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What is cordycepin? A molecule from Cordyceps mushrooms

What is cordycepin? A natural adenosine analog discovered in 1950 in Cordyceps fungi. Receptor mechanism and in vitro research, no promises.

Mateusz Rosa

TCM therapist · Doctor of Acupuncture (WFAS) · author of a book on functional mushrooms

5 min read

What is cordycepin? A molecule from Cordyceps mushrooms
Contents

What is cordycepin? Cordycepin (chemical name: 3′-deoxyadenosine) is a natural analog of adenosine, a purine nucleoside that builds DNA, RNA and ATP. The cordycepin molecule is missing one hydroxyl group at the 3′ position of its ribose, a small chemical change with large functional consequences.

The compound was discovered in 1950 in extracts of Cordyceps militaris by Cunningham and colleagues [Cunningham et al. 1950], the first documented isolation of a compound of this class from a natural source.

What is cordycepin, chemically?

Cordycepin is a purine nucleoside with the formula C₁₀H₁₃N₅O₃ and a molecular weight of 251.24 g/mol, made of the nitrogenous base adenine (identical to adenosine) and the sugar 3′-deoxyribose, a ribose derivative lacking the 3′-OH group. Cells phosphorylate cordycepin to its triphosphate, an ATP analog [Hawley et al. 2020], but the missing 3′-OH group blocks RNA chain elongation.

This single-atom difference earned cordycepin its historical name, "natural chain terminator". The compound dissolves in water and ethanol and crystallizes as a white powder.

How does cordycepin modulate adenosine receptors?

Cordycepin has affinity to all four adenosine receptor subtypes, A1, A2A, A2B and A3 [Du et al. 2021, DOI: 10.26502/jbb.2642-91280035]. Under experimental conditions this modulates neuroinflammatory signaling via A1, vasodilation via A2A, and immune signaling via A2B and A3.

Adenosine in the body signals a cell's energy state, slowing metabolic processes and dilating blood vessels. Cordycepin acts on the same receptors as an analog, not as a blocker.

How does cordycepin act as an RNA terminator?

After intracellular phosphorylation to its triphosphate form, cordycepin can be incorporated by RNA polymerases into a growing RNA strand. The missing 3′-OH group prevents further chain elongation, resulting in transcription termination under experimental conditions.

In practice this mechanism is limited by ADA (adenosine deaminase), an enzyme widely present in the body that rapidly converts cordycepin into the far less active 3′-deoxyinosine [Chen et al. 2023, DOI: 10.1002/ptr.7921]. This is the main factor limiting cordycepin's bioavailability in oral supplementation.

What anti-inflammatory profile is observed in research?

In animal models and cell cultures, cordycepin shows an effect on reducing pro-inflammatory cytokine expression (TNF-α, IL-1β, IL-6) via NF-κB pathway modulation, and on supporting antioxidant enzymes via Nrf2 activation [Chen et al. 2023]. This is preclinical research, not evidence of a clinical effect in humans.

Chen and co-authors summarize cordycepin as a bioactive compound from Cordyceps militaris with a broad pharmacological profile in vitro, though rapidly deaminated by ADA in vivo, which shortens its half-life.

How does cordycepin differ from adenosine?

Both molecules share an identical nitrogenous base (adenine) but differ in sugar: adenosine has D-ribose, cordycepin has 3′-deoxyribose. Adenosine is phosphorylated to ATP, cordycepin to its analog lacking the 3′-OH group (cordycepin triphosphate). Once incorporated into RNA, adenosine allows normal chain elongation, while cordycepin terminates it.

The practical consequence: supplement makers look for ways to increase cordycepin's bioavailability (encapsulation, micronization), because classic oral forms deliver a compound that is largely inactivated by ADA soon after intake.

Where does cordycepin naturally occur?

Cordycepin is almost exclusively associated with the Cordyceps genus. The highest natural concentrations occur in Cordyceps militaris, the dominant source in modern supplementation. Cordyceps sinensis (Ophiocordyceps sinensis), the classic TCM fungus from the Tibetan Plateau, contains only trace amounts in nature.

Cordycepin does not occur in other functional mushrooms such as Reishi, Lion's Mane or Chaga. It is a specific marker of the Cordyceps genus: a mushroom blend advertising cordycepin must contain C. militaris.

