In vivo, assays demonstrated that the administration of various doses of FME, particularly in combination with MNZ over 7 days, resulted in a statistically significant reduction in the mean number and viability of Giardia cysts, serum level electrolytes (sodium and potassium), and the expression levels of interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF-α), nuclear factor κB p65 (NF-κB p65), and Toll-like receptor 4 (TLR-4) in mice with giardiasis (p < 0.001). Here, TLR4 is linked to giardiasis.