Panax ginseng
Panax ginseng C.A. Meyer root extract, 1–2 g/day of a 20% ethanol extract, or Korean Red Ginseng 2–3 g/day
Moderate
Some good studies, not many repeats
Nineteen RCTs exist and the general-fatigue subgroup is significant, but the primary pooled analysis was null and every dedicated stress trial found no between-group difference on stress scales or cortisol.
Across 19 studies it helped with everyday tiredness by a modest amount, but not with tiredness caused by an illness.
Meta-analysis (19 RCTs): overall fatigue severity SMD −0.36 (95% CI −0.82 to 0.11, not significant); general non-disease fatigue SMD −0.48 (95% CI −0.71 to −0.25).
Ginsenosides reduce circulating reactive oxygen species and malondialdehyde and raise glutathione reductase activity, and modulate catecholamine release — an antioxidant and sympatho-modulatory action rather than direct HPA suppression.
People with general, non-disease-specific fatigue — that subgroup is where the pooled effect holds. People seeking cortisol or stress-scale improvement should not expect a result.
What to buy
- ✓Panax ginseng C.A. Meyer root extract, 1–2 g/day of a 20% ethanol extract, or Korean Red Ginseng 2–3 g/day
- ✓1–2 g/day of standardised extract; 3 g/day of Korean Red Ginseng failed to beat placebo on fatigue in one trial
- ✓Third-party tested (USP, NSF, Informed Sport)
- ✕Proprietary blends that hide the dose per ingredient
- ✕Unstandardised extracts with no active-compound percentage
- · Insomnia, hypertension, diarrhoea and skin rash are the common adverse effects; this one can worsen your sleep metrics.
- · 'Ginseng abuse syndrome' reported at 7–15 g/day, resolving on reduction to 1.7 g/day.
- · Avoid in pregnancy and lactation — teratogenicity at high ginsenoside doses in animals.
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The category's default: Korean Red Ginseng at the 1–2 g range, with seventeen thousand ratings. Check that ginsenoside percentage is printed, not just milligrams of root.
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Liquid vials — the traditional Korean presentation and the easiest way to hit 2–3 g without swallowing six capsules.
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A standardised root extract with the ginsenoside content declared, and four thousand ratings — the cleanest label of the three.
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See all on AmazonEvery result, next to the line that means no effect
Each diamond is a study's best estimate. The thin line shows how sure the study was: the shorter the line, the more certain the result.
- Fatigue severity, all RCTsSMD · Meta-analysis 2023, 19 RCTs — not significant−0.36−0.82 … +0.11
- Fatigue severity, general fatigueSMD · Meta-analysis 2023, subgroup, p<0.0001−0.48−0.71 … −0.25
- Fatigue severity, chronic fatigueSMD · Meta-analysis 2023, subgroup, p=0.03−0.30−0.56 … −0.03
- Salivary cortisolnmol/L · RCT 2020, n=50, KRG 3 g, 6 wks — no significant change0.00[not given]
Each unit gets its own scale, so numbers are never mixed on one line. When a study gave no range, we leave it blank instead of inventing one.
5 studies over 10 years
The studies
- 1.Ginseng and ginseng herbal formulas for symptomatic management of fatigue: a systematic review and meta-analysisJournal of Integrative and Complementary Medicine · 2023 · meta-analysis · 19 experiments
No significant overall reduction in fatigue (SMD −0.36, 95% CI −0.82 to 0.11, p=0.13); significant only for general fatigue (−0.48, −0.71 to −0.25) and chronic fatigue (−0.30, −0.56 to −0.03). Effect sizes small, no excess adverse events.
- 2.Antifatigue effects of Panax ginseng C.A. Meyer: a randomised, double-blind, placebo-controlled trialPLOS ONE · 2013 · rct · n = 90
1 g and 2 g/day for 4 weeks cut fatigue on the numerical rating scale and VAS versus placebo (p<0.01) and lowered reactive oxygen species and malondialdehyde (p<0.05); no cortisol measured.
- 3.Efficacy of Korean red ginseng (Panax ginseng) for middle-aged and moderate level of chronic fatigue patients: a randomized, double-blind, placebo-controlled trialComplementary Therapies in Medicine · 2020 · rct · n = 50
3 g/day for 6 weeks improved Fatigue Severity Scale within-group (p<0.001) but so did placebo (p=0.002); between-group difference was null (p=0.846), and salivary cortisol and oxidative markers did not change.
- 4.Effect of Korean Red Ginseng in individuals exposed to high stress levels: a 6-week, double-blind, randomized, placebo-controlled trialJournal of Ginseng Research · 2019 · rct · n = 63
2 g/day for 6 weeks lowered epinephrine (F=4.35, p=0.043) but produced no significant change on the Perceived Stress Scale, Stress Response Inventory, BDI or POMS. Cortisol was not measured.
- 5.The effects of Korean Red Ginseng on stress-related neurotransmitters and gene expression: a randomized, double-blind, placebo-controlled trialJournal of Ginseng Research · 2023 · rct · n = 90
2 g/day for 8 weeks altered epinephrine (p=0.012) and, in the increased-stress subgroup, cortisol (p=0.019) and serotonin (p=0.005); but the Stress Response Inventory showed no between-group difference (p=0.228).
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