Schisandra Clinical Evidence

Panossian A and Wagner H. Stimulating effect of adaptogens: An overview with particular reference to their efficacy following single dose administration. 2005;19:819-838.

Topic:
What are the effects of Rhodiola rosea, Schizandra chinensis and Eleutherococus senticocus when taken in a single dose?

Background:
Conventional stimulants can be addictive, disrupt sleep and cause rebound fatigue. Can adaptogens produce improvements in physical and mental performance without these damaging side effects?

Study Type:
Review paper

Dosage:
Varied by study

Results:
The authors found that:

• All three adaptogens function as mild stimulants and, unlike many other stimulants, have no harmful side effects.
• Rhodiola is the most active of the three substances, taking effect 30 minutes after administration, with beneficial effects lasting for at least 4 hours.
• Rhodiola improves short-term memory and learning, and increases mental working capacity, efficacy (decreased number of errors) and speed of information processing.
• Schizandra also improves mental efficacy and increases physical stamina, especially in fatigued subjects. In one study, working capacity was increased by 222% when compared to the control group.

Conclusion:
R. rosea, S. chinensis and E. senticocus exhibit a harmless, ‘adaptogen-type’ stimulating effect on humans leading to improvements in mental performance and learning efficacy after single dose administration.

Panossian A and Wikman G. Evidence-based efficacy of adaptogens in fatigue, and molecular mechanisms related to their stress-protective activity. 2009 Sep;4(3):198-219.

Topic:
What is the evidence for the use of adaptogens to treat fatigue and how are those effects achieved at the molecular level?

Background:
The authors define an adaptogen as an herb that increases tolerance of mental fatigue and that improves attention and mental endurance under stress. In a previous study, 10 days of treatment with schizandra helped patients with astheno-depressive syndrome (marked by fatigue, inactivity and mild depression) make a full recovery.

Study Type:
Review paper

Dosage:
Varied by study

Results:
The authors confirm that there is solid scientific evidence supporting the use of schisandra for people suffering from mental exhaustion. They also outline the molecular mechanism by adaptogens work: by mimicking stress and thereby up-regulating the stress sensor protein Hsp70. This protein protects cells from heat stress and toxic chemicals and thereby helps cells survive. Hsp 70 interacts with a gene that inhibits the production of nitric oxide (a compound that blocks the release of stored energy as ATP from red blood cells) and regulates glucocorticoid receptors (the binding places for the stress hormone cortisol). Through these actions, Hsp 70 affects levels of cortisol, nitric oxide, and ATP in the bloodstream. The result is enhanced mental and physical performance.

Conclusion:
Good scientific evidence has been documented in trials in which Schiasandra chinesis… increased endurance and mental performance in patients with mild fatigue and weakness.

Like ginkgo, schisandra also optimizes norepinephrine and dopamine levels, increasing the brain’s ability to maintain focus and improving mood.

As an adaptogen, schisandra normalizes or balances pathways in the body to bring about greater physiological stability in the face of stress that might otherwise cause fatigue. For example, it balances levels of stress hormones such as cortisol, maintains immune function, and stabilizes blood sugar levels.

Schisandra increases physical working capacity through several modes. It modulates levels of nitric oxide and cortisol in the blood, thus affecting the central nervous system. It excites the adrenergic system, and leads to deeper breathing with increases in both the consumption of oxygen and the production of carbon dioxide. And it supports the functional activity of the adrenal glands, higher energy metabolism, and better function of the cardiovascular system.