Evidence explainerCordyceps

Is Cordyceps Safe? Short Trials Found No Problems, but Products Vary by Species

Cordyceps products come from different species and growing methods. Short trials report few problems; long-term controlled safety data do not exist yet.

By Kymata Health editorial teamPublished October 9, 2026Last reviewed October 9, 2026

Medical review pending. Written by our editorial team from the studies cited below; a credentialed clinician has not reviewed it yet. Educational only, not medical advice.

Key takeaways

  • In a 4-week placebo-controlled trial of 79 men taking 1.5 g/day of C. militaris, there was no statistically significant adverse reaction [1].
  • In 49 people taking 1.05 g/day of Cordyceps cicadae mycelium for 3 months, kidney and liver tests did not change, but there was no placebo group [2].
  • Trials used different species and products: C. sinensis (CordyMax Cs-4), C. militaris extracts, C. cicadae mycelium and blends [3][1][2][4].
  • Results from one species or product may not apply to another, and no trial in our sources compared species head to head [3][4].

The evidence, graded

Pulled from our monograph evidence tables. Grades follow our evidence-grading policy.

What the safety data show

In the 4-week C. militaris trial (39 on cordyceps, 40 on placebo), researchers ran safety tests alongside the immune measures and found no statistically significant adverse reaction [1].

A 3-month study gave 49 participants 1.05 g/day of freeze-dried Cordyceps cicadae mycelium [2]. Kidney and liver function, electrolytes and blood lipids did not change, and participants reported no side effects [2]. Without a placebo group, it shows only that nothing obvious changed.

Militaris, sinensis and cicadae

The cordyceps products in human trials were not the same thing [3][1][2]:

  • Cordyceps sinensis (CordyMax Cs-4 tablets): 3 g/day for 5 weeks in trained cyclists [3].
  • Cordyceps militaris: an ethanol-processed preparation at 1.5 g/day for immune markers [1], and a blend containing it at 4 g/day for exercise [4].
  • Cordyceps cicadae mycelium grown by liquid fermentation: 1.05 g/day for 3 months [2].

What is missing

None of the trials in our sources ran longer than 3 months, and none compared species directly [2][3]. Anyone taking prescription medicines, pregnant or managing a chronic condition should talk to a clinician before adding cordyceps.

For what the trials found on performance, read cordyceps benefits.

Quick answers

Is cordyceps psychoactive?

The trials in our sources tested exercise, immune markers and cognition; their abstracts do not describe psychoactive effects [1][3].

Which cordyceps species is better?

No trial in our sources compared species; each tested a different product [3][1][2].

Is cordyceps hard on the liver or kidneys?

In a 3-month uncontrolled study of C. cicadae mycelium, kidney and liver tests did not change [2].

Keep reading

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References

  1. [1]Cordyceps militaris Enhances Cell-Mediated Immunity in Healthy Korean Men. J Med Food, 2015. PMID 26284906
  2. [2]Safety Assessment of HEA-Enriched Cordyceps cicadae Mycelium: A Randomized Clinical Trial. J Am Coll Nutr, 2021. PMID 32702252
  3. [3]Cordyceps Sinensis (CordyMax Cs-4) supplementation does not improve endurance exercise performance. Int J Sport Nutr Exerc Metab, 2004. PMID 15118196
  4. [4]Cordyceps militaris Improves Tolerance to High-Intensity Exercise After Acute and Chronic Supplementation. J Diet Suppl, 2017. PMID 27408987

Cordyceps and other dietary supplements are not intended to diagnose, treat, cure or prevent any disease, and these statements have not been evaluated by the FDA. Talk to your clinician or pharmacist before starting a supplement, especially if you take prescription medicines. This page has no product or affiliate links.

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