Ginseng Supplements Review
Initial Posting: 3/14/14 Updated: 2/27/18
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What It Is:
Ginseng is the dried root of one of several species of the Araliaceae family of herbs. The most commonly used type is Asian ginseng (Panax ginseng C.A., Meyer), often sold as Panax, Chinese, or Korean ginseng.
Closely related to Asian ginseng is American ginseng (Panax quinquefolius L.), which interestingly, is more widely used in China than in America and is sometimes preferred for its milder effects. A large amount of American ginseng is grown in Wisconsin and sold as Wisconsin ginseng.
So-called "Siberian" or "Russian" ginseng, more properly Eleutherococcus senticosus (eleuthero) Rupr. ex Maxim, is only distantly related to true ginseng, and does not contain the same active compounds. For this reason, Eleutherococcus products were not included in this Review. Eleuthero is also considered weaker in action and is a less expensive ingredient.
When ginseng root is left mostly unprocessed it is called "white ginseng." "Red ginseng" refers to Asian ginseng root when it has been steamed and dried. According to traditional Chinese medicine, these various forms of ginseng have different properties. However, the current scientific evidence is not advanced enough to determine these differences in an objective way.
Ginseng-containing foods and dietary supplements are typically made from a powder or extract of "white" or "red" ginseng root.
What It Does:
Ginseng is widely used in the United States with the belief that it will improve overall energy and vitality, particularly during times of fatigue or stress. While there is little meaningful scientific evidence to support an energy boosting effect in the general population, a placebo-controlled study found ginseng to reduce self-reported cancer-related fatigue -- which can occur even after cancer is successfully treated. In the study, people taking 2,000 mg of American ginseng root powder daily for 8 weeks showed a statistically significant improvement in energy (of about 10 points on a 100-point self-reported fatigue scale) compared to those taking placebo, with no difference in side effects. Fatigue was most improved among those actively being treated for cancer, as opposed to those treated in the past -- with significant improvements occurring earlier in this subgroup (within just 4 weeks of ginseng use) (Barton, JNCI 2013). The researchers point out that good treatments for cancer-related fatigue are not available. Although preliminary (non-human) data suggests that ginseng does not interfere with the activity of many common chemotherapeutic agents (tamoxifen, doxorubicin, cyclophosphamide, paclitaxel, 5-fluorouracil, and methotrexate), these interactions have not been well studied. Consequently, the researchers suggest that it would be reasonable for a cancer survivor to try American ginseng for related fatigue. The ginseng studied was from Wisconsin, contained 3% ginsenosides, and was taken daily as two 500 mg capsules at breakfast and again at noon. The study was preceded by a smaller pilot study which also showed benefit, although the product at that time contained 5% ginsenosides.
There is some preliminary evidence that American ginseng and Korean Red ginseng (from Panax ginseng) may reduce blood sugar levels in people with diabetes (see Encyclopedia article about Diabetes). A study in Canada among 24 older men and women with type 2 diabetes (most of whom were taking antidiabetes medication) found that 1 gram of American ginseng extract (9.67% ginsenosides) taken three times daily (40 minutes before each meal) for two months modestly reduced fasting blood glucose (- 0.71 mmol/L), HbA1c (- 0.29%), and systolic blood pressure (- 5.6 mmHg) compared to placebo. The total daily dose of extract (CNT 2000, Chai-Na-Ta Corp., Langley, BC) was 3 grams, which provided 290 mg of ginsenosides (Vuksan, Eur J Nutr 2018).
There is also evidence that a hydrolyzed Panax ginseng extract can improve fasting and post-prandial (after-eating) glucose levels, based on a study in which adults with impaired fasting glucose were given 480 mg of hydrolyzed Panax ginsengextract (1.7% ginsenosides) after breakfast and again after dinner (providing a total daily dose of about 16 mg ginsenosides and 6 mg of compound K). After 8 weeks, those taking the extract had significantly lower plasma glucose levels after fasting and after ingesting a glucose drink compared to those taking a placebo. There was no significant change in insulin secretion and no adverse effects were reported (Park, J Ginseng Res 2014). Note: The hydrolyzed ginseng used in this study, conducted in South Korea, does not appear to be available in the U.S. Be aware, however, that research has also shown that ordinary Panax ginseng (non-hydrolyzed) might raise blood sugar levels and be harmful in diabetes (See Concerns and Cautions).
A study in Korea among men with metabolic syndrome who took 3 grams of red ginseng high in ginsenosides (about 17%) daily for one month found there was no significant improvement in most measures of health (including systolic blood pressure, BMI, fasting blood sugar, insulin and cholesterol levels), compared to placebo. However, there were small increases in blood levels of total testosterone (from 396 to 418 ng/mL ) and IGF-1 (from 145 to 167 ng/mL) -- hormones which can be low in men with metabolic syndrome — as well as a small decrease (5 mmHg) in diastolic blood pressure (Jung, Complement Ther Med 2016).
Studies using an American ginseng proprietary extract (Cold-FX) suggest that it might help prevent the common cold. However, this was not a standard ginseng extract as it contained a very high concentration of polysaccharides. There is preliminary evidence that Asian ginseng may also help reduce the chance of colds and flus.
