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Boxed Warning

A boxed warning is the highest safety warning issued by the US Food and Drug Administration (FDA) and should be discussed with a doctor before beginning a medication. The FDA has issued a boxed warning for non-steroidal anti-inflammatory drugs (NSAIDs), including naproxen, due to their associated cardiovascular and GI risks.

NSAIDs have been shown to increase the risk of stroke, heart attack, and other cardiovascular events that may be fatal. These adverse effects can happen at any time during treatment, and their risk may increase the longer the drug is taken.¹

Naproxen should not be taken in association with coronary artery bypass graft surgery.

NSAIDs also cause an increased risk of serious gastrointestinal (GI) complications like bleeding, ulcers, and perforation of the stomach or intestine, which can also be life-threatening. Older adults with a previous ulcer or GI bleeding are more likely to develop these adverse gastrointestinal complications.

Naproxen is in the class of non-steroidal anti-inflammatory drugs (NSAIDs), which are commonly taken to relieve pain, reduce inflammation, or bring down a fever. Some of the available strengths can be bought over the counter, while others require a prescription.

Although widely used, NSAIDs aren't suitable for everyone and can sometimes cause adverse effects.

If you are taking over-the-counter naproxen, read the boxed warning first and follow the instructions carefully. Or, if you are taking prescription naproxen, follow your doctor’s instructions regarding how and when to take it.

What is naproxen?

Naproxen is a non-steroidal anti-inflammatory drug (NSAID) used to help reduce swelling and pain caused by various health conditions. It works by indirectly inhibiting the action of the cyclooxygenase enzymes, COX-1 and COX-2, which normally cause a series of chemical reactions in the body leading to pain and inflammation. When these COX enzymes are blocked, some of the body's inflammatory mediators, prostaglandins and thromboxanes, are not produced, resulting in reduced inflammation and pain. For this reason, naproxen is classified as an analgesic (pain-relief drug).²

What is naproxen used to treat?

Prescription-strength naproxen is used for treating various conditions associated with pain, inflammation, and swelling. These are the FDA-approved indications:³

  • Osteoarthritis—an inflammatory degenerative joint disease that causes the tissue lining the joints to break down

  • Polyarticular juvenile idiopathic arthritis (JIA)—a form of inflammatory joint disease in children

  • Rheumatoid arthritis—an autoimmune condition that causes inflammation in the lining of the joints

  • Ankylosing spondylitis—another form of inflammatory arthritis (and also an autoimmune disease) that typically affects the mobility of bones in the spine (vertebrae), and may involve other areas of the body, such as the feet and hips

  • Tendonitis—inflammation of the tissue connecting muscles to bones

  • Bursitis—inflammation of fluid-filled sacs (bursa) that cushion various joints in the body, including shoulders, hips, knees, elbows, and ankles

  • Acute gouty arthritis—episodes of inflammation and pain caused by crystals that form in the joints due to excessive amounts of uric acid (a waste product) in the bloodstream

Naproxen is sometimes prescribed off-label to prevent and treat migraine headaches, but it is not FDA-approved for this use.⁴

Over-the-counter (OTC) naproxen is commonly used to reduce a fever or relieve pain from:

  • Muscle aches

  • Minor injuries

  • Headaches

  • Viral infections

  • Backaches

  • Toothaches

  • Menstrual cramping

  • Post-operative pain

Dosage forms and strengths

Naproxen is available in both OTC and prescription forms. 

There are two formulations of prescription naproxen: naproxen sodium and naproxen. Naproxen sodium is available as an oral extended-release or immediate-release tablet. Naproxen comes as an oral suspension (liquid), an immediate-release tablet, and a delayed-release tablet.

Here are the available naproxen/naproxen sodium strengths listed by formulation:

Immediate release tablet (generic)⁵ ⁶

  • 220mg (OTC: Aleve)

  • 250mg

  • 275mg

  • 375mg

  • 500mg (Naprosyn, Anaprox DS)

  • 550mg

Delayed release tablet (generic, EC-Naprosyn)⁷

  • 375mg

  • 500mg

Extended-release tablet (generic, Naprelan)⁸

  • 375mg

  • 500mg

  • 750mg

Capsule/liquid gel

  • 220mg (generic, OTC: Aleve)

Oral suspension

  • 125mg/mL (generic, Naprosyn)⁹

Naproxen and naproxen sodium are sold under a variety of brand names, including:

  • Aleve

  • Naprosyn

  • Aflaxen

  • Anaprox DS

  • Naprosyn

  • EC Naprosyn

  • Flanax

  • Naprelan

Naproxen and naproxen sodium are also found in combination formulations for the treatment of migraines, allergies, and cold symptoms.

