Siberian ginseng is widely used to treat individuals with nervous exhaustion or anxiety due to chronic exposure to stress, or what is now termed ‘allostatic load situations’. The biochemical effects on stress responses observed in experimental and human studies provide a theoretical basis for this indication.
One placebo-controlled study conducted over 6 weeks investigated the effects of an ethanolic extract of Siberian ginseng (8 mL/day, equivalent to 4 g/day dried root). In the study, active treatment resulted in increased cortisol levels, which may be consistent with animal research suggesting a threshold of stress below which Siberian ginseng increases the stress response and above which it decreases the stress response.
Siberian ginseng is used to improve physical and mental responses during convalescence or fatigue states. Its ability to increase levels of noradrenaline, serotonin, adrenaline and cortisol provide a theoretical basis for its use in situations of fatigue. However, controlled studies are limited.
A randomised, double-blind, placebo-controlled trial of 300 mg/day (Eleutherococcus senticosus dry extract) for 8 weeks assessed health-related QOL scores in 20 elderly people. Improvements were observed in social functioning after 4 weeks of therapy but did not persist to the 8-week time point. It would appear that improvements diminish with continued use, which may help to explain the practice of giving Siberian ginseng for 6 weeks with a 2-week break before repeating.
A recent randomised placebo-controlled trial evaluated the effectiveness of Siberian ginseng in chronic fatigue syndrome (CFS). No significant improvements were demonstrated overall; however, sub-group analysis showed improvements in fatigue in CFS sufferers with less severe fatigue. Further studies are required to determine whether Siberian ginseng may be a useful therapeutic option in cases of mild to moderate fatigue.
Commission E approves the use of Siberian ginseng as a tonic in times of fatigue and debility, for declining capacity for work or concentration, and during convalescence. In practice, it is often used in low doses in cases of fatigue due to chronic stress.
Siberian ginseng extracts have been reported to provide better usage of glycogen and high-energy phosphorus compounds and improve the metabolism of lactic and pyruvic acids. Additionally, preliminary evidence of possible anabolic effects makes this herb a popular treatment among athletes in the belief that endurance, performance and power may improve with its use.
While initial animal studies showed promise, recent randomised, controlled clinical trials have produced inconsistent results in healthy individuals and athletes and a recent review concluded that only poorer quality trials have demonstrated benefit while well-designed trials have not shown significant improvement in endurance performance, cardiorespiratory fitness, or fat metabolism during exercise ranging in duration from 6 to 120 minutes.
In the mid 1980s, a Japanese controlled study conducted over 8 days showed that Siberian ginseng extract (2 mL twice daily) improved work capacity compared with placebo (23.3% vs 7.5%) in male athletes, owing to increased oxygen metabolism. Increased stamina was also seen.
More recently, a randomised, double-blind crossover trial using a lower dose of 1200 mg/day Siberian ginseng for 7 days reported that treatment did not alter steady-state substrate use or 10 km cycling performance time. Additionally, an 8-week, double-blind placebo-controlled study involving 20 experienced distance runners failed to detect significant changes to heart rate, oxygen consumption, expired minutevolume, respiratory exchange ratio, perceived exertion or serum lactate levels compared with placebo. Overall, both submaximal and maximal exercise performance was unchanged.
Clinical studies investigating whether anabolic effects observed in experimental studies occur in humans are lacking.
PREVENTION OF INFECTION
Due to the herb’s ability to directly and indirectly modulate immune responses, it is also used to increase resistance to infection. One double-blind study of 1000 Siberian factory workers supports this, reporting a 50% reduction in general illness and a 40% reduction in absenteeism over a 12-month period, following 30 days’ administration of Siberian ginseng.
More recently, a 6-month controlled trial in males and females with recurrent herpes infection found that Siberian ginseng (2 g/day) successfully reduced the frequency of infection by 50%.
In practice, Siberian ginseng is generally used as a preventative medicine, as administration during acute infections is widely thought to increase the severity of the illness, although this has not been borne out in controlled studies using Siberian ginseng in combination with other herbs. A small RCT demonstrated a significant reduction in the severity of familial Mediterranean fever in children using a combination of Siberian ginseng with licorice, andrographis and schisandra and a combination of Siberian ginseng with schisandra and rhodiola was found to expedite the recovery of patients with acute non-specific pneumonia.
Given the herb’s ability to increase levels of serotonin and noradrenaline in animal studies, a theoretical basis exists for the use of Siberian ginseng in depression.
In TCM, Siberian ginseng is used to encourage the smooth flow of Qi and blood when obstructed, particularly in the elderly, and is viewed as a general tonic. It is therefore used for a myriad of indications, usually in combination with other herbal medicines.
• 1-4 g/day dried root or equivalent preparations.
• Fluid extract (1:2): 2-8 mL/day (1 5-55 mL/week).
• Tincture (1:5): 10-15 mL/day.
• Extracts with standardised levels of eleutheroside E (>0.5 mg/mL) are recommended.
In practice, all ginsengs tend to be prescribed for no more than 1-3 months at a time with a break of at least several weeks before resuming treatment.