Effects of riboflavin on changes in pain threshold were investigated using the formalin test. The ends of the boxes depict the 25th and 75th percentiles, with a line at the median, while error bars extend to the 10th and 90th percentiles. During phase 1 of the formalin test, neither the vehicle-treated diabetic group nor the introduction of riboflavin showed significant changes in nociceptive behavior compared to the control group. In phase 2, the vehicle-treated diabetic group exhibited increased nociceptive behavior, while the addition of 25 mg or 50 mg of vitamin B2 significantly alleviated formalin-induced hyperalgesia. Significant differences compared to the control group (Normal) are indicated as *P < 0.05. Significant differences compared to the diabetic group (Diabetic) are indicated as #P < 0.05. n=8 animals per group.