What does cordycepin not promise?

Cordycepin is an interesting molecule with a described in vitro mechanism, not a remedy for infections nor a replacement for therapy prescribed by a doctor. Most documented pharmacological effects occur in cell cultures or animal models, and clinical studies on isolated cordycepin in humans are practically nonexistent. For how the whole Cordyceps fungus works in a supplementation practice, read our article How does Cordyceps work.

Our raw material is a 10:1 fruiting-body extract, standardized to over 30% beta-glucans (EUROFINS lab), free of maltodextrin, and tested for heavy metals and pesticides. Cordycepin is naturally present, though we do not state an mg-per-serving figure as a claim, since it is not an approved EFSA marker.

References

Show sources (5)
  • Cunningham KG, Manson W, Spring FS, Hutchinson SA. (1950). Cordycepin, a metabolic product isolated from cultures of Cordyceps militaris (Linn.) Link. Nature, 166: 949.
  • Chen M, Luo J, Jiang W et al. (2023). Cordycepin: A review of strategies to improve the bioavailability and efficacy. Phytotherapy Research, 37(9): 3839-3858. DOI: 10.1002/ptr.7921
  • Du J, Kan W, Bao H et al. (2021). Interactions Between Adenosine Receptors and Cordycepin from Cordyceps Militaris. Journal of Biotechnology and Biomedicine, 4: 26-62. DOI: 10.26502/jbb.2642-91280035
  • Hawley SA, Ross FA, Russell FM et al. (2020). Mechanism of Activation of AMPK by Cordycepin. Cell Chemical Biology, 27(2): 214-222.e4. DOI: 10.1016/j.chembiol.2020.01.004
  • Hirsch KR, Smith-Ryan AE, Roelofs EJ et al. (2017). Cordyceps militaris Improves Tolerance to High-Intensity Exercise After Acute and Chronic Supplementation. Journal of Dietary Supplements, 14(1): 42-53. DOI: 10.1080/19390211.2016.1203386

See also: How does Cordyceps work · research on functional mushrooms.

Cordyceps in scientific research

What was studied, on how many people and with what level of evidence. This overview describes studies, not the effects of a product.

9 human studies · 3 placebo-controlled RCTs · 2000–2026

Show all 18 studies
  • Zhou J. et al., 2021

    C

    RCT, double-blind, placebo-controlled

    59 people

    The study examined Cordyceps militaris as an add-on to duloxetine for insomnia associated with depression, in a group of 59 people, using a double-blind, placebo-controlled RCT design.

    PMID 34858228
  • Ontawong A. et al., 2024

    C

    RCT

    40 healthy adults

    The study examined the effect of a Cordyceps militaris beverage on immune response in 40 healthy adults, using an RCT design.

    PMID 38580687
  • Dubhashi S. et al., 2023

    C

    RCT, double-blind, placebo-controlled

    65 enrolled, 58 evaluated

    The study examined Cordyceps militaris in mild-to-moderate COVID-19, using a double-blind, placebo-controlled RCT, with 65 people enrolled (58 evaluated).

    PMID 37727187
  • Yang E.-J. et al., 2026

    E

    narrative review · preclinical studies (in vitro and rodent)

    not applicable

    The narrative review collected in vitro, in vivo and clinical data on Cordyceps militaris.

    PMID 41432716
  • Shu M.-Y. et al., 2025

    B

    systematic review with meta-analysis

    14 RCTs, 528 athletes

    The systematic review with meta-analysis collected 14 RCTs (528 athletes) on functional mushroom supplementation in athletes; the review covers multiple mushroom species at once, not only Cordyceps militaris.

    PMID 41280379
  • Choi E. et al., 2020

    E

    animal study (mice) · preclinical studies (in vitro and rodent)

    not applicable

    The mouse study examined the effect of Cordyceps militaris on physical performance.

    PMID 33312018
  • Hirsch K.R. et al., 2017

    C

    RCT, double-blind, placebo-controlled (mushroom blend, not an isolated species)

    28 (acute phase), 10 (chronic phase)

    The study examined the effect of a mushroom blend containing C. militaris (4 g/day) on VO2max, time to exhaustion, ventilatory threshold and power in a cycle ergometer test, using 1-week and 3-week protocols in recreationally active young adults (mean age 22.7). Limitations: n=10 in the chronic phase, a multi-ingredient preparation not isolating the species.

