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licorice root plant

© 2018 Steven Foster

A licorice root monograph for the home

Latin Name: Glycyrrhiza glabra, Glycyrrhiza uralensis

Common Names: licorice root, licorice, liquorice, sweet root, gan cao, gan-zao, Chinese licorice

This licorice root monograph provides basic information about licorice root—common names, usefulness and safety, and resources for more information.


Licorice Root Basics

  • Most licorice root grows in Greece, Turkey, and Asia. Anise oil is often used instead of licorice root to flavor licorice candy.
  • Centuries ago, licorice root was used in Greece, China, and Egypt for stomach inflammation and upper respiratory problems. Licorice root also has been used as a sweetener.
  • Today, people use licorice root as a dietary supplement for digestive problems, menopausal symptoms, cough, and bacterial and viral infections. People also use it as a shampoo.
  • Licorice is harvested from the plants’ roots and underground stems. Licorice supplements are available as capsules, tablets, and liquid extracts.

Licorice Root in Health Research

  • A number of studies of licorice root in people have been published, but not enough to support the use for any specific health condition.

Licorice Root Research Summary

  • Glycyrrhizin—a compound found in licorice root—has been tested in a few clinical trials in hepatitis C patients, but there’s currently not enough evidence to determine if it’s helpful. Laboratory studies done in Japan (where an injectable glycyrrhizin compound is used in people with chronic hepatitis C who do not respond to conventional treatment) suggest that glycyrrhizin may have some effect against hepatitis C.
  • There’s some evidence that topical licorice extract may improve skin rash symptoms, such as redness, swelling, and itching.
  • A Finnish study of mothers and their young children suggested that eating a lot of actual licorice root during pregnancy may harm a child’s developing brain, leading to reasoning and behavioral issues, such as attention problems, rule-breaking, and aggression.
  • Studies of licorice root extracts in people for cavities, mouth ulcers, and oral yeast infections have returned mixed results.

Licorice Root Safety

  • In large amounts and with long-term use, licorice root can cause high blood pressure and low potassium levels, which could lead to heart and muscle problems. Some side effects are thought to be due to a chemical called glycyrrhizic acid. Licorice that has had this chemical removed (called DGL for deglycyrrhizinated licorice) may not have the same degree of side effects.
  • Taking licorice root containing glycyrrhizinic acid with medications that reduce potassium levels such as diuretics might be bad for your heart.
  • Pregnant women should avoid using licorice root as a supplement or consuming large amounts of it as food.

Licorice Root References


PubMed Articles About

Source: National Center for Biotechnology Information (NCBI)[Internet]. Bethesda (MD): National Library of Medicine (US), National Center for Biotechnology Information; [1988] – [cited 2018 Apr 5]. Available from:

Wang, CX., Wu, D., Yang, PP., Wu, QH., (2020) [Efficacy and safety of non-vitamin K antagonist versus vitamin K antagonist oral anticoagulants in the prevention and treatment of thrombotic disease in active cancer patients: a systematic review and meta-analysis of randomized controlled trials].

We aimed to compare the efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOAC) and vitamin K antagonist (VKA) in the prevention and treatment of thrombotic diseases in patients with active cancer. To find randomized controlled trials (RCT) in which NOACs were compared VKAs in active cancer, we searched the electronic databases (PubMed, Web of Science and Clinical Trials) up to May 2019 and and languages restricted to Chinese and English. According to the screening strategy, two researchers independently screened and extracted literature, evaluated the quality of literature, the suitability of collected cross study data for analysis, and tested the heterogeneity. The relative risk () and 95% confidence interval (95%) of major bleeding, clinically related non-major bleeding, VTE, stroke and all-cause mortality in active cancer patients with VTE, active cancer patients with non-valvular atrial fibrillation (NVAF) was calculated and the results were compared between NOAC with VKA. A total of 9 RCTs were included, including 5 cancers with VTE (5/9) and 4 cancers with NVAF (4/9). A total of 5 867 patients were included. After excluding 1 818 (30.99%) patients with cancer history, 4 049 (68.86%) patients with active cancer were statistically analyzed. Among them, 2 278 (56.26%) received NOAC treatment, 1 771 patients (43.74%) received VKA treatment. The quality of the included documents was high (all scores were>5 points), and the data of each included document could be summarized and analyzed (>0.05). The heterogeneity of main outcome events was very low ( = 0). In VTE patients with active cancer, NOACs were more effective in reducing recurrence of VTE (=0.55, 95% 0.36 -0.84; 0.005) and clinically related non-major bleeding (=0.77, 95% 0.60 -0.98; 0.03) than VKAs. In NVAF patients with active cancer, efficacy of NOACs and VKAs was similar in terms of reducing VTE, stroke, clinically related non-major bleeding, major bleeding and all-cause mortality events (>0.05). For patients with active cancer accompanied by VTE, NOAC may has more advantages in efficacy and safety compared to VKA in the prevention and treatment of thrombotic diseases.

