Naproxen Side Effects: What's Common, What's Serious, and What Women Report

Naproxen (brand names Aleve, Naprosyn) is a commonly used NSAID for pain and inflammation. Like other NSAIDs, it can cause side effects, most often involving the stomach and digestive system.

Common naproxen side effects include stomach upset, nausea, indigestion, heartburn, dizziness, and headache. These effects are usually mild, but naproxen can also cause more serious problems, including gastrointestinal bleeding, kidney injury, cardiovascular events, and severe allergic reactions. The risk generally increases with higher doses, longer treatment, and certain health conditions or medication combinations.

Women may have additional questions about naproxen, particularly its effects on menstrual symptoms, fertility, pregnancy, and breastfeeding. Some of these concerns are well established, while others depend on the dose, duration of treatment, and individual circumstances.

Here's what to know about common naproxen side effects, serious warning signs, and the situations in which women should talk with a clinician before taking it.

TL;DR: Key Takeaways

• The most common naproxen side effects involve the digestive system, including stomach upset, nausea, indigestion, and heartburn.
• Serious risks include gastrointestinal bleeding, kidney problems, cardiovascular events, and severe allergic reactions.
• The risk of serious side effects increases with higher doses, longer use, older age, and certain medical conditions or medication combinations.
• Naproxen can help relieve menstrual cramps, but NSAIDs may also temporarily affect ovulation in some women.
• If you're trying to conceive, discuss regular naproxen use with a clinician because NSAIDs may be associated with a reversible delay in ovulation.
• FDA recommends avoiding NSAIDs, including naproxen, at 20 weeks of pregnancy or later unless specifically advised by a healthcare professional.
• Adults 65 and older have a higher risk of gastrointestinal and kidney complications from NSAIDs.
• Seek urgent medical attention for signs of internal bleeding, chest pain, stroke symptoms, or a severe allergic reaction.

Experiencing naproxen side effects and want a clinician to review your situation? Book a $39 online urgent care visit with August AI. A US-licensed clinician can review your symptoms and recommend next steps when clinically appropriate. The visit does not guarantee a prescription, and medication costs are separate. For severe symptoms, pregnancy concerns, or symptoms that need an in-person evaluation, primary care or urgent care may be more appropriate.

Common naproxen side effects: what most people experience

Most naproxen side effects are relatively mild. Because naproxen reduces prostaglandins, substances that help protect the stomach lining as well as contribute to pain and inflammation, digestive symptoms are among the side effects people may notice.

GI effects

Common digestive side effects include:

• Stomach upset or discomfort
• Nausea
• Indigestion
• Heartburn
• Constipation
• Diarrhea
• Loss of appetite

Taking naproxen with food can help reduce stomach upset, although it does not eliminate the risk of ulcers or gastrointestinal bleeding.

Central nervous system effects

Some people may experience:

• Headache
• Dizziness
• Drowsiness
• Fatigue

These effects can be more noticeable when you first start taking the medication.

Other possible effects

Other reported effects can include:

• Ringing in the ears, or tinnitus
• Mild swelling or fluid retention
• Skin reactions or increased sensitivity to sunlight

Not everyone experiences these effects, and having a side effect does not necessarily mean you need to stop the medication. Persistent or troublesome symptoms are worth discussing with a clinician.

For a fuller look at how naproxen works and how long effects last, see our guide on how long does naproxen take to kick in? A timeline from first pill to full relief.

Serious side effects: what to watch for

Serious naproxen side effects are less common, but they can be dangerous when they occur. Some require immediate medical attention.

GI bleeding and ulcers

NSAIDs can cause stomach or intestinal ulcers and bleeding. Warning signs include:

• Black or tarry stools
• Vomiting blood or material that looks like coffee grounds
• Severe or persistent abdominal pain
• Unexplained weakness, dizziness, or other signs of significant blood loss

The risk is higher in older adults, people with a history of ulcers or gastrointestinal bleeding, people taking blood thinners or corticosteroids, and people using higher doses or taking NSAIDs for longer periods.

Kidney problems

Naproxen can reduce blood flow to the kidneys and may cause kidney injury, particularly in people who already have kidney disease or who are dehydrated.

Possible warning signs include:

• Noticeably decreased urine output
• New or worsening swelling
• Unusual weakness
• Shortness of breath

Risk can also increase with certain medication combinations, including some blood-pressure medicines and diuretics.

Cardiovascular events

NSAIDs, including naproxen, can increase the risk of heart attack and stroke. The risk can be higher with higher doses and longer treatment, particularly in people who already have cardiovascular disease or other risk factors.

Seek urgent medical attention for chest pain, sudden shortness of breath, sudden weakness, facial drooping, difficulty speaking, or other possible signs of a heart attack or stroke.

Severe allergic reactions

A serious allergic reaction can cause hives, facial or throat swelling, wheezing, or difficulty breathing. These symptoms require emergency medical attention.

Liver problems

Liver injury is uncommon but possible. Contact a clinician if you develop yellowing of the skin or eyes, dark urine, unusual fatigue, or persistent upper abdominal pain.

Hearing effects

Tinnitus has been reported with naproxen. Persistent ringing in the ears or changes in hearing should be discussed with a clinician, particularly if symptoms develop after starting or increasing the medication.

For a comparison of naproxen dosing and when higher doses require more caution, see our guide on is naproxen 500 mg a strong painkiller? How it compares to 250 mg, Aleve, and ibuprofen.

Naproxen side effects specific to women

Naproxen can be particularly relevant for women because it is commonly used for menstrual cramps, while pregnancy and fertility introduce additional considerations.

Menstrual effects

Naproxen is commonly used to reduce menstrual pain because prostaglandins contribute to uterine contractions and menstrual cramping.

