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How does lisinopril work?

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How it worksTime to workHow often?Side effectsOther medicationsSummary
Lisinopril is a common medication for treating hypertension. It works by helping to open up your veins and arteries, which allows your blood to flow more easily.
Medically reviewed by Ami Patel PharmD, BCPS
Written by Lily Frew
Updated on

If you have high blood pressure, there’s a good chance you take the medication lisinopril. This is a generic prescription medication that doctors have used for over 30 years to help lower blood pressure. You may know it under the brand names Zestril or Qbrelis.

Lisinopril is part of a family of blood pressure medications called angiotensin-converting enzyme (ACE) inhibitors. ACE inhibitors are the first medication doctors usually prescribe to manage high blood pressure due to the effectiveness found through research.

Like other ACE inhibitors, lisinopril works by helping your blood vessels relax, which in turn lowers your blood pressure.

How does lisinopril work?

An adult sitting in workout clothes on a yoga mat, wondering how lisinopril works.
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When the pressure in your blood vessels — which work like a hose for your blood to travel through — is very high, it can cause damage and tears over time. In arteries, those openings create pockets for low-density lipoprotein (LDL) cholesterol to collect.

These collections form plaques that make arteries thick and stiff. This puts you at risk for heart disease, heart attack, or stroke.

That’s why treating high blood pressure is so important. When your blood vessels are “elastic and open,” it makes your heart’s job easier.

In simple terms, lisinopril works by blocking an enzyme in the body that narrows blood vessels. This helps your blood vessels relax and open, lowering blood pressure and increasing blood and oxygen supply to the heart.

How long does lisinopril take to work?

On the drug label for Zestril, a branded form of lisinopril, you can see a drop in blood pressure within 24 hours at a dose of 5 milligrams (mg). However, the Food and Drug Administration (FDA) notes that the medication is more effective and works faster at higher doses of 10, 20, or 80 mg.

According to the National Institutes of Health (NIH), it takes between 6 and 8 hours for the concentration of lisinopril in your blood to reach its peak. This is when it is most effective, but it may start to get to work much quicker than this.

Regardless, long-term treatment is usually necessary for the following reasons:

How often do I have to take it?

Most people take lisinopril by mouth every day in either tablet or liquid form. The medication doesn’t cure high blood pressure but helps manage the condition. Lifestyle tweaks such as moving (even a little bit) every day and cutting back on alcohol if you drink can also help.

For lisinopril, consistency is key. It doesn’t matter when, but taking your medication at a regular time each day can help make sure your blood pressure remains steady throughout the day.

Doctors generally use lisinopril and other ACE inhibitors for the long-term management of hypertension, so you might take it for months or years at a time if it works for you with few side effects.

If it’s to treat a heart attack, you will likely take the medication for at least 6 weeks.

What are the most common side effects?

As with any medication, lisinopril can sometimes cause side effects. These include:

  • Dizziness: This can happen often, especially when getting up from sitting or lying down. To help avoid dizziness, stay hydrated unless your doctor has advised you to restrict fluids. Also, take your time when moving from different positions.
  • Low blood pressure: Sometimes, blood pressure medications can lower your blood pressure too much, leading to low blood pressure (hypotension). This is especially the case if you combine different hypertension medications, like adding a diuretic to lisinopril.
  • Dry cough: In some people, inhibiting ACE enzymes can trigger the cough reflex. This cough usually goes away quickly after you stop taking the drug.

Other side effects may include headaches, nausea, and extreme tiredness. You might also notice some more serious side effects, including:

Some doctors will slowly raise the dose of your medication to find the lowest effective dose for you while limiting side effects. If you do notice any, tell your doctor right away. They may be able to adjust your dose or prescribe another medication to ease the discomfort.

Other medications

While doctors may use lisinopril as a treatment on its own, it’s often combined with other drugs to help manage hypertension. For example, they often prescribe it alongside low doses of diuretics. Examples of these include:

If your doctor recognizes a need for you to take a diuretic, they may prescribe lisinopril with hydrochlorothiazide. This option comes in one pill under the brand name Zestoretic.

Other medications to help treat hypertension include:

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Lisinopril is a type of medication called an angiotensin-converting enzyme (ACE) inhibitor. It works by relaxing your blood vessels, allowing your blood to flow more easily and reducing how hard your heart needs to work.

It should get to work very quickly, and it’s used for the long-term management of hypertension. Doctors can also prescribe it as part of a treatment plan if you’re having a heart attack and be part of your recovery plan to help prevent another one.

Lisinopril may have some side effects, like dizziness and a dry cough. If these are difficult to manage, you can speak with a healthcare professional about finding an alternative.

Download the free Optum Perks Discount Card to save up to 80% on some prescription medications.

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