Antiviral medication is a type of prescription medicine that helps the body fight off harmful viruses. These drugs can ease symptoms and shorten the length of a viral infection, as well as lower the risk of getting or spreading viruses that cause herpes, HIV, and COVID-19. Antiviral drugs can also protect you from getting viral infections or spreading a virus to others. Most antivirals are oral drugs that you swallow, but they can also be received as eyedrops, inhaled powder, injection, IV, or topical ointments or creams. The treatment length varies depending on the antiviral drug and viral infection. Antiviral medications can treat certain viruses, putting an end to symptoms, and for people with chronic viral infections, antiviral drugs can stop the virus from multiplying and causing problems. Antiviral medications work by inhibiting molecular interactions and functions needed by the virus to produce new copies of itself, rather than killing the virus directly. The development of antivirals can be challenging because viruses are parasites that hijack host cell machinery, and care must be taken to select drug targets that interfere with viral replication while causing as little harm to healthy host cells as possible.