Lisinopril (also found under the brand name Zestril) is a drug commonly used to treat high blood pressure. It’s in a class of drugs called angiotensin-converting enzyme (ACE) inhibitors. Angiotensin is a chemical in your body that narrows blood vessels. Along with lowering blood pressure, lisinopril has also been used to help treat other conditions, like heart failure and kidney disease. Here’s more on what you need to know about lisinopril, its primary uses, and what side effects to be aware of before taking the drug.