NSAIDs, or nonsteroidal anti-inflammatory drugs, are a class of medications that reduce pain, inflammation, and fever. They’re among the most widely used drugs in the world, and you’ve almost certainly taken one. The most common examples include ibuprofen (Advil, Motrin), naproxen (Aleve), and aspirin. But the category extends well beyond those familiar names to include several prescription-strength options used for arthritis, post-surgical pain, and other inflammatory conditions.
How NSAIDs Work
Your body produces chemicals called prostaglandins at sites of injury or illness. Prostaglandins trigger inflammation, swelling, and pain, and they also raise your body temperature during a fever. NSAIDs work by blocking the enzymes (called COX-1 and COX-2) that your body needs to produce those prostaglandins. By cutting off prostaglandin production at the source, NSAIDs reduce all three symptoms at once: pain, swelling, and fever.
The catch is that COX-1 also helps maintain the protective lining of your stomach and supports normal kidney function. This is why NSAIDs can cause stomach problems. Some newer NSAIDs were designed to block mainly COX-2, the enzyme more directly tied to inflammation, while leaving COX-1 alone. Celecoxib (Celebrex) is the most widely used of these selective COX-2 inhibitors.
Over-the-Counter NSAIDs
Three NSAIDs are available without a prescription in the United States:
- Ibuprofen (sold as Advil and Motrin). The standard adult dose for mild to moderate pain is 400 mg every four to six hours as needed. For chronic conditions like arthritis, doses can go up to 3,200 mg per day under medical supervision.
- Naproxen (sold as Aleve and Naprosyn). Naproxen lasts longer than ibuprofen, so it’s typically taken every 8 to 12 hours instead of every 4 to 6. This makes it a practical choice when you want fewer doses throughout the day.
- Aspirin. The original NSAID. At standard doses (325 to 650 mg), aspirin works as a pain reliever and anti-inflammatory. At a much lower dose (81 mg per day), it acts primarily as a blood thinner to help prevent heart attacks and strokes. This dual identity makes aspirin unique among NSAIDs.
Prescription NSAIDs
When over-the-counter options aren’t strong enough, or when a condition requires a specific type of anti-inflammatory action, doctors can prescribe stronger NSAIDs. Common prescription examples include:
- Diclofenac. Available as oral tablets, topical gels, and patches. The topical form is popular for localized joint pain because it delivers the drug directly to the site without as much systemic exposure.
- Celecoxib (Celebrex). The main COX-2 selective NSAID still on the market. Because it largely spares COX-1, it’s generally easier on the stomach than traditional NSAIDs, which makes it a common choice for people who need long-term anti-inflammatory treatment.
- Meloxicam. Frequently prescribed for osteoarthritis and rheumatoid arthritis. Like naproxen, it has a long duration of action and is typically taken once daily.
- Indomethacin. One of the stronger NSAIDs, often used for gout flares and certain types of inflammatory joint disease.
Higher-dose versions of ibuprofen and naproxen are also available by prescription, offering the same active ingredient you’d buy off the shelf but in stronger formulations.
What NSAIDs Are Used For
The most common uses are headaches, muscle aches, menstrual cramps, toothaches, arthritis, and reducing fever from colds or the flu. The American Dental Association’s 2024 clinical guideline specifically recommends NSAIDs, either alone or combined with acetaminophen, as the first-line treatment for dental pain in adults and adolescents, favoring them over opioids for managing pain after extractions or during toothaches.
For chronic conditions like osteoarthritis and rheumatoid arthritis, NSAIDs are a mainstay of symptom management. They don’t slow the underlying disease, but they can significantly reduce the daily stiffness, swelling, and pain that limit mobility.
Stomach and Digestive Risks
The most well-known risk of NSAIDs is gastrointestinal damage. Because these drugs suppress COX-1, which helps protect your stomach lining, regular use can lead to irritation, ulcers, and bleeding. Even low doses of NSAIDs can roughly triple the risk of developing a peptic ulcer. In older adults, the prevalence of GI bleeding associated with NSAID use ranges from about 2.5% to 4.5%. For aspirin specifically, about 1 in 100 patients who take it for around two years will experience GI bleeding.
You can lower this risk by taking NSAIDs with food, using the lowest effective dose, and avoiding long stretches of daily use when possible. People who need NSAIDs regularly are sometimes also prescribed a stomach-protecting medication to reduce ulcer risk. COX-2 selective NSAIDs like celecoxib were developed in part to address this problem, though they carry their own trade-offs.
Heart and Kidney Risks
All non-aspirin NSAIDs carry a cardiovascular warning. They can increase the risk of heart attack and stroke, particularly with long-term use or at higher doses. This risk applies to both over-the-counter and prescription NSAIDs. Aspirin is the exception here: at low doses, it actually protects against cardiovascular events, which is why some people take a daily 81 mg dose for heart health.
NSAIDs can also reduce blood flow to the kidneys. For most people taking an occasional dose, this isn’t a problem. But for anyone with existing kidney issues, or for people who are dehydrated or taking certain blood pressure medications, NSAIDs can push kidney function in the wrong direction. This is why people with kidney disease are generally told to avoid them.
Who Should Avoid NSAIDs
Pregnancy is a significant concern. The FDA recommends avoiding NSAIDs at 20 weeks of pregnancy or later because they can reduce amniotic fluid levels around the baby. After 30 weeks, the recommendation is to avoid them entirely. The one exception is low-dose aspirin (81 mg), which is sometimes prescribed during pregnancy for specific conditions like preeclampsia prevention.
People with a history of stomach ulcers or GI bleeding should be cautious, as NSAIDs can reactivate or worsen those conditions. The same applies to anyone with significant heart disease or impaired kidney function. If you take blood thinners, be aware that NSAIDs can amplify bleeding risk. There’s also a specific interaction worth knowing about: ibuprofen can interfere with low-dose aspirin’s blood-thinning effect if taken around the same time, potentially reducing aspirin’s protective benefit for the heart.
NSAIDs vs. Acetaminophen
Acetaminophen (Tylenol) is often grouped with NSAIDs in people’s minds, but it works differently and isn’t an NSAID. Acetaminophen reduces pain and fever but does very little for inflammation. If your pain involves swelling, like a sprained ankle, arthritis flare, or inflamed gums, an NSAID will address both the pain and the swelling while acetaminophen will only help with pain. On the other hand, acetaminophen is easier on the stomach and doesn’t carry the cardiovascular or kidney risks associated with NSAIDs, making it a better fit for some people.
For certain types of pain, combining an NSAID with acetaminophen can be more effective than either one alone, since they work through different pathways. This combination approach is now part of the ADA’s recommended strategy for managing dental pain.