Rhodiola Rosea

Rhodiola rosea is a herb in the rhodiola genera (Crassulaceae family) which has traditional usage as an anti-fatigue agent and adaptogen compound, and rhodiola is likely the second most popular adaptogen (second only to panax ginseng).

In regards to fatigue, rhodiola appears to be able to significantly reduce the effects of prolonged and minor physical exhaustion that results in fatigue. This is more related to stress and the 'burnout' effect, or prolonged but low intensity physical exercise. There is some limited evidence that parameters of physical exercise can be improved with rhodiola, but this appears to be limited to untrained persons with numerous studies on trained athletes suggesting that rhodiola does not have an acute ergogenic effect. Despite this, rhodiola appears to be highly reliable in reducing fatigue symptoms and improving symptoms of stress (and secondary to that, well-being) in persons fatigued from non-exercise related stressors.

Rhodiola can improve cognitive functioning in persons who experience a reduction in fatigue, but there is insufficient evidence to support an outright increase in cognition (which should occur in non-fatigued persons) and not enough studies have assessed cognitive decline for conclusions to be made.

Other potential uses of rhodiola include preliminary evidence that it is highly neuroprotective against toxins (requires more evidence) and that ingestion of rhodiola or its active component can reduce stress-induced binge eating in female rats. In the brain, rhodiola appears to be highly serotonergic (increases serotonin) and reduces corticosteroids; the inhibition of monoamine oxidases (MAOs) commonly attributed to rhodiola may not be relevant following oral ingestion of rhodiola, however.

Rhodiola may also promote longevity, with preliminary (non-mammalian) evidence suggesting up to a 20% increase in lifespan secondary to mechanisms that are indepedent of caloric restriction. Although very promising, mammalian evidence is needed to confirm.

One study has found that some commercial Rhodiola products may be diluted or otherwise adulterated.

Supplementation of rhodiola rosea tends to refer to either the SHR-5 extract in particular or an equivalent extract, any that confers both 3% rosavins and 1% salidroside.

Usage of rhodiola as a daily preventative against fatigue has been reported to be effective in doses as low as 50mg.

Acute usage of rhodiola for fatigue and anti-stress has been noted to be taken in the 288-680mg range.

As rhodiola has been shown to have a bell-curve response before, it is recommended to not exceed the aforementioned 680mg dosage as higher doses may be ineffective.

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what effects rhodiola rosea has on your body, and how strong these effects are.

Grade	Level of Evidence [show legend]
	Robust research conducted with repeated double-blind clinical trials
	Multiple studies where at least two are double-blind and placebo controlled
	Single double-blind study or multiple cohort studies
	Uncontrolled or observational studies only

Level of Evidence ? The amount of high quality evidence. The more evidence, the more we can trust the results.	Outcome	Magnitude of effect ? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.	Consistency of research results ? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.	Notes
	Fatigue	Notable	Very High See all 8 studies	The decrease in fatigue appears to be quite strong and somewhat reliable when a low dose is given over a prolonged period of time or a high dose is given acutely; there is one study which has noted an increase in fatigue (relative to placebo) that needs to be expanded upon.
	Cognition	Notable	Very High See all 4 studies	Notably effective assuming fatigue is being reduced. There is insufficient evidence to evaluate rhodiola's effects on cognition without the fatigue reduction aspect
	Subjective Well-Being	Notable	Very High See all 4 studies	Increases in subjective well being and contentment in fatigued or stressed individuals appears to be greater than other supplements.
	Depression	Notable	- See study	Limited evidence, but up to a halving of symptoms has been noted with higher doses of Rhodiola
	C-Reactive Protein	Minor	- See study	A decrease in C-reactive protein has been noted with rhodiola supplementation; practical significance of these results unknown
	Lactate Production	Minor	- See study	A decrease in lactate production has been noted with rhodiola supplementation; practical significance unknown
	Muscle Damage	Minor	Very High See 2 studies	Able to reduce circulating levels of creatine kinase following exercise
	Processing Accuracy	Minor	- See study	Increases in processing accuracy are likely secondary to reductions in fatigue
	Rate of Perceived Exertion	Minor	- See study	Possibly effective if confounded with fatigue (the antifatigue effects may reduce the rate of percieved exertion during submaximal exercise) but there does not appear to be strong effects in maximal effort trials
	Stress	Minor	- See 2 studies	Might be effective, but the reduction in stress (rating scale) appears to be less than that seen with fatigue
	Attention	-	- See study	No significant influences on attention
	Blood Pressure	-	- See study	No significant effects yet noted on blood pressure
	Heart Rate	-	Very High See 2 studies	No significant influences on heart rate found so far
	Lipid Peroxidation	-	Very High See 2 studies	No significant influences on lipid peroxidation biomarkers in serum
	Muscle Oxygenation	-	- See study	No significant effects on oxygenation during exercise or simulated altitude tests
	Power Output	-	- See study	No significant influences on power output
	Reaction Time	-	- See study	No significant influences on reaction time
	VO₂ Max	-	- See study	May slightly improve oxygen consumption during submaximal exercise in untrained persons, but overall the improvement in VO2 max does not appear to be highly potent or reliable.
	Weight	-	- See study	Unable to modify weight over time

Studies Excluded from Consideration

• Confounded with inclusion of other nutrients^[1][2][3]

• Being language barrier^[4]