Hydroxychloroquine 200 mg is a medication commonly used to treat conditions like malaria, lupus, and rheumatoid arthritis. It works by interfering with the growth of parasites in the red blood cells. Hydroxychloroquine 100 mg, a lower dosage, serves the same purposes but with a reduced potency. Both variants have been explored for their potential in treating COVID-19, but their effectiveness remains controversial and is not recommended as a primary treatment. It's crucial to consult a healthcare professional before using hydroxychloroquine or any medication, as it can have side effects and interactions with other drugs.