Volunteers will be divided into 4 groups which are mulberry leaf extract 6 mg capsule, mulberry leaf extract 12 mg capsule, mulberry leaf extract 18 mg capsule, and placebo capsule group. They will be tested blood glucose levels (taken from the fingertips) before starting. Then, they will take 1 capsule of the sample one time. After taking the sample for 30 minutes, they will take 50 g of sucrose in 250 ml of water in 5 minutes. Then, they will be tested blood glucose levels (taken from the fingertips) at 30, 60, 90, and 120 minutes.

Inclusion Criteria:

• Age 18-60 years
• No diabetes mellitus
• Have blood glucose less than 126 mg/dL
• Wiling to attend the study

Exclusion Criteria:

• Take steroids, psychiatric medicine, thiazide diuretic medicine, and beta blocker medicine within 2 weeks before starting of the study
• Take dietary supplement, herbal substance, and weight-loss medicine within 2 weeks before starting of the study
• Uncontrolled diseases
• History of gastrointestinal tract surgery
• Liver and Kidney diseases
• Pregnancy and lactation