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Rhodiola rosea and mental fatigue: grade C

Limited evidence. Direction: Benefit.

C LimitedSingle research groupShort-term only

Educational guidance, not medical advice

Why this grade

Rubric condition met: >=2 RCTs with mostly consistent results, including one RCT with n >= 100 (161 cadets); A not met: no meta-analysis, and all included trials at high or unclear risk of bias

Three placebo-controlled trials of the SHR-5 extract from 2000-2003 (night-duty physicians, students in exams, military cadets) reported less mental fatigue; they share a co-author. The best-reported trial, a registered 42-day RCT in shift-working nursing students, found fatigue worsened versus placebo. A 2012 systematic review found 3 of 5 mental-fatigue RCTs positive but judged every included study at high or unclear risk of bias. Graded C under policy rule G3: there is no meta-analysis of mental fatigue in healthy adults, and the registered trial from a different research group, funded by the Government of Alberta through AVAC Ltd., found fatigue worsened versus placebo.

How we grade evidence

Studies this grade rests on

EffectMixedNo effectSize shows participants (n)2000200520102015Systematic reviewRCTCrossover RCTShevtsov 2003, 2003: RCT, n = 161, result not recordedOlsson 2009, 2009: RCT, n = 60, result not recordedDarbinyan 2000, 2000: crossover RCT, n = 56, result not recordedPunja 2014, 2014: RCT, n = 48, result not recordedSpasov 2000, 2000: RCT, n not recorded, result not recordedHung 2011, 2011: systematic review, n not recorded, result not recordedIshaque 2012, 2012: systematic review, 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
Spasov 20002000RCTnot recordedresult not recorded
Darbinyan 20002000crossover RCT56result not recorded
Shevtsov 20032003RCT161result not recorded
Olsson 20092009RCT60result not recorded
Hung 20112011systematic reviewnot recordedresult not recorded
Ishaque 20122012systematic reviewnot recordedresult not recorded
Punja 20142014RCT48result not recorded

A randomised, double-blind, placebo-controlled, parallel-group study of the standardised extract shr-5 of the roots of Rhodiola rosea in the treatment of subjects with stress-related fatigue.

Olsson EM, von Schéele B, Panossian AG. A randomised, double-blind, placebo-controlled, parallel-group study of the standardised extract shr-5 of the roots of Rhodiola rosea in the treatment of subjects with stress-related fatigue Planta Med, 2009. PMID 19016404

Result not recorded
Design
Phase III randomized, double-blind, placebo-controlled, parallel-group trial (28 days)
Sample
n = 60
Population
Adults aged 20-55 meeting Swedish diagnostic criteria for fatigue syndrome (clinical population)
Funding
not stated

Rhodiola rosea for mental and physical fatigue in nursing students: a randomized controlled trial.

Punja S, Shamseer L, Olson K. Rhodiola rosea for mental and physical fatigue in nursing students: a randomized controlled trial PLoS One, 2014. PMID 25268730

Result not recorded
Design
Parallel-group, randomized, double-blind, placebo-controlled trial (42 days)
Sample
n = 48
Population
Nursing students on shift work, aged 18-55
Funding
Alberta Agriculture and Rural Development, Government of Alberta, through AVAC Ltd. (competing-interests statement)

A randomized trial of two different doses of a SHR-5 Rhodiola rosea extract versus placebo and control of capacity for mental work.

Shevtsov VA, Zholus BI, Shervarly VI. A randomized trial of two different doses of a SHR-5 Rhodiola rosea extract versus placebo and control of capacity for mental work Phytomedicine, 2003. PMID 12725561

Result not recorded
Design
Randomized, double-blind, placebo-controlled, parallel-group trial with an extra non-treatment group (single dose)
Sample
n = 161
Population
Military cadets aged 19-21 under fatigue and stress
Funding
not stated

A double-blind, placebo-controlled pilot study of the stimulating and adaptogenic effect of Rhodiola rosea SHR-5 extract on the fatigue of students caused by stress during an examination period with a repeated low-dose regimen.

Spasov AA, Wikman GK, Mandrikov VB. A double-blind, placebo-controlled pilot study of the stimulating and adaptogenic effect of Rhodiola rosea SHR-5 extract on the fatigue of students caused by stress during an examination period with a repeated low-dose regimen Phytomedicine, 2000. PMID 10839209

Result not recorded
Design
Randomized, double-blind, placebo-controlled pilot trial (20 days)
Population
Foreign students during an examination period
Funding
not stated

Rhodiola rosea in stress induced fatigue--a double blind cross-over study of a standardized extract SHR-5 with a repeated low-dose regimen on the mental performance of healthy physicians during night duty.

Darbinyan V, Kteyan A, Panossian A. Rhodiola rosea in stress induced fatigue--a double blind cross-over study of a standardized extract SHR-5 with a repeated low-dose regimen on the mental performance of healthy physicians during night duty Phytomedicine, 2000. PMID 11081987

Result not recorded
Design
Randomized, double-blind, placebo-controlled crossover trial (two 2-week periods)
Sample
n = 56
Population
Young healthy physicians on night duty
Funding
not stated

The effectiveness and efficacy of Rhodiola rosea L.: a systematic review of randomized clinical trials.

Hung SK, Perry R, Ernst E. The effectiveness and efficacy of Rhodiola rosea L.: a systematic review of randomized clinical trials Phytomedicine, 2011. PMID 21036578

Result not recorded
Design
Systematic review of 11 placebo-controlled RCTs
Population
Healthy volunteers and patients
Funding
not stated

Rhodiola rosea for physical and mental fatigue: a systematic review.

Ishaque S, Shamseer L, Bukutu C. Rhodiola rosea for physical and mental fatigue: a systematic review BMC Complement Altern Med, 2012. PMID 22643043

Result not recorded
Design
Systematic review of 11 controlled trials (10 RCTs, 1 controlled clinical trial)
Population
Healthy and clinical populations with physical or mental fatigue
Funding
Canadian Foundation for Innovation; Alberta Value-Added Corporation (AVAC); Alberta Crop Industry Development Fund (ACIDF); Alberta Agriculture and Rural Development (full-text financial disclosure)

Search and history

Search (): rhodiola[ti] AND (mental fatigue[tiab] OR "mental performance"[tiab] OR "capacity for mental work"[tiab])

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