Zhang, ZD., Liu, H., Lyu, J., Yu, DD., Sun, MH., (2020) [Systematic review and Meta-analysis of efficacy and safety of Xiangsha Yangwei Pills in treatment of chronic gastritis].

To systematically evaluate the efficacy and safety of Xiangsha Yangwei Pills in the treatment of chronic gastritis. Compu-ter retrieval was performed for Cochrane Library, Medline, EMbase, China Knowledge Network Database(CNKI), China Biomedical Literature Service System(SinoMed), Chongqing Weipu Chinese Science and Technology Journal Database(VIP) and WanFang Database(WanFang) randomized controlled trials about Xiangsha Yangwei Pills combined with Western medicine in the treatment of chro-nic gastritis. The retrieval time ranged from the establishment of the library to April 26, 2019. Meta-analysis was performed by RevMan 5.3 software after two independent researchers conducted literature screening, data extraction and quality evaluation according to inclusion and exclusion criteria. A total of 1 720 patients were enrolled in 18 RCT. According to the classification of chronic gastritis, they were divided into three subgroups: chronic gastritis, chronic atrophic gastritis and chronic superficial gastritis. The results of Meta-ana-lysis showed that the efficacy of Xiangsha Yangwei Pills combined with Western medicine in treating chronic gastritis was higher than that of Western medicine. As for the recurrence rate, Xiangsha Yangwei Pills combined with Western medicine was lower than Western medicine. And there was no statistical difference about helicobacter pylori(Hp) eradication rate between Xiangsha Yangwei Pills combined with Western medicine as well as Western medicine. In terms of the incidence of adverse reactions, Xiangsha Yangwei Pills combined with Western medicine was lower than Western medicine, and no serious adverse reaction was reported. The results of this systematic review showed that compared with the conventional Western medicine group, Xiangsha Yangwei Pills combined with Western medicine can significantly alleviate clinical symptoms of chronic gastritis, with fewer adverse reactions. However, due to the low methodological quality of the included studies and the reliability of the impact conclusions, high-quality multi-center, large-sample, randomized, double-blind controlled trials are needed for validation.

Clifford, T., Jeffries, O., Stevenson, EJ., Davies, KAB., (2020) The effects of vitamin C and E on exercise-induced physiological adaptations: a systematic review and Meta-analysis of randomized controlled trials.

We conducted a systematic review and meta-analysis of randomized controlled trials examining the effect of vitamin C and/or E on exercise-induced training adaptations. Medline, Embase and SPORTDiscus databases were searched for articles from inception until June 2019. Inclusion criteria was studies in adult humans where vitamin C and/or E had to be consumed alongside a supervised exercise training program of ≥4 weeks. Nine trials were included in the analysis of aerobic exercise adaptations and nine for resistance training (RT) adaptations. Vitamin C and/or E did not attenuate aerobic exercise induced improvements in maximal aerobic capacity (O (SMD -0.14, 95% CI: -0.43 to 0.15,  = 0.35) or endurance performance (SMD -0.01, 95% CI: -0.38 to 0.36,  = 0.97). There were also no effects of these supplements on lean mass and muscle strength following RT (SMD -0.07, 95% CI: -0.36 to 0.23,  = 0.67) and (SMD -0.15, 95% CI: -0.16 to 0.46,  = 0.35), respectively. There was also no influence of age on any of these outcomes ( > 0.05). These findings suggest that vitamin C and/or E does not inhibit exercise-induced changes in physiological function. Studies with larger sample sizes and adequate power are still required.

Chen, G., Chen, Y., Chen, Z., Gao, S., Zhang, P., Zhang, H., Huang, Y., Lin, Y., Wei, L., (2021) Sanao decoction for asthma: Protocol of a systematic review.

Asthma is a chronic inflammatory disease characterized by recurrent attacks of breathlessness and wheezing, which often worsen at night or in the early morning and vary from person to person in severity and frequency. Sanao decoction (SAD), as a traditional Chinese medicine compound, has a long history of clinical application in the treatment of respiratory diseases. Whereas neither systematic nor meta-analysis of randomized controlled articles explain the efficacy of SAD in treating asthma. Therefore, we provide a protocol to evaluate the efficacy and safety of SAD for asthma.