The nizonide 500mg (Nitazoxanide 500mg) is effective in treating and reducing worm infections caused by intestinal parasites. It works by interfering with the energy production of parasites, inhibiting their ability to survive and reproduce. Nizonide is particularly effective against protozoan and certain helminthic infections, including giardiasis, cryptosporidiosis, and various worm infections such as tapeworm and roundworm. Clinical studies have shown that it significantly reduces symptoms and parasite load, making it a valuable treatment option. However, the effectiveness can depend on the type of infection and the specific dosage, so medical consultation is recommended for optimal results.