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Panax ginseng and mental fatigue: grade C

Limited evidence. Direction: Benefit.

C LimitedSubjective outcome only

Educational guidance, not medical advice

Why this grade

Rubric condition met: C (conservative reading of mixed evidence, citation-rules 9): positive pooled results exist only in subgroups or small meta-analyses; the largest meta-analysis found no overall effect

A 2016 meta-analysis found reduced fatigue in four RCTs (SMD 0.34) but its authors judged the evidence insufficient. A 2023 meta-analysis of 19 RCTs found no significant overall reduction in fatigue severity, with a small benefit only for general, non-disease fatigue (SMD -0.48) and ginseng herbal formulas. In healthy young adults, two small crossover trials of one extract reduced subjective mental fatigue during demanding tasks. The grader may consider B (meta-analysis with high heterogeneity); C is proposed because the evidence is mixed and most fatigue trials were in people with chronic illness.

How we grade evidence

Studies this grade rests on

EffectMixedNo effectSize shows participants (n)20052010201520202025Meta-analysisSystematic reviewCrossover RCTBach 2016, 2016: meta-analysis, n = 630, result not recordedReay 2005, 2005: crossover RCT, n = 30, result not recordedReay 2006, 2006: crossover RCT, n = 27, result not recordedArring 2018, 2018: systematic review, n not recorded, result not recordedLi 2023, 2023: meta-analysis, n not recorded, result not recorded
each study this grade rests on, by publication year and design. Solid: effect versus the comparator; half-filled: mixed; hollow: no effect; dashed: result not recorded yet. Larger marks had more participants.
Show the numbers
StudyYearDesignParticipantsResult
Reay 20052005crossover RCT30result not recorded
Reay 20062006crossover RCT27result not recorded
Bach 20162016meta-analysis630result not recorded
Arring 20182018systematic reviewnot recordedresult not recorded
Li 20232023meta-analysisnot recordedresult not recorded

Effects of Panax ginseng, consumed with and without glucose, on blood glucose levels and cognitive performance during sustained 'mentally demanding' tasks.

Reay JL, Kennedy DO, Scholey AB. Effects of Panax ginseng, consumed with and without glucose, on blood glucose levels and cognitive performance during sustained 'mentally demanding' tasks J Psychopharmacol, 2006. PMID 16401645

Result not recorded
Design
Double-blind, placebo-controlled, balanced crossover trial
Sample
n = 27
Population
Healthy young adults
Funding
not stated in PubMed or Crossref records

Single doses of Panax ginseng (G115) reduce blood glucose levels and improve cognitive performance during sustained mental activity.

Reay JL, Kennedy DO, Scholey AB. Single doses of Panax ginseng (G115) reduce blood glucose levels and improve cognitive performance during sustained mental activity J Psychopharmacol, 2005. PMID 15982990

Result not recorded
Design
Double-blind, placebo-controlled, balanced crossover trial (single doses)
Sample
n = 30
Population
Healthy young adults
Funding
not stated in PubMed or Crossref records

Ginseng as a Treatment for Fatigue: A Systematic Review.

Arring NM, Millstine D, Marks LA. Ginseng as a Treatment for Fatigue: A Systematic Review J Altern Complement Med, 2018. PMID 29624410

Result not recorded
Design
Systematic review of 10 studies (narrative synthesis)
Population
People with fatigue, mostly with chronic illness
Funding
not stated in PubMed or Crossref records

Efficacy of Ginseng Supplements on Fatigue and Physical Performance: a Meta-analysis.

Bach HV, Kim J, Myung SK. Efficacy of Ginseng Supplements on Fatigue and Physical Performance: a Meta-analysis J Korean Med Sci, 2016. PMID 27822924

Result not recorded
Design
Meta-analysis of 12 placebo-controlled RCTs
Sample
n = 630
Population
Adults in RCTs of fatigue or physical performance
Funding
National Cancer Center, Korea (Crossref funder list)

Ginseng and Ginseng Herbal Formulas for Symptomatic Management of Fatigue: A Systematic Review and Meta-Analysis.

Li X, Yang M, Zhang YL. Ginseng and Ginseng Herbal Formulas for Symptomatic Management of Fatigue: A Systematic Review and Meta-Analysis J Integr Complement Med, 2023. PMID 36730693

Result not recorded
Design
Systematic review and meta-analysis of 19 RCTs
Population
People with fatigue (general, chronic and disease-related)
Funding
NCI NIH HHS P30 CA008748

Search and history

Search (): ginseng[ti] AND fatigue[tiab] AND (meta-analysis[pt] OR systematic review[pt])

  • Graded C (proposed): Proposed in the monograph draft
  • C to C (approved): Editor sign-off November 13, 2026: grade matches the editor-approved final page