How do you take naproxen?

Naproxen is usually taken every 12 hours for pain relief or every 8 hours to treat acute gouty arthritis.

How you take it will depend on the formulation, dosage strength, age, the condition being treated, other medicines you take, and any other medical conditions you may have.

Taking naproxen with a meal may help prevent stomach upset. Follow any instructions or recommendations from your doctor or pharmacist, whether you are taking prescription-strength or OTC naproxen.

To manage the risk of side effects, it is recommended to take the lowest dose of naproxen needed to treat your symptoms effectively and for the shortest amount of time possible.

Tablets and capsules

Naproxen, whether OTC or by prescription, is taken by mouth in the form of capsules or tablets. Follow the dosing instructions contained in the package or on your prescription, and take them with a glass of water as indicated.

If you're taking this NSAID daily for chronic pain management, try to take it around the same time of day. Swallow the tablets whole—do not crush, chew, or split them.


If you're taking the liquid suspension form of naproxen, shake it well to mix the medicine before use. Then use an oral syringe or a measuring cup provided by your pharmacist to measure the correct amount of liquid. Do not use a utensil from home because it will not measure your dose accurately.

Seeing results

Our bodies respond differently to medications. Therefore, the time it takes to see results after taking naproxen varies from one person to another. Results will also depend on the form and strength of naproxen taken and the condition being treated.

If you're taking naproxen to relieve pain, you should notice improvements within an hour or so, but for some chronic conditions, it may take one to two weeks of regular use to experience the full benefits.¹⁰

If the symptoms you are treating worsen or do not improve, or you develop any new or unexpected symptoms while taking naproxen, contact your doctor.

Who should not take naproxen?

Naproxen is not suitable for everyone. Individuals with certain health conditions should avoid or take it with caution.¹¹

Some reasons you may not be able to take naproxen include the following: 

  • History of an allergic reaction (hives, rash, swelling, anaphylaxis) to naproxen (or its components), aspirin, or any other NSAIDs

  • Having asthma triggered by aspirin or NSAIDs

  • Having had or planning coronary artery bypass surgery

  • Being in the second and third trimesters of a pregnancy

  • Having reduced kidney function or kidney disease

  • Taking anticoagulant (blood thinner) medications

In addition, naproxen must be taken with caution, and its use monitored closely if you have any of the following:

  • Recent heart attack, congestive heart failure, or heart disease or risk

  • High blood pressure

  • Asthma

  • Swelling or fluid retention

  • Peptic ulcer, gastritis, gastrointestinal reflux, or a history of ulcers or gastrointestinal bleeding

  • Blood clotting disorder, or history of a stroke

  • Severe kidney or liver disease

  • Chronic alcohol use or alcohol use disorder

  • Tobacco use

  • Dehydration

  • Sodium-restricted diet

  • Pregnant, breastfeeding, or trying to get pregnant

  • Older adult

Always talk to your doctor before taking naproxen to prevent possible adverse effects.

Potential side effects of naproxen

Naproxen can cause side effects ranging from mild to severe. However, particularly when taken as directed, not everyone who uses naproxen will experience side effects.¹²

Common side effects

  • Headache

  • Confusion

  • Dizziness

  • Constipation or diarrhea

  • Abdominal pain 

  • Heartburn

  • Nausea

  • Ringing in the ears

  • Lightheadedness

  • Drowsiness

  • Burning or tingling in the arms or legs

  • Difficulty falling asleep or staying asleep

  • Fluid retention, swelling

  • High blood pressure

  • GI ulcers 

  • Skin rash, itching, hives

Severe adverse effects

  • Shortness of breath, wheezing, or difficulty breathing or swallowing (allergic reaction)

  • Chest pain (heart attack, heart failure)

  • Stroke

  • Bloody vomit or stools (gastrointestinal bleeding)

  • Severe abdominal pain (gastritis)

  • Swelling of the face, eyes, lips, arms, throat, or hands (angioedema)

  • Excessive tiredness

  • Fluid retention (kidney dysfunction)

  • Yellowing of the eyes or skin (liver dysfunction)

  • Purple spots under the skin or bruising (low platelets)

  • Decreased urination (kidney injury or failure)

  • Flu-like symptoms (agranulocytosis)

  • Severe, peeling skin rash (Stevens-Johnson syndrome, toxic epidermal necrolysis)

Note that this is not a complete list of potential naproxen side effects.

You should always follow your doctor's recommendation or the instructions on the product label when taking naproxen to reduce risks and prevent adverse effects.

