Naproxen sodium is a nonsteroidal anti-inflammatory drug (NSAID) used to relieve pain, reduce inflammation, and lower fever. It’s available over the counter under the brand name Aleve and in stronger prescription forms like Naprosyn and Anaprox. Its versatility makes it one of the most widely used pain relievers, treating everything from headaches and menstrual cramps to chronic arthritis and acute gout attacks.
How Naproxen Sodium Works
When your body is injured or inflamed, it releases a fatty acid called arachidonic acid from cell membranes. Enzymes then convert that acid into prostaglandins and thromboxanes, chemical messengers that trigger pain, swelling, and fever. Naproxen blocks the two forms of those enzymes (called COX-1 and COX-2), reducing the production of these inflammatory signals at their source. This is the same basic mechanism shared by ibuprofen and aspirin, though naproxen lasts considerably longer in the body, which means fewer doses throughout the day.
Over-the-Counter Uses
Most people encounter naproxen sodium as an OTC pill for everyday pain. At nonprescription strength, it’s used to relieve mild to moderate pain from headaches, muscle aches, backaches, toothaches, menstrual cramps, and the common cold. It also reduces fever. A single OTC dose typically provides relief for 8 to 12 hours, which is longer than ibuprofen or acetaminophen and makes it a practical choice when you don’t want to re-dose frequently during the day or overnight.
Prescription Uses
At higher doses, naproxen is prescribed for a broader range of inflammatory conditions. The FDA has cleared prescription naproxen for the following:
- Rheumatoid arthritis: chronic joint inflammation caused by the immune system attacking joint linings
- Osteoarthritis: joint pain from the gradual breakdown of cartilage
- Ankylosing spondylitis: a form of arthritis primarily affecting the spine
- Juvenile arthritis: joint disease in children
- Tendonitis and bursitis: inflammation of tendons or the fluid-filled sacs that cushion joints, particularly in the shoulder
- Acute gout: sudden, intense joint pain caused by a buildup of uric acid crystals
- Primary dysmenorrhea: painful menstrual cramps
- General pain management
Naproxen is also sometimes used off-label for Paget’s disease of bone, a condition where bones become abnormally thick and fragile.
Naproxen for Menstrual Cramps
Menstrual pain is one of the most common reasons people reach for naproxen sodium. Cramps happen because the uterus produces high levels of prostaglandins during a period, and since naproxen directly blocks prostaglandin production, it targets the root cause rather than just masking the sensation. Clinical trials comparing naproxen sodium to placebo for menstrual pain have shown it to be significantly more effective at reducing both pain intensity and associated symptoms. For the best results, taking it at the first sign of cramps (or even just before your period typically starts) gives it time to lower prostaglandin levels before they peak.
Naproxen for Gout Attacks
Acute gout flares cause rapid, severe joint pain, often in the big toe, and naproxen is a first-line treatment. Prescription dosing for gout starts higher than the usual arthritis dose: 750 mg as an initial loading dose, followed by 250 mg every eight hours until the flare subsides. This aggressive front-loading helps bring the intense inflammation under control quickly. Gout flares can last days to weeks without treatment, so starting naproxen early in an attack shortens the episode considerably.
OTC vs. Prescription Strength
Over-the-counter naproxen sodium (Aleve) comes in 220 mg tablets, with a typical adult dose of one tablet every 8 to 12 hours and a daily maximum of two to three tablets. Prescription naproxen comes in higher strengths, typically 250 mg, 375 mg, or 500 mg tablets taken twice daily. The maximum prescription dose is generally 1,500 mg per day, though the exact amount depends on the condition being treated. There’s also a delayed-release prescription form designed to dissolve in the intestine rather than the stomach, which may reduce some digestive irritation.
The active ingredient is the same across all forms. The difference is simply how much you’re taking per dose and whether a healthcare provider is guiding the dosing for a specific condition.
Side Effects and Risks
The most common side effects of naproxen are digestive: stomach pain, heartburn, nausea, and indigestion. These tend to be more frequent with higher doses and longer use. Taking naproxen with food or a full glass of water can help reduce stomach irritation.
More serious risks involve the gastrointestinal tract and the cardiovascular system. Naproxen can cause stomach ulcers, bleeding, or tears in the stomach or intestinal lining. These problems can develop at any time during use, sometimes without warning symptoms, and become more likely the longer you take the drug. People over 65, those with a history of stomach ulcers, and anyone taking blood thinners face a higher risk.
Like all NSAIDs, naproxen also carries a risk of blood clots, heart attack, and stroke. These cardiovascular risks increase with long-term use and in people who already have heart disease. That said, some research suggests naproxen may carry a somewhat lower cardiovascular risk compared to certain other NSAIDs, which is one reason it remains a common choice for people who need regular anti-inflammatory treatment.
Who Should Be Cautious
Naproxen is not a good fit for everyone. People taking blood-thinning medications need to be especially careful, because naproxen interferes with platelet function and increases bleeding risk. It can also raise blood pressure and reduce the effectiveness of some blood pressure medications. If you take lithium for a mood disorder, naproxen can increase lithium levels in your blood to a potentially dangerous degree.
People with kidney disease, liver disease, or a history of stomach bleeding should generally avoid naproxen or use it only under close supervision. The drug is also not recommended during the last trimester of pregnancy, as it can affect fetal heart development and delay labor. For older adults, the combination of cardiovascular, gastrointestinal, and kidney risks means that the lowest effective dose for the shortest possible time is the standard approach.