Over-the-counter anti-inflammatories are a class of drugs called NSAIDs (nonsteroidal anti-inflammatory drugs) that reduce pain, swelling, and fever without a prescription. The three most common are ibuprofen (sold as Advil and Motrin), naproxen (sold as Aleve), and aspirin. They work by blocking the same enzyme in your body, but they differ in how long they last, who should take them, and what risks they carry.
How They Reduce Inflammation
When tissue is damaged or irritated, your body produces chemicals called prostaglandins that trigger swelling, pain, and heat at the site of injury. NSAIDs work by blocking the enzymes (called COX-1 and COX-2) responsible for making those prostaglandins. They physically prevent the raw materials from entering the enzyme’s active site, which slows down the entire inflammatory cascade. Classical NSAIDs like ibuprofen, naproxen, and aspirin are nonselective, meaning they block both COX-1 and COX-2 rather than targeting one over the other.
This is important because COX-1 also plays a protective role in your stomach lining and helps with blood clotting. Blocking it is what gives NSAIDs their well-known stomach side effects. COX-2 is more directly tied to inflammation and pain. Prescription-only selective COX-2 inhibitors were designed to spare the stomach, but some were pulled from the market due to cardiovascular risks.
The Three Main OTC Options
Each OTC anti-inflammatory has a slightly different profile in terms of duration, strength, and best use case.
Ibuprofen is the most widely used. It kicks in within about 30 minutes and typically lasts 4 to 6 hours, so you take it multiple times a day. The standard OTC dose is 200 to 400 mg per dose. It’s a good all-purpose choice for headaches, muscle pain, menstrual cramps, and minor injuries.
Naproxen lasts significantly longer, around 8 to 12 hours, which means fewer doses per day. This makes it a better fit for ongoing pain like arthritis or back pain where you want steady relief. Each OTC dose is typically 220 mg.
Aspirin is the oldest of the three and has a unique property: it irreversibly blocks platelets, which is why low-dose aspirin is used to prevent blood clots in people at risk of heart attack or stroke. As a pain reliever, it’s effective but carries a higher risk of stomach irritation than ibuprofen or naproxen at equivalent doses. Aspirin should never be given to children or teenagers, particularly during flu or chickenpox, because it’s linked to Reye’s syndrome, a rare but serious condition that causes dangerous swelling in the liver and brain.
Topical Anti-Inflammatories
Not all OTC anti-inflammatories come in pill form. Diclofenac sodium gel (sold as Voltaren Arthritis Pain) is a 1% topical gel available without a prescription. It’s specifically designed for arthritis pain in joints close to the skin’s surface, including knees, ankles, feet, elbows, wrists, and hands. You apply it up to 4 times daily on up to 2 body areas at once.
The advantage of a topical option is that far less of the drug enters your bloodstream, which reduces the risk of stomach and cardiovascular side effects. The tradeoff is that it works more slowly. Full pain relief can take up to 7 days of consistent use. If you don’t notice improvement after a week, it’s likely not the right approach for your situation.
Why Acetaminophen Isn’t an Anti-Inflammatory
People often group acetaminophen (Tylenol) with NSAIDs because they’re all in the pain relief aisle, but they work very differently. Acetaminophen blocks pain receptor signals and acts on the heat-regulating part of the brain to reduce fever. It does not treat inflammation. If your pain involves swelling, like a sprained ankle, a swollen joint, or inflamed tendons, acetaminophen won’t address the underlying cause. It only dulls the pain signal. For purely pain-driven conditions like tension headaches, either class works, but for anything with an inflammatory component, NSAIDs have the edge.
Stomach, Heart, and Kidney Risks
NSAIDs are safe for most adults when used at OTC doses for short periods, but they carry real risks that increase with higher doses and longer use.
The most common issue is gastrointestinal damage. Because NSAIDs block COX-1, they reduce the protective mucus lining in your stomach. This can cause anything from mild heartburn to stomach ulcers and serious bleeding. The risk is substantially higher in adults over 65, people with a history of ulcers, and those who drink alcohol regularly.
The FDA has strengthened its warning that non-aspirin NSAIDs can increase the risk of heart attack and stroke. This applies even to OTC doses and can occur as early as the first weeks of regular use, though the risk climbs with prolonged use. People with existing heart disease face a higher baseline risk.
Kidneys are the third area of concern. NSAIDs reduce blood flow to the kidneys, which is usually fine for short-term use in healthy people but can cause problems for anyone with kidney disease or dehydration.
Drug Interactions to Watch For
NSAIDs interact significantly with several common medications. If you take blood thinners like warfarin, adding an NSAID increases bleeding risk through two mechanisms: it interferes with platelet function and damages the stomach lining. One study found that the risk of hemorrhagic peptic ulcers was 13 times greater in adults over 65 taking both warfarin and NSAIDs compared to those taking neither.
People taking lithium for mood disorders should also be cautious. NSAIDs alter sodium balance in the kidneys, which can cause lithium to build up to potentially toxic levels in the blood. Blood pressure medications, particularly ACE inhibitors and diuretics, can also become less effective when combined with NSAIDs. If you take any prescription medication regularly, checking for interactions before reaching for an NSAID is worth the few minutes it takes.
Choosing the Right One
For occasional, short-term pain with inflammation, ibuprofen is the most versatile choice. It’s fast-acting and clears your system relatively quickly. If you need longer-lasting relief or you’re dealing with something chronic like arthritis pain, naproxen’s extended duration means less frequent dosing and more consistent coverage throughout the day. Low-dose aspirin is generally reserved for cardiovascular prevention rather than pain relief, since the other two options handle pain with fewer stomach issues.
For localized joint pain, especially in the hands, knees, or ankles, topical diclofenac gel lets you target the specific area while minimizing the systemic side effects that come with pills. Combining oral and topical NSAIDs isn’t recommended, since both contribute to the same overall drug load in your body. Whichever option you choose, using the lowest effective dose for the shortest time needed is the simplest way to get the benefits while keeping the risks low.