Metronidazole 400mg is a prescription antibiotic that is widely used in the UK to treat a variety of bacterial and parasitic illnesses, including dental infections, bacterial vaginosis, pelvic infections, and gastrointestinal conditions like giardiasis. It works by stopping the growth of infection-causing microorganisms, helping the body recover effectively. Metronidazole is rarely accessible over the counter in the United Kingdom and must be prescribed by a certified healthcare professional following a suitable diagnosis. To avoid resistance and infection recurrence, patients should carefully follow the specified dosage and complete the entire term of treatment.