Objective: The aim of this study is to evaluate the antidiabetic effect and safety of Yukmijihwang-hwan for Type 2 Diabetes without complications by systemic review and meta-analysis.

Methods: A systemic search of the 9 electronic databases will be performed to identify eligible studies : Search terms will be based on "Type 2 Diabetes" for participants, and "Yukmijihwang-tang" or "Liuwei dihuang tang" for interventions. Data extraction and evaluationg risk of bias(RoB) were performed by two individual authors, and if there are disagreement between two researchers, it will be resolved through the intervention of a third researcher.

Results:
1. Total 30 RCTs were included for systematic review. 28 were published within last 10 years. All included literatures were published in China.

2. Average number of patients were 98.97±37.52, and 9 studies were conducted within 80 to 100 patients. Average age was mentioned in 29 studies, and 19 studies with average patient age of 50s were the most. Average period of morbidity was mentioned in 22 studies, and 6 studies with average duration of 5 to 6 years were the most.

3. The intervention applied in most studies was combined treatment with Yukmijihwang-hwan and oral hypoglycemic agents. 28 studies used pill-type Yukmijihwang-hwan, while Yukmijihwang decoction was used in 2 studies. Regarding the number of doses, in 19 studies, it was taken 3 times a day. The number of studies that set the dose to 3 g per time was the most with 12 studies. 12 studies with treatment period of 12 weeks or longer were the most.

4. Yukmijihwang-hwan improves blood sugar, insulin resistance, and beta-cell function of the pancreas. It also enhances the effect of drug treatment (oral hypoglycemic agents, insulin, and GLP-1 agonists).

5. Adverse reactions were found in 5 studies that intervened with the combination treatment of Yukmijihwanghwan+oral hypoglycemic agents, and the main adverse reactions were digestive symptoms(abdominal bloating, bowel sound, diarrhea, constipation), decreased appetite, and cardiovascular symptoms(increasing blood pressure, arrhythmia, hot flushes).

Conclusion: As a result, for improving glucose level, insulin resistance, and beta-cell function of the pancreas of patients with type 2 diabetes without complications, Yukmijihwang-hwan should be considered. However, the quality of the included studies was generally low. Also, heterogeneity between included studies was high. Therefore, these limitations need to be considered when interpreting the results of this study. Further studies are needed to supply the efficacy and safety of Yukmijihwang-hwan for type 2 diabetes mellitus.