Safety Analysis of Panax Ginseng in Randomized Clinical Trials: A Systematic Review

Background: Panax ginseng C.A. Meyer is one of the most frequently used herbs in the world. The roots of Panax ginseng have been used as a traditional tonic and medicine for thousands of years in Korea and China. Today, ginseng root is used as a dietary supplement and complementary medicine and for adjuvant therapeutics worldwide. The efficacy of ginseng has been studied in a wide range of basic research and clinical studies. However, it has been reported that the results from clinical studies are conflicting, and they depend on the parameters of the protocol design including the conditions of the participants and the types of ginseng used such as red ginseng, white ginseng, fermented ginseng and cultured ginseng. Meanwhile, in addition to clinical efficacy, the safety of ginseng is a highly important matter for customers. With globally increasing demand for Panax ginseng as a dietary supplement or complementary medicine, it is necessary to provide information on its safe use to customers to improve their health conditions. Although the safety of Panax ginseng in pre-clinical studies is well known, the evaluation of safety in clinical studies has so far been insufficient. This systematic review was conducted to assess the safety of ginseng in randomized controlled clinical trials (RCT) over the last 10 years. We chose the last 10 years because many clinical trials have been conducted in the past 10 years, and it will help to understand the recent trends in RCTs of ginseng. Methods: Articles on ginseng studies were searched with keywords in MEDLINE and four other Korean online database sites. Studies with ginseng as a monopreparation were selected while studies with single administration, preparations combined with other herbs or drug combinations were excluded from the selected studies. Data from the selected studies meeting the criteria were extracted and reviewed in terms of study design, condition and number of participants, type of ginseng, dosage, duration, main results, adverse events and adverse reactions. Results: Forty-four studies met the selection criteria. These studies covered the efficacy of ginseng in areas such as cardiovascular function, glucose metabolism, sexual function, anti-oxidation, anti-fatigue and psychomotor function. Twenty-nine studies showed positive results while fifteen studies showed no effect. Sixteen studies reported adverse events while five studies had no adverse events. Twenty-three studies did not mention any adverse events. The main adverse events of ginseng reported were general symptoms such as hot flushes, insomnia and dyspepsia with no significant difference in frequency and symptoms between the ginseng and placebo groups. The symptoms were mild and temporary with no serious or severe adverse events. Conclusion: Panax ginseng showed a very safe profile in a limited number of RCTs with a small number of participants with various conditions ranging from healthy participants to patients with symptoms. However, to increase the usefulness and lower the health risk of Panax ginseng to customers, clinical trials on a larger scale and with a higher standard are necessary to define its efficacy and safety as a dietary supplement or complementary medicine.