Lisinopril is a blood pressure and heart medication taken by mouth, usually once a day. It is used alone or with other drugs for high blood pressure in adults and children 6 and older, in combination for heart failure, and to improve survival after a heart attack (National Library of Medicine / MedlinePlus, 2021-02-15). Most people who notice anything notice dizziness or a dry, tickly cough.
This guide covers what the drug does, what side effects look like day to day, which ones mean picking up the phone or heading to an emergency room, and what to ask at your next visit. Your prescriber decides your dose and any changes to it.
What Lisinopril Does
Your body makes a chemical signal that tells blood vessels to tighten. Lisinopril turns that signal down. With less of it circulating, the vessels sit more relaxed and wider, so blood moves through them more smoothly and your heart pushes against less resistance with each beat (National Library of Medicine / MedlinePlus, 2021-02-15). Think of easing your grip on a garden hose rather than forcing more water through a pinched one.
The drug class is angiotensin-converting enzyme inhibitors, usually shortened to ACE inhibitors. For high blood pressure, lisinopril is usually a first-line treatment (Wikipedia, citing AHFS Drug Information 2018).
It comes as a tablet and as a liquid solution, and is usually taken once a day; prescribers generally begin with a low amount and increase gradually, so the number on your bottle is their decision and may change (National Library of Medicine / MedlinePlus, 2021-02-15). It stays active long enough for once-daily dosing — its elimination half-life is about 12 hours, and it leaves the body unchanged in the urine (Wikipedia, undated).
Don't expect an overnight change. The full effect may take up to four weeks (Wikipedia, citing AHFS Drug Information 2018). It controls the condition rather than permanently resolving it, which is why MedlinePlus advises continuing it even when you feel well. Expect ongoing checks too: your blood pressure should be measured regularly to see how you are responding, and your doctor may order lab tests, partly because high potassium often causes no symptoms at all and only shows up in bloodwork (National Library of Medicine / MedlinePlus, 2021-02-15; GoodRx Health, 2025-03-04).
Common Side Effects
These are things people actually notice. Report any of them to your prescriber if they are severe or don't go away (National Library of Medicine / MedlinePlus, 2021-02-15).
Dizziness — lightheaded feeling, often soon after starting or after an increase; usually improves as the body adjusts (GoodRx Health, 2025-03-04).
Dry cough — a tickling or scratching in the throat, often starting within the first weeks or months, though it can begin at any time (GoodRx Health, 2025-03-04).
Headache — typically mild and more noticeable early on.
Excessive tiredness or weakness — low energy that may ease over several weeks.
Nausea or diarrhea — stomach upset that is usually short-lived.
Sneezing or runny nose — cold-like, without being a cold.
Rash — any new skin rash is worth reporting.
Decrease in sexual ability — uncomfortable to raise, but a known effect worth naming.
Serious Side Effects to Watch For
These are separate from the list above. Each one has a specific action attached (National Library of Medicine / MedlinePlus, 2021-02-15).
Swelling of the face, throat, tongue, lips or eyes, hoarseness, or difficulty breathing or swallowing — if breathing is difficult or the swelling is coming on fast, call 911 or go to the nearest emergency room. Risk is higher in Black adults of African descent, women, older adults, people who smoke, and people taking aspirin or other NSAIDs (GoodRx Health, 2025-03-04).
Chest pain — call 911 or go to the emergency room.
Fainting — go to the emergency room; if you felt faint but did not pass out, call your doctor the same day.
Swelling of the hands, feet, ankles or lower legs — call your doctor the same day.
Fever, sore throat, chills or other signs of infection, or yellowing of the skin or eyes — call your doctor the same day.
If you become pregnant while taking lisinopril, call your doctor immediately; MedlinePlus states it should not be taken in pregnancy because it may harm the fetus.
Questions to Ask Your Doctor
"Which of my other medicines, including over-the-counter pain relievers, supplements and anything I take occasionally, could interact with lisinopril?"
"What blood pressure number are we aiming for, and how will we know this is working for me?"
"How often do you want my blood pressure and my blood tests checked, and who follows up on the results?"
"How long should I give this before we talk about whether it's doing its job?"
"What should I do if I miss a day, and what should I do if I notice I've taken it twice?"
"If I get the cough, what are my options, and how would we decide?"
"Is there anything about my kidneys, my age or my other conditions that changes how you'll watch this?"
Frequently asked questions
My blood pressure is normal now. Can I stop taking it?
No — not on your own. MedlinePlus is explicit that lisinopril controls the condition rather than permanently fixing it, that you should keep taking it even if you feel well, and that you should not stop without talking to your doctor (National Library of Medicine / MedlinePlus, 2021-02-15). A normal reading usually means the medication is doing what it was prescribed to do. Bring the question to your prescriber or pharmacist first.
How long until I know whether it's working?
The full effect may take up to four weeks (Wikipedia, citing AHFS Drug Information 2018). In the meantime, your blood pressure should be checked regularly to see how you are responding, and your doctor may order lab tests as well (National Library of Medicine / MedlinePlus, 2021-02-15). Keep those appointments even if you feel no different.
Will the dry cough go away?
People often report it starting within the first few weeks or months, though it can begin at any time, and it is often described as a tickling or scratching in the throat (GoodRx Health, 2025-03-04). Some people find it settles; others don't. Tell your prescriber if it is persistent or disruptive and ask what the options are — don't stop the medication on your own while you wait for that conversation.
Can I take ibuprofen or aspirin while I'm on lisinopril?
Ask your prescriber or pharmacist before adding either. GoodRx notes that people taking aspirin or other NSAIDs are among those more likely to develop swelling (angioedema) while on lisinopril (GoodRx Health, 2025-03-04). Also tell your doctor if you take valsartan and sacubitril (Entresto), or stopped it within the last 36 hours, or if you have diabetes and take aliskiren — these overlap with lisinopril on the same blood-pressure pathway and are generally not recommended together (National Library of Medicine / MedlinePlus, 2021-02-15).
Desmond writes about sleep, stress, and the slow erosion of both in modern life. He's most interested in the gap between what people know they should do and what actually gets them to do it.