While you can find ways to cope with mild side effects, you should stop taking naproxen and contact your doctor if they do not improve or worsen.

If you have any signs of a severe reaction to the drug, seek medical attention immediately.


Symptoms of naproxen overdose include:¹³

  • Drowsiness

  • Vomiting

  • Slow or difficulty breathing

  • Stomach pain

  • Extreme tiredness

  • Heartburn

  • Gastrointestinal bleeding

  • Seizure

  • Coma

If you suspect that you or someone you know has taken too much naproxen, you can call the National Poison Control helpline at 1-800-222-1222. If you believe someone has overdosed and experiences symptoms like trouble breathing, nausea, or signs of gastrointestinal bleeding, call 911.

Missed doses

If you're taking naproxen on a regular schedule and you miss a dose, take the missed dose as soon as you remember. But if it's almost time for the next dose, skip the missed one and start back on your regular dosing schedule. Don't take a double dose to make up for the missed dose.

Drug interactions

Some drugs can alter the way naproxen works and reduce or change its effectiveness. Similarly, combining naproxen with other substances can cause unexpected reactions and harmful side effects. Be sure to tell your doctor about all medications, herbs, supplements, and substances you take before using naproxen.

Drugs and substances that are known to interact with naproxen include, but are not necessarily limited to:¹⁴

  • Alcohol

  • Antibiotics like gentamicin, streptomycin, and tobramycin

  • Antidepressants, such as paroxetine (Paxil), citalopram (Celexa), fluvoxamine (Luvox), and fluoxetine (Prozac)

  • Anticoagulants such as warfarin (Coumadin), apixaban (Eliquis), and enoxaparin (Lovenox)

  • Blood pressure medicines, such as:

    • Beta-blockers like propranolol (Inderal), labetalol (Trandate), and metoprolol (Lopressor)

    • Angiotensin-converting enzyme (ACE) inhibitors like captopril (Capoten), enalapril (Vasotec), and lisinopril (Zestril)

    • Angiotensin receptor blockers (ARBs) like losartan (Cozaar), candesartan (Atacand), and others

  • Diuretics, such as furosemide (Lasix) and hydrochlorothiazide (Aquazide H, Hydrocot)

  • Digoxin (Lanoxin)

  • Immunosuppressants like methotrexate (Trexall), tacrolimus (Prograf), and cyclosporine (Neoral)

  • Lithium (Lithobid)

  • Other NSAIDs, such as aspirin, meloxicam (Mobic), celecoxib (Celebrex), ibuprofen (Motrin, Advil), and others

  • Steroids like methylprednisolone (Medrol), prednisone, and others 

  • Garlic, gingko, licorice, fenugreek, and willowbark

This is not a complete list of drug interactions, so make sure to review your medication list with your doctor before taking naproxen.

Can I drink alcohol while taking naproxen?

Drinking alcohol while taking naproxen can increase your risk of gastrointestinal bleeding and other side effects. Therefore, it is generally not recommended to drink alcohol while taking naproxen or any other NSAIDs.

What to discuss with your doctor before starting naproxen

Review any concerns and risk factors with your doctor, such as:

  • Any history of an allergic reaction to naproxen or other NSAIDs like aspirin and ibuprofen, pain or fever relief medications, or any of the ingredients in the naproxen products

  • Any medical conditions you have, particularly heart, liver, or kidney disease, high blood pressure, diabetes, high cholesterol, history of a heart attack, stroke, blood clot, peptic ulcer, or gastrointestinal bleeding

  • All prescription and non-prescription drugs, nutritional supplements, vitamins, and herbal products you're currently using, take occasionally, or plan to use

  • If you are on a low sodium diet

  • If you are pregnant, planning a pregnancy, or breastfeeding

  • If you're having surgery or any medical or dental procedures

Pregnancy category

During the first trimester, naproxen is classified by the FDA as a pregnancy category B drug. This means reproductive studies in animals did not demonstrate a risk to the fetus, and there are no adequate, well-controlled human studies from which a risk can be determined.

In the second and third trimesters, naproxen is designated a pregnancy category D drug, indicating evidence of human fetal risk. NSAIDs, including naproxen, are associated with a rare but serious risk of injury to the fetal kidneys, which can lead to lower amniotic fluid levels. Sufficient amniotic fluid is essential for fetal organ system development.¹⁵

It is also established that the use of NSAIDs during the second half of pregnancy poses a serious risk of premature closure of the fetal ductus arteriosus and persistent pulmonary hypertension that can lead to serious heart problems in the newborn.¹⁶

In 2020, the FDA officially updated its safety warning to recommend against the use of NSAIDs from the 20th week of pregnancy onward. Previous guidance had cautioned against NSAID use after the 30 week mark.

