpillars in the mountains of Tibet and southwest China, sold today (mostly as a lab-grown version) for energy, stamina and sexual health. Small trials found no effect on exercise performance.
Traditional use
Used in traditional Chinese medicine for over 1,500 years for fatigue, aging, kidney, liver and heart conditions, and sexual problems. Most supplements today are not made from the wild fungus but from a lab-grown strain called Cs-4, and are promoted for energy, athletic performance and immunity.
What studies show
- Limited· shows no benefit
Exercise performance: in two small placebo-controlled trials (22 male cyclists for 5 weeks; 15 adults aged 50 to 75 for 12 weeks), Cs-4 cordyceps did not improve endurance or oxygen uptake compared with placebo.
- Insufficient
Fatigue, blood sugar, sexual function and other uses: LiverTox says none of the effects seen in the lab and in animals has been shown convincingly in clinical trials in people.
Be careful of
Cautions
- NoteUsually well tolerated. Side effects can include stomach discomfort, diarrhea, dry mouth, nausea, poor appetite and rash.
- ConditionNo acute liver injury has been reported. One 2023 case described a rare chronic liver condition with portal hypertension in a woman on long-term cordyceps, which improved when she stopped; LiverTox calls the link uncertain.
- Ask a clinicianTalk with a clinician or pharmacist before using this if you take prescription medicines, are pregnant or breastfeeding, or are giving it to a child.
From the old books
What herbals and dispensaries of the past printed. History, in their words.
“This fungus, described by the Chinese as a plant in summer and an insect in winter, grows upon the pupa of a kind of caterpillar as a parasite.”
Sources
- Cordyceps (LiverTox) (opens in a new tab) · NIH · read September 25, 2026
Reviewed September 25, 2026.