Rather than causing increased menstrual bleeding in most users, NSAIDs can actually reduce menstrual blood loss for some women with heavy periods. However, an unexpected change in bleeding pattern should not automatically be attributed to naproxen.

If your period becomes unusually heavy, prolonged, irregular, or otherwise different from your normal pattern, talk with a clinician. There may be another explanation that needs evaluation.

Fertility considerations

NSAIDs can interfere with prostaglandins involved in ovulation. Some NSAID labeling advises women who are trying to become pregnant that these medicines may be associated with a reversible delay in ovulation.

This does not mean that occasional naproxen use causes infertility. However, if you're having difficulty conceiving or using naproxen regularly while trying to become pregnant, discuss your medication use with a clinician.

Pregnancy

Pregnancy is one of the most important situations in which naproxen use needs medical guidance.

FDA recommends avoiding NSAIDs, including naproxen, at 20 weeks of pregnancy or later unless a healthcare professional specifically advises their use. NSAID use from around 20 weeks onward can cause fetal kidney problems and low amniotic fluid. At around 30 weeks and later, there is an additional risk of premature closure of the fetal ductus arteriosus.

If an NSAID is considered necessary between about 20 and 30 weeks, FDA recommends the lowest effective dose for the shortest duration. If treatment continues beyond 48 hours, clinicians may consider monitoring amniotic fluid.

If you are pregnant, might be pregnant, or are planning pregnancy, talk with your clinician before taking naproxen.

Breastfeeding

Small amounts of naproxen can pass into breast milk. Short-term use may sometimes be considered when clinically appropriate, but the decision depends on the mother's need for treatment and the baby's circumstances.

If you need naproxen repeatedly or for an extended period while breastfeeding, discuss the medication with your clinician. The FDA labeling recommends weighing the benefits of breastfeeding and the mother's clinical need against potential effects on the infant.

Hormonal considerations

There is not a well-established interaction between naproxen and hormonal birth control that makes routine contraceptive use unsafe.

However, if you take prescription hormones, fertility medications, or other medicines regularly, tell your clinician or pharmacist about all of them before starting long-term or high-dose naproxen.

Naproxen side effects in older adults

Adults 65 and older can be more vulnerable to NSAID complications, particularly gastrointestinal bleeding and kidney problems.

This is partly because kidney function can decline with age, and older adults are also more likely to take several medications that can interact with NSAIDs.

If you or a family member over 65 needs regular naproxen for ongoing pain, it is worth reviewing the dose, duration, other medications, and possible alternatives with a clinician.

How to reduce naproxen side effects

You cannot eliminate the risks of naproxen, but several practical steps can reduce unnecessary exposure.

For stomach protection

• Use the lowest effective dose for the shortest appropriate duration.
• Take naproxen with food if it causes stomach upset.
• Avoid combining naproxen with other NSAIDs unless specifically instructed.
• Limit alcohol, particularly if you use naproxen regularly.
• Ask a clinician whether additional stomach protection is appropriate if you have a high risk of GI complications.

For kidney protection

• Stay adequately hydrated, particularly during illness or periods when you may lose fluids.
• Tell your clinician if you have kidney disease.
• Review your other medications before using naproxen regularly.

For overall safety

• Follow the prescribed or package directions.
• Do not increase the dose because the medication does not seem to be working quickly enough.
• Tell your clinician about new or persistent side effects.
• If you need naproxen regularly for chronic pain, discuss whether another treatment strategy may be more appropriate.

When to contact a clinician

Call 911 or your local emergency line, seek emergency care now if you have:

• Black or tarry stools
• Vomiting blood or coffee-ground-like material
• Severe or sudden abdominal pain
• Chest pain or sudden shortness of breath
• Sudden weakness, facial drooping, or speech changes
• Severe facial, tongue, or throat swelling
• Difficulty breathing
• A severe allergic reaction
• Severe symptoms suggesting significant blood loss, such as extreme weakness, fainting, or rapid heartbeat

Contact a clinician soon if you:

• Have persistent stomach pain, indigestion, or other GI symptoms
• Notice unusual bruising or bleeding
• Develop new or worsening swelling
• Notice a significant change in urine output
• Develop persistent dizziness, fatigue, or ringing in the ears
• Need to use naproxen regularly for an extended period
• Notice an unexpected change in menstrual bleeding
• Are having difficulty conceiving while using NSAIDs regularly

Talk to a clinician before starting naproxen if you:

• Have a history of ulcers or GI bleeding
• Have kidney or liver disease
• Have heart failure, cardiovascular disease, or high blood pressure
• Take blood thinners
• Take aspirin, corticosteroids, or other medications that can increase bleeding or kidney risks
• Are pregnant or planning pregnancy
• Are over 65
• Have a bleeding disorder
• Take several prescription or over-the-counter medications

Conclusion

Most naproxen side effects are mild, particularly with appropriate short-term use. Stomach upset, nausea, indigestion, and dizziness are among the effects people may notice.

Serious complications such as gastrointestinal bleeding, kidney problems, cardiovascular events, and severe allergic reactions are less common but can be dangerous. The risk increases with higher doses, longer use, older age, and certain health conditions or medication combinations.

For women, naproxen has some additional considerations. It can be useful for menstrual cramps, but regular NSAID use may temporarily affect ovulation in some women. Pregnancy also changes the risk profile: FDA recommends avoiding NSAIDs at 20 weeks of pregnancy or later unless a clinician specifically advises their use.

For chronic pain that requires regular treatment, discuss the dose, duration, and alternatives with your clinician. For occasional OTC naproxen such as Aleve, follow the package directions and avoid using more than recommended.