The Library / Ingredient Library

Cordyceps

A fungus with a thousand-year record at altitude and a modern trial literature on one precise question: how the body uses oxygen under load.

LayerLAYER TWO · daytimeFormextract · 30% polysaccharides · 300 mgSources7 primary

In short

Cordyceps carries one of the most specific propositions in the botanical world: that the body can be helped to use oxygen more efficiently under load. A 2025 meta-analysis pooling 14 randomised trials and 528 participants finds improved aerobic performance. A controlled trial in healthy older adults measured a 10.5 percent rise in metabolic threshold, and three weeks of supplementation improved oxygen use at high intensity in young adults. Alongside that sits a second literature on immune function, with two randomised trials showing increased natural killer cell activity. The 300 mg here is standardised to 30 percent polysaccharides and dosed for the long middle of the day.

Most performance ingredients promise intensity. Cordyceps promises economy: the same work, done on better terms. That is a daytime idea, and it is the reason this fungus sits in the daytime layer.

01A record that started at 4,500 metres

Cordyceps enters the written record through Tibetan and Chinese medicine, harvested on the high plateau and reserved, for most of its history, for people who could afford something rarer than gold by weight. The traditional indications were consistent across a millennium: stamina, breath, and resilience through sustained exertion at altitudes where oxygen is scarce. What changed the ingredient's trajectory was cultivation. Modern fermented and cultivated forms made it possible to produce cordyceps at consistent strength, standardise the polysaccharide fraction, and finally put the old claims into randomised trials. The trials are why this page exists.

02Oxygen economics

Every working day has a threshold: the point where effort stops feeling sustainable and starts drawing down reserves. Exercise science measures this as the ventilatory or metabolic threshold, and it is exactly where cordyceps has produced its most interesting human numbers. In a double blind randomised trial in healthy older adults, twelve weeks of the standardised Cs-4 strain raised metabolic threshold by 10.5 percent against placebo.1 In healthy young adults, a randomised trial found that supplementation improved maximal oxygen uptake and time to exhaustion at high intensity after three weeks, with the effect growing over time rather than appearing at once.2 That time course matters: it is the signature of an ingredient that shifts baseline capacity, not a stimulant that borrows against it.

Definition · The 30 percent standard

Wild cordyceps is one of the most expensive raw materials on earth, which made consistency impossible for centuries. Cultivated extract standardised to 30 percent polysaccharides fixes the studied fraction at a guaranteed strength per dose. That specification is what LAYER TWO carries.

03What the pooled data says

The single-trial story now has a pooled answer. A 2025 systematic review and meta-analysis brought together 14 randomised controlled trials with 528 participants and found improvements in aerobic performance with cordyceps supplementation.3 The trials vary in strain, dose, and population, which is the honest note and the normal condition of a botanical literature at this stage; what stands out is that the direction of effect survives the pooling. Fourteen trials pointing the same way is not an anecdote. It is a signal that has repeated across labs, countries, and two decades.

04The immune keel

The second literature is immunological, and it fits the daytime brief just as directly. Sustained workload and hard training measurably suppress immune function; a daytime layer should push the other way. In an eight week randomised trial in healthy men, cordyceps increased natural killer cell activity against placebo.4 A second randomised trial in 79 adults reproduced the finding with a cordyceps mycelium extract, again against placebo.5 Natural killer cells are the immune system's first responders, and two controlled human trials moving the same marker in the same direction is precisely the kind of concordance a formulation decision can stand on.

05The research horizon

The literature is active on both fronts. A 2024 randomised controlled trial in Scientific Reports extended the human data in healthy adults,6 and mechanistic work continues to map how cordyceps acts on cellular energy metabolism, including effects on ATP production and the adenosine analogue cordycepin.7 Much of the newest work is early and some of it is small, which in this field usually reflects funding rather than merit; the pattern to watch is that each new round of studies has landed on the same side as the last. The picture is sharpening, not resetting.

06Why 300 mg, and why the daytime

LAYER TWO carries ten ingredients built around one job: holding output and defences steady through the long middle of the day. Cordyceps at 300 mg, standardised to 30 percent polysaccharides, is the oxygen economy and immune component of that architecture. It sits in the daytime because that is where the load is: the hours where thresholds get tested and reserves get spent. It is a deliberate dose inside a system designed as a whole, and the system is the point.

In the system

Cordyceps works the daytime alongside magnesium malate and astragalus, each covering a different part of the resilience problem, as the afternoon crash page maps. Build your protocol →

Sources

01
Chen S, et al. Effect of Cs-4 (Cordyceps sinensis) on exercise performance in healthy older subjects: a double-blind, placebo-controlled trial. Journal of Alternative and Complementary Medicine, 2010. Metabolic threshold up 10.5 percent versus placebo.
Moderate · RCT
pubmed.ncbi.nlm.nih.gov · 20804368
02
Hirsch KR, et al. Cordyceps militaris improves tolerance to high-intensity exercise after acute and chronic supplementation. Journal of Dietary Supplements, 2017. VO2max and time to exhaustion improved after three weeks.
Moderate · RCT
doi.org · 10.1080/19390211.2016.1203386
03
Shu Y, et al. Effects of Cordyceps supplementation on aerobic performance: a systematic review and meta-analysis of randomised controlled trials. Frontiers in Nutrition, 2025. 14 RCTs, 528 participants.
Strong · meta-analysis
doi.org · 10.3389/fnut.2025.1670416
04
Kang HJ, et al. Cordyceps militaris enhances cell-mediated immunity in healthy Korean men. Journal of Medicinal Food, 2015. Natural killer cell activity increased over eight weeks versus placebo.
Moderate · RCT
doi.org · 10.1089/jmf.2014.3350
05
Jung SJ, et al. Immunomodulatory effects of a mycelium extract of Cordyceps: a randomised, double-blind, placebo-controlled trial in 79 adults. BMC Complementary and Alternative Medicine, 2019. NK cell activity increased versus placebo.
Moderate · RCT
doi.org · 10.1186/s12906-019-2483-y
06
Ontawong A, et al. Randomised controlled trial of Cordyceps supplementation in healthy adults. Scientific Reports, 2024. Extends the controlled human record in healthy volunteers.
Moderate · RCT
doi.org · 10.1038/s41598-024-58742-z
07
Kumar R, et al. Cordyceps sinensis and cellular energy metabolism under exercise load. Journal of Ethnopharmacology, 2011. Mechanistic work on ATP production and endurance.
Mechanistic · preclinical
doi.org · 10.1016/j.jep.2011.05.030

How we handle evidence. This page is built on the endpoints where cordyceps performs in controlled trials, notes the variety in the underlying literature once, and treats the pooled 2025 data as what it is: a repeating signal. Educational content, not medical advice.

LAYER ZERO · The Library

A body of knowledge on daily performance: the biology of focus, resilience, and recovery, and the reasoning behind the system. Sources are primary literature; claims are graded by strength of evidence. Not medical advice.