Chronic Fatigue Syndrome

Asian ginseng has no trial in diagnosed CFS, but its effect on general fatigue is consistent: a meta-analysis of 12 RCTs (630 participants) found a significant effect on fatigue (SMD 0.34) with some physical-performance benefit ^{8Reference 8Bach et al. · 2016Meta-analysisEfficacy of ginseng supplements on fatigue and physical performance — meta-analysis of RCTsView study →}, and two systematic reviews concluded ginseng may reduce fatigue, particularly in chronic illness ^{9,10Reference 9Arring et al. · 2018Systematic reviewGinseng as a treatment for fatigue — systematic reviewView study →Reference 10Li et al. · 2023Meta-analysisGinseng and ginseng herbal formulas for symptomatic management of fatigue — systematic review and meta-analysisView study →}.

Effect sizes are small-to-moderate, outcome scales heterogeneous, and part of the positive signal comes from American ginseng (P. quinquefolius) rather than Asian ginseng.

Cordyceps has no CFS-specific trial. The nearest human evidence is the fatigue/endurance literature, which is mixed: a well-controlled RCT found Cs-4 (3 g/day, 5 weeks) did not improve performance in trained cyclists ^{3Reference 3Parcell AC et al. · 2004RCTCordyceps Sinensis (CordyMax Cs-4) supplementation does not improve endurance exercise performance — randomised, placebo-controlled trialView study →}, while a double-blind trial in healthy older adults reported ~8–11% gains in metabolic and ventilatory thresholds after 12 weeks of Cs-4 ^{4Reference 4Chen S et al. · 2010RCTEffect of Cs-4 (Cordyceps sinensis) on exercise performance in healthy older subjects: a double-blind, placebo-controlled trial — randomised, double-blind, placebo-controlled trialView study →}.

Combined with the herb’s classical Kidney/Lung-tonic reputation for exhaustion and recovery after illness, the case is an adaptogenic and vitality rationale rather than a fatigue endpoint. Benefit appears mainly in older/less-trained people on mycelial preparations, not the dried fruiting body.

A randomised trial of eleuthero in chronic fatigue (n=96) found no overall benefit versus placebo, though a pre-specified subgroup with less severe, longer-duration fatigue did improve ^{5Reference 5Hartz AJ et al. · 2004RCTRandomized controlled trial of Siberian ginseng for chronic fatigue — RCTView study →}. The EMA’s traditional-use asthenia (fatigue and weakness) approval ^{6,7Reference 6Patyra A et al. · 2025ReviewEleutherococcus root: a comprehensive review of its phytochemistry and pharmacological potential in the context of its adaptogenic effect — reviewView study →Reference 7European Medicines Agency · 2006ReviewEuropean Medicines Agency, Committee on Herbal Medicinal Products (HMPC). (2006/2014). Community herbal monograph on Eleutherococcus senticosus (Rupr. et Maxim.) Maxim., radix — Doc. EMEA/HMPC/244569/2006 (traditional use for asthenia). https://www.ema.europa.eu/en/medicines/herbal/eleutherococci-radixView study →} is the closest formal recognition, but it is traditional-use, not well-established-efficacy — the flagship CFS trial was negative on its primary endpoint.

Guarana has no CFS-specific trial. Its use rests on its caffeine-driven acute stimulant effect — a meta-analysis of eight RCTs found faster reaction time (Hedge’s g = 0.20) but no accuracy or dose-response benefit ^{11,12Reference 11Hack et al. · 2023Meta-analysisEffect of guarana (Paullinia cupana) on cognitive performance — systematic review and meta-analysisView study →Reference 12Kennedy et al. · 2004RCTImproved cognitive performance following guarana extract — randomised, placebo-controlled trialView study →}, plus small ergogenic/anti-fatigue gains in exercise trials attributed to reduced perceived effort ^{13,14Reference 13Penna et al. · 2024RCTGuarana but not low-dose caffeine improves cycling time-trial performance — randomised controlled trialView study →Reference 14Estrázulas et al. · 2024RCTAcute ingestion of guarana on soccer player performance — randomised controlled trialView study →} — layered on its traditional Amazonian use to decrease fatigue ^{15Reference 15Basile et al. · 2005In vitroAntibacterial and antioxidant activities of ethanol extract from Paullinia cupana — in vitroView study →}.

This is a caffeine/anti-fatigue rationale, not a fatigue-syndrome endpoint, with no evidence guarana beats plain caffeine.

Ashwagandha has no CFS-specific trial. Its use for fatigue rests on the herb’s Rasayana (rejuvenative tonic) tradition plus its cortisol/HPA-axis and vitality signals from the stress and exercise-performance trials ^{1,2Reference 1Chandrasekhar K et al. · 2012RCTA prospective, randomised double-blind, placebo-controlled study of a high-concentration full-spectrum ashwagandha root extract in reducing stress and anxiety — RCTView study →Reference 2Wankhede S et al. · 2015RCTExamining the effect of Withania somnifera supplementation on muscle strength and recovery — a randomised controlled trialView study →} — i.e. an adaptogenic rationale, not a fatigue endpoint.

Maca is a traditional Andean vitality/adaptogen tonic used for stamina and fatigue. The physical-performance literature is weak and animal-dominated, and its one placebo-controlled human trial was null. There is no CFS trial.

Milk thistle’s use for fatigue rests on the traditional liver-tonic / ‘melancholy’ framing. There is no fatigue or CFS trial.

American skullcap is a traditional trophorestorative nervine for nervous exhaustion and burnout. There is no trial or mechanism for a fatigue endpoint.

Suma is used as an adaptogenic ‘Brazilian ginseng’ tonic. The concrete anti-stress data belong to a sibling species (P. glomerata), so the CFS use rests on tradition and ecdysteroid read-across.