Naproxen and pregnancy

Naproxen (and all other NSAIDs) should not be used from 20 weeks of pregnancy and beyond unless your doctor determines that the drug’s expected benefits outweigh the risks to the fetus. In these rare cases, it will be prescribed for the shortest time possible with close monitoring by ultrasound.¹⁷ 

Many OTC pain relief products (including, but not limited to, naproxen, ibuprofen, and aspirin) contain NSAIDs, as do certain combination products (such as cold and sinus formulas). Always check the ingredients and box warning on OTC products before using them. 

You may wish to ask your doctor which mild-to-moderate pain relief options are generally safe and appropriate for use as needed while pregnant or breastfeeding.

Using naproxen while breastfeeding

Relatively small amounts of naproxen enter breast milk, and adverse effects are uncommon. 

There are reports of infant health issues in relation to breastfeeding during use of naproxen, but it remains unclear whether the symptoms were caused by naproxen, another medication taken at the same time, or other factors.¹⁸

If you are considering taking naproxen while breastfeeding, review the indications with your doctor and discuss the risks and benefits.

Stopping naproxen

Stopping self-prescribed, over-the-counter naproxen taken short-term for acute painful conditions, such as injury or back pain, doesn’t usually require any special measures other than discontinuing use once the condition has improved.

However, if the drug has been prescribed long-term to treat a chronic inflammatory condition, such as arthritis, consult your doctor for guidance before discontinuing the medication.

Long-term effects

Speak to your doctor before using naproxen (or any other NSAID) for more than 10 days.¹⁹

Both short-term and long-term effects of this medication include an elevated risk of GI side effects, such as ulcers and bleeding, as well as increased cardiovascular risks.

Taking the lowest effective dose of this medication for the shortest period of time is an appropriate way to manage the potential risks associated with naproxen, especially for older adults.²⁰ ²¹

Drug approval history

Naproxen was patented in 1967 and first approved for medical use nine years later in 1976. In 1994, it was approved by the FDA for over-the-counter use.²² ²³

Tips for taking naproxen

  • Be sure to take naproxen as directed by your doctor or according to the product instructions.

  • It is helpful to take naproxen with food or a full glass of water to reduce stomach upset.

  • If you are taking an OTC form of naproxen, it is important to follow all dosing instructions on the package and not to take more than the recommended dose.

  • Don’t take naproxen if you are dehydrated. Make sure to let your doctor know, so that you can receive treatment if needed and find out when to start back on your regular dose.

  • Check with your doctor or pharmacist if you are planning to take any medications for pain, fever, or cold and flu symptoms because some of them contain NSAIDs. Also, any time a doctor starts you on a new medication, tell them you are taking an NSAID.

  • Naproxen can affect the results of certain blood tests, so let your doctor know that you are taking it whenever you are going to have blood drawn.

  • Watch closely for any signs of gastrointestinal bleeding, such as blood in your stools or vomit, and stop the medication and seek immediate medical attention if these symptoms occur.

Frequently asked questions

Is naproxen hard on the liver?

In rare cases, naproxen has been associated with severe liver inflammation, including acute hepatitis and acute liver injury. Speak with your doctor before taking naproxen if you have a history of liver disease.²⁴

Is naproxen 500mg a strong painkiller?

NSAIDs like naproxen primarily treat inflammation, which is the source of many types of pain. Although not the strongest possible painkiller, it is typically powerful enough to manage mild to moderate inflammation-related pain without the side effects of narcotics like opioids.

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Here at HealthMatch, we’ve done our best to ensure that the information provided in this article is helpful, up to date, and, most importantly, accurate.

However, we can’t replace the one-to-one advice of a qualified medical practitioner or outline all of the possible risks associated with this particular drug and your circumstances.

It is therefore important for you to note that the information contained in this article does not constitute professional medical or healthcare advice, diagnosis or recommendation of treatment and is not intended to, nor should be used to, replace professional medical advice. This article may not always be up to date and is not exhaustive of all of the risks and considerations relevant to this particular drug. In no circumstances should this article be relied upon without independent consideration and confirmation by a qualified medical practitioner.

Your doctor will be able to explain all possible uses, dosages, precautions, interactions with other drugs, and other potential adverse effects, and you should always talk to them about any kind of medication you are taking, thinking about taking or wanting to stop taking.

Curious about clinical trials?

Access the latest treatments and medications. unavailable elsewhere - entirely free of charge. We make it easy to take part.