A concentrated extract of Korean Red ginseng showed promise in improving symptoms of attention deficit-hyperactivity disorder (ADHD) without adverse effects in children ages 6 to 15. In the 8-week, placebo-controlled study, children with ADHD were given 1 gram of extract (consumed as a liquid from a pouch) twice a day (Ko, J Child Adolesc Psychopharmacol 2014). Hyperactivity scores (means) decreased significantly more among those given ginseng (from 3.09 to 1.76) than placebo (3.81 to 3.03). Inattention scores also decreased significantly in the ginseng group (from 6.39 to 4.03), although not significantly more than in the placebo group (5.70 to 4.57). The ginseng group also had a greater decrease in brain wave activity (TBR) indicative ADHD, but not in levels of stress hormones (cortisol and DHEA). Details were not reported about the chemical composition of extract, which was provided by the Korea Ginseng Corporation which funded the study, but without intervention, and which appears to sell a similar liquid pouch product but in a larger dose (3 grams per pouch). A pilot study using American ginseng combined with Gingko biloba also indicated improvement in symptoms of ADHD (Lyon, J Psychiatry Neurosci 2001).
Two studies enrolling a total of 135 men support the use of Panax ginseng for enhancing sexual function in men. One of these studies was a 3-month double-blind, placebo-controlled trial that evaluated the effects of Korean red ginseng (steamed and heat-dried Panax ginseng) in 90 men with erectile dysfunction. Participants received either red ginseng at a dose of 1,800 mg daily, the drug trazodone (an antidepressant with marginal effects on erectile dysfunction) or placebo. The results indicated that red ginseng worked better than both the placebo and trazodone treatments (Choi, Int J Impot Res 1995). Contrary to some reports, ginseng does not appear to affect estrogen or testosterone levels or mimic their effects.
Other studies have looked at the role of even higher doses of red ginseng in sexual function. One study in Brazil examined the effects of 3,000 mg of red Korean ginseng versus placebo in men with mild to moderate erectile dysfunction. Sixty-six percent of the men using ginseng saw an improvement in their erections while there was no significant improvement among men receiving placebo (de Andrade, Asian J. Anrdol. 2007).
Korean red ginseng may also improve sexual arousal in menopausal women. A double blind, placebo-controlled cross-over study in Korea comparing the effects of 3,000 mg of red ginseng to placebo in 28 women (average age 51 years old) found a significant improvement in arousal. No severe side effects were reported although 2 women experienced vaginal bleeding while taking the ginseng product (Oh, J Sex Med 2010).
A study among 80 women in Korea with cold hypersensitivity in the hands and feet (CHHF -- which can include Raynaud's phenomenon) found those who took six capsules of red Korean ginseng twice daily (a total daily dose of 6,000 mg of ginseng containing 3.4% ginsenosides) for two months had significantly higher skin temperature in hands and feet, less discomfort, and improved response to cold exposure compared to those who took a placebo (Park, J Ethnopharmacol 2014).
Other uses of various forms of ginseng with weak or contradictory supporting evidence include enhancing mental function and general well being (Panax ginseng) and stimulating the immune system (Panax ginseng). (See the Ginseng article in the Encyclopedia for more information about uses.)
Plant chemicals called ginsenosides are hypothesized to play a role in ginseng's biological activity. They are considered "marker" compounds for ginseng — that is, their presence (or absence) and their chemical profiles can indicate the type and quality of ginseng in a product. It is strongly suspected that different ginsenosides have different effects, but not enough is known to make definitive statements about which ginsenosides are most important for a specific proposed use of ginseng.
Quality Concerns and What CL Tested for:
Quality and quantity of ginseng: Ginseng is expected to contain specific minimum amounts of ginsenosides. Levels of these are sometimes advertised on product packaging. Previous testing by ConsumerLab.com has shown that not all products meet the standards or their claims — either because too little ginseng is used or it is of poor quality.
Pesticides and heavy metals: ConsumerLab.com has found pesticide and heavy-metal contamination in the past in ginseng products in the U.S. and Japan. The pesticides pentachloronitrobenzene (known as quintozene or PCNB) and lindane are not allowed for use on U.S. food crops because they are possible carcinogens that may also be toxic to the liver and kidneys and may impair oxygen transport in the blood. Another potentially carcinogenic pesticide, hexachlorobenzene, has been banned from most food-crop use throughout the world.
Ability to Break Apart (Disintegrate): Supplements sold as tablets and caplets (except enteric coated, chewable and time-release formulas) must be able to break apart properly in the stomach in order to release their ingredients. From time to time, ConsumerLab.com has found supplements that do not fully break apart.
Because no government agency is responsible for routinely testing ginseng supplements for their contents or quality, ConsumerLab.com independently evaluated several leading ginseng products to determine whether they contained the type and amount of ginseng stated on their labels and were free of contamination with specific pesticides and heavy metals (cadmium, arsenic, lead and mercury). Any tablets or caplets were also tested to be sure that they could disintegrate ("break-apart") properly.