Pooled estimates showed that the use of berberine could significantly reduce the concentration level of C-reactive protein (CRP) [standardized mean difference (SMD) = − 1.54, 95% confidence intervals (CI) − 1.86, − 1.22, p < 0.05], tumor necrosis factor-α (TNF-α) [SMD = − 1.02, 95% CI − 1.27, − 0.77, p < 0.05], and interleukin 6 (IL-6) [SMD = − 1.17, 95% CI − 1.53, − 0.81, p < 0.05] among patients with MetS and related disorders. Here, TNF is linked to metabolic syndrome.