Bottom Line: Panax ginseng does not improve strength and stamina. Whether it is helpful for erectile dysfunction or HIV treatment is still uncertain. There is no evidence that Panax ginseng can treat other medical conditions.
Although extensive research has been performed with Panax ginseng showing that it exhibits a wide range of biological activities, scientists are still not exactly sure how it works. The active ingredients in Panax ginseng are called ginsenosides. These substances show definite activity in the nervous systems of animals, with both stimulatory and inhibitory effects.
Certain ginsenosides are able to stimulate the immune system in mice. Ginsenosides may also have anti-cancer activity: when they are directly applied to melanoma cells in the laboratory, these cells stop their growth and replication. In addition, Panax ginseng can prevent some tumors in mice, including ovarian, lung, liver, and skin cancers. Some studies suggest that this effect may also occur in humans: in one study, Korean individuals who consumed Panax ginseng extract had a decreased risk of all types of cancer. There is still not strong evidence of this effect in humans, however.
Experiments have suggested that Panax ginseng may increase the production of nitric oxide in the heart, lung, and kidneys. Nitric oxide is a potent vasodilator - it is what helps reduce angina pain when patients take nitroglycerine tablets - so it may potentially work in the same way, but not much research has examined this use. In addition, studies in animals showed that Panax ginseng could lower blood cholesterol and triglyceride levels.
In humans, clinical trials suggest that Panax ginseng can reduce muscle injury and inflammation after exercise.
To treat angina Some laboratory studies show that Panax ginseng can increase the synthesis of nitric oxide, a vasodilator, but there is no proof from clinical trials that it can treat angina.
To treat diabetes No scientific evidence supports this use.
To maintain general health No scientific evidence supports this use. The long-term effects of Panax ginseng are not known.
To treat HIV and AIDS Research in humans shows that Panax ginseng stimulates certain aspects of the immune system, and although one small clinical trial supports this use, more research is necessary.
To stimulate the immune system Clinical trials support this use, although the long-term effects of Panax ginseng are still not known.
To improve blood clotting No scientific evidence supports this use.
To relieve pain No scientific evidence supports this use.
To treat sexual dysfunction One clinical trial supports the use of Panax ginseng for male erectile dysfunction.
To improve strength and stamina Several clinical trials do not support this use.
A group of researchers performed a systematic review of all the clinical trials that have used Panax ginseng in order to assess its overall effectiveness. Out of 16 well-designed clinical trials, they decided that no definitive conclusions could be drawn about how effective Panax ginseng is. This is partly because the studies used different types of Panax ginseng products, and partly because they looked at different uses for the herb.
HIV: A small clinical trial observed the effects of long-term intake of Panax ginseng in HIV positive patients who were starting zidovudine (AZT) therapy. Nine patients received ginseng (containing 5.4 mg of ginsenosides), while the other nine took a placebo pill. After two years, the group taking Panax ginseng maintained their CD4+ cell counts better and developed less resistance to AZT than the placebo group. Although these results are promising, this is a small study and the patients were not randomly assigned to their groups, indicating that larger and better-designed studies are needed to support this use.
Psychological well-being: The effect of Panax ginseng on psychological well-being in healthy young adults was studied in a randomized, controlled trial. Eighty-three subjects enrolled and were randomly assigned to one of three groups: taking 200 mg of Panax ginseng, taking 400 mg of Panax ginseng, or taking a placebo pill. After eight weeks, there was no major improvement in mood in the groups taking Panax ginseng compared to the placebo group. This study suggests that Panax ginseng does not alter mood in healthy young adults.
Immune stimulation: A randomized, controlled trial studied the ability of Panax ginseng extract to stimulate the immune system after vaccination for the common cold or flu. For four weeks before they were to receive cold or flu vaccines, 227 otherwise healthy volunteers were randomly assigned to take either ginseng extract or a placebo pill. They continued to take ginseng or placebo for another eight weeks. In this time, more volunteers taking the placebo developed a cold or the flu than did volunteers in the ginseng group. The volunteers taking ginseng also had a higher immune response to the vaccine, but they reported side effects such as insomnia, nausea, vomiting, and stomach pain. The results of this study are positive, but scientists need to know more about the short- and long-term effects of Panax ginseng on the human immune system.
Erectile dysfunction: The effectiveness of Panax ginseng for treating erectile dysfunction was studied in 45 men. This was a crossover study, meaning that the men took ginseng (900 mg three times a day) or a placebo for eight weeks, went off treatment for two weeks, then started on the other treatment for another eight weeks. This allows the researchers to see how the same man would fare on one treatment compared to the other. Scores of erectile function were higher in the ginseng group, as were reports of sexual performance. Sixty percent of the men in this trial thought that Panax ginseng greatly improved their symptoms. These results suggest that Panax (or Korean red) ginseng can be used as an effective alternative for treating erectile dysfunction.
Use of Panax ginseng should be stopped at least one week before surgery.
This product is regulated by the FDA as a dietary supplement. Unlike approved drugs, supplements are not required to be manufactured under specific standardized conditions. This product may not contain the labeled amount or may be contaminated. In addition, it may not have been tested for safety or effectiveness. Independent analysis of several brands has revealed considerable variation between ginseng manufacturers and products.
You have hormone-sensitive disease such as estrogen-dependent cancer (It is suspected, but not known, that Panax ginseng may have estrogen-like activity).
You are taking monoamine oxidase inhibitors (MAOIs) (If combined with MAOIs, Panax ginseng can cause manic-like symptoms).
You are taking insulin or sulfonylureas (Panax ginseng may increase their effect, causing a drop in blood sugar).
You are taking warfarin or other blood thinners (Panax ginseng may lessen their effects).
In one case report, a young man with no history of mental illness became manic following chronic consumption of 250 mg of Panax ginseng capsules three times a day. His symptoms resolved when he stopped taking the herb.
Derived from the root of the plant. Patients take this supplement to improve athletic performance, strength and stamina, and as an immunostimulant for diabetes, cancer, HIV/AIDS, and a variety of other conditions. It is also widely used as a 'Yang' tonic in chinese herbal formulas (2).The saponin glycosides, also known as ginsenosides or Panaxosides, are thought responsible for Panax ginseng's effects. Ginsenosides have both stimulatory and inhibitory effects on the CNS, alter cardiovascular tone, increase humoral and cellular-dependent immunity, and may inhibit the growth of cancer in vitro (3). Data from an epimediological study showed that ginseng improved survival and quality of life in breast cancer patients (20). However, ginseng may have estrogenic effects therefore, patients with hormone sensitive cancers should use it with caution. Panax ginseng is usually well tolerated, but insomnia, nausea, vomiting, and diarrhea have been reported (2). Panax ginseng may increase the hypoglycemic effect of insulin and sulfonylureas, and possibly antagonize the effects of anticoagulants. It may also interact with MAO inhibitors (10). It has been promoted in the treatment of erectile dysfunction, but current studies to support this claim are limited. Most Panax ginseng extracts are standardized to ginsenoside content, but independent laboratory analysis reveals considerable variation between manufacturers and products. Adequately designed clinical studies are needed to establish efficacy and optimal dosage levels. Panax ginseng should not be confused with American ginseng or Siberian ginseng, which have different medicinal properties.
Ginsenosides, also known as panaxosides, are thought responsible for Panax ginseng's activity, although the exact mechanism of action is unknown. Ginsenosides have stimulatory and inhibitory effects on the CNS. Animal studies suggest that ginsenoside Rb1 improves the release of acetylcholine and enhances postsynaptic uptake of choline. Ginsenosides compete for binding sites on GABAA and GABAB receptors in vitro. Rb1, Rb2, and Rc ginsenosides prolong hexobarbital sleeping time in mice and exhibit additional depressant effects on the CNS. Rg1 is associated with improved humoral and cell-mediated immune response and increases in T helper cells, T lymphocytes, and NK cells in mice. Anticancer activity has been shown in vitro for several ginsenosides. Differentiation of HL-60 (promyelocytic cells) is induced in Rh2- and Rh3-treated cells. Rh2 appears to cause arrest of B16-BL6 melanoma cells at the G1 phase along with suppression of cyclin-dependent-kinase-2. Studies with Rh2 show inhibited growth of human ovarian cancer xenografts and prolonged survival in nude mice (3). Use of Panax ginseng for chemoprevention reduces the incidence of chemically induced lung, liver, skin, and ovarian cancers in mice. Two case-controlled epidemiologic studies of Korean subjects suggest that Panax ginseng extract consumption reduces the incidence of all cancers (6)(7). Chemopreventive Panax ginseng also exhibits antioxidant activity. Panax ginseng may improve nitric oxide synthesis in endothelium of the heart, lung, kidneys, and in the corpus cavernosum (4). Ginsenosides administered intrathecally, intraperitoneally, or intracerebroventricularly produce analgesia against capsaicin-induced pain in mice (5). Panax ginseng may reduce muscle injury and inflammation following exercise in humans, as demonstrated by reduced levels of creatine kinase, beta-glucuronidase, and glucose-6-phosphate dehydrogenase (G6PDH) following oral Panax ginseng administration (8). In animal studies with rats and quails, Panax ginseng lowers total plasma cholesterol and triglyceride levels.
Common: Usually well tolerated. Reported: Dry mouth, tachycardia, nausea, vomiting, diarrhea, insomnia, and nervousness (2). Case report: A 26 year old male with no history of mental illness became manic following chronic consumption of 250 mg panax ginseng capsules three times a day. Symptoms, including irritability, insomnia, flight of ideas, and rapid speech, resolved following discontinuation of supplement (9).
Monoamine oxidase inhibitors (MAOIs): Panax ginseng may cause manic-like symptoms when combined with MAOIs. Insulin and sulfonylureas: Panax ginseng may increase the hypoglycemic effect of insulin and sulfonylureas. Anticoagulants: Panax ginseng may antagonize the effects of anticoagulants. (10)
Vogler BK, Pittler MH, Ernst E. The efficacy of ginseng. A systematic review of randomised clinical trials. Eur J Clin Pharmacol 1999;55:567-75. The authors reviewed all available randomized trials evaluating Asian Panax ginseng. A total of 57 trials were found in the literature, of which 41 were excluded (8 were not double-blind, 30 evaluated Panax ginseng in combination with other botanicals or supplements, 3 did not evaluate the extract of Panax ginseng root). Of the sixteen evaluable trials, no definitive conclusions regarding efficacy could be drawn. Seven studies evaluated Panax ginseng's effect on physical performance in healthy male volunteers, five reported cognitive effects, two studied immunomodulation, and individual studies reported glucose control in type II diabetics and severity and duration of type II herpes simplex infections. According to Vogler et al., the majority of studies reviewed were poorly designed or biased. Adverse events, including fatigue, sour stomach- and diarrhea, were reported in two of the sixteen studies. Various manufacturers and types of Panax ginseng extracts were used. Therefore, results of individual studies cannot be extrapolated to all Panax ginseng products. Additional, well-designed clinical research must be conducted to determine optimal use of Asian ginseng.
Cho YK, et al. Long-term intake of Korean red ginseng in HIV-1-infected patients: development of resistance mutation to zidovudine is delayed. Int Immunopharmacol 2001;1:1295-305. A small, prospective, evaluation of patients initiated on zidovudine (AZT) for HIV with or without the addition of Korean red ginseng (KRG) containing 5.4 mg ginsenosides. Change in CD4+, resistance to AZT, and viral load were primary outcomes measured. Each treatment group consisted of 9 patients and treatment continued for at least 24 months. Cho et al. suggest that addition of KRG to AZT therapy may maintain CD4+ cell counts and delay the development of resistance, but the effects of KRG when added to HAART remain unknown. Treatment allocation was not randomized. Also, due to the small sample size, further research is necessary to confirm these data.
Cardinal BJ, Engels HJ. Ginseng does not enhance psychological well-being in healthy, young adults: results of a double-blind, placebo-controlled, randomized clinical trial. J Am Diet Assoc 2001;101:655-60. A prospective, double-blind, placebo-controlled, randomized clinical trial evaluating 83 adults randomly assigned to one of three experimental conditions: placebo, 200 mg G115 Panax ginseng, or 400 mg G115 Panax ginseng. Each participant was given a 60-day allotment of their respective supplement along with written instructions about the proper intake and storage of the capsules during the 8-week study period. Primary outcomes were change in mood and total mood disturbance as measured by Profile of Mood Status (POMS). Following one month of Panax ginseng supplementation, there was no significant improvement in affect or total mood disturbance as compared to placebo (P > .016). No significant adverse effects are reported. This study suggests that Panax ginseng does not alter mood in health subjects.
Scaglione F, et al. Efficacy and safety of the standardized ginseng extract G115 for potentiating vaccination against common cold and-or influenza syndrome. Drugs Exp Clin Res 1996;22:65-72. A prospective, randomized, double-blind, placebo-controlled evaluation of G115 ginseng extract on immune response following administration of the influenza vaccine and rate of common cold and flu infections. Patients were randomized to 2 capsules of placebo (n=113) or G115 ginseng extract (n=114) once daily initiated 4 weeks prior to vaccination and continued for a total of 12 weeks. Between weeks 4 and 12, 37% of patients on placebo developed infections consistent with the common cold or influenza versus 13% for those receiving G115. Antibody titers and NK cell activity were significantly higher for the active treatment arm as compared to placebo, 200 versus 148 and 43.6% versus 27% respectively. Adverse events for the G115 group included insomnia, nausea, vomiting, and epigastric pain. The authors suggest that G115 improve immune response and decreases the frequency of the common cold and/or influenza. It is unknown if effects persist following discontinuation of G115 as patients were not monitored past 12 weeks. Additional research is necessary to understand short- and long-term effects of ginseng extract supplementation on the immune system.
