PlainMeds guide
NSAIDs and Acetaminophen
How FDA labels distinguish common over-the-counter pain-relief categories