    PMID 27408987
  • Jędrejko M. et al., 2026

    E

    narrative review of human studies · preclinical studies (in vitro and rodent)

    5 studies, 321 participants aged 16-35

    The narrative review collected 5 intervention studies (2017-2024) on ergogenic effects and post-exercise recovery with supplementation in humans. Small samples, heterogeneous participants and protocols, incomplete randomisation reporting, most studies not registered.

    PMID 41829950
  • Tuli H.S. et al., 2014

    E

    narrative review · preclinical studies (in vitro and rodent)

    not applicable

    The review discussed the pharmacological potential of the genus Cordyceps, with particular focus on cordycepin, based on in vitro/in vivo data.

    DOI 10.1007/s13205-013-0121-9
  • Olatunji O.J. et al., 2018

    E

    narrative review (whole genus Cordyceps) · preclinical studies (in vitro and rodent)

    not applicable

    The review collected traditional uses, phytochemistry and pharmacology of the entire genus Cordyceps without separating species.

    PMID 29775778
  • Du J. et al., 2021

    E

    narrative review · preclinical studies (in vitro and rodent)

    not applicable

    The paper discussed mechanisms of cordycepin interaction with adenosine receptors and hypothetically linked this to brain protection and COVID-19. Purely theoretical, with no original data.

    DOI 10.26502/jbb.2642-91280035
  • Ko K.M., Leung H.Y., 2007

    E

    narrative review · preclinical studies (in vitro and rodent)

    not applicable

    The review discussed TCM tonic herbs (Cordyceps as one of several) in the context of ATP, antioxidation and immunomodulation. Does not isolate Cordyceps.

    PMID 17386115
  • Chen S. et al., 2010

    D

    pilot RCT

    20 enrolled, 15 completed

    The pilot randomised study examined the effect of the Cs-4 preparation (a fermented Cordyceps sinensis product) on physical performance in older adults, 20 enrolled, 15 completed.

    PMID 20804368
  • Parcell A.C. et al., 2004

    C

    RCT, double-blind

    22 cyclists

    The double-blind RCT examined the effect of the CordyMax Cs-4 preparation (Cordyceps sinensis) on performance in 22 cyclists.

    PMID 15118196
  • Yu X. et al., 2019

    B

    systematic review with meta-analysis

    14 RCTs, 1192 people

    The systematic review with meta-analysis collected 14 RCTs (1192 people) on Cordyceps sinensis in stable chronic obstructive pulmonary disease (COPD).

    PMID 31073318
  • Wu F. et al., 2025

    B

    systematic review with meta-analysis of RCTs

    15 RCTs, 1310 people

    The meta-analysis collected RCTs on oral Cordyceps sinensis as adjunct therapy in patients with renal dysfunction (creatinine, oliguria duration, urine osmolality). Small samples, short observation periods, predominance of studies from China.

    PMID 39839641
  • Kumar R. et al., 2011

    E

    animal study (rats) · preclinical studies (in vitro and rodent)

    not applicable

    The rat study examined exercise endurance capacity and skeletal muscle metabolic regulators after Cordyceps sinensis administration.

    PMID 21549819
  • Chiou W.F. et al., 2000

    E

    animal (rats) + in vitro (aorta) · preclinical studies (in vitro and rodent)

    not applicable

    The study in anaesthetised rats and isolated aortic rings examined the effect of a Cordyceps sinensis protein fraction on arterial pressure (intravenous administration) and vascular relaxation. Animal model, intravenous administration, does not translate to an oral supplement.

    PMID 10755473

Evidence levels: A · Cochrane review · B · systematic review · C · placebo RCT · D · pilot RCT · E · preclinical studies

What these studies don't say

  • Samples are usually small, most from a single population.
  • Results describe research interventions, not a dietary supplement.
  • The presence of a study is not a health claim.

Source: Aloha Fungi literature review, 1 September 2026; entries verified via PubMed or by DOI (Crossref). See the research

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