Acetylcysteine Injection is used primarily as a mucolytic agent to help break down and loosen thick mucus in conditions such as chronic obstructive pulmonary disease (COPD) and cystic fibrosis. It is also used as an antidote for acetaminophen (paracetamol) overdose to protect the liver from damage. The medication works by replenishing glutathione levels, which helps neutralize harmful substances and reduce oxidative stress. Administered intravenously, common side effects may include nausea, rash, and potential allergic reactions. Regular monitoring by a healthcare provider is essential during treatment. Always follow the prescribed dosage and report any unusual symptoms or side effects to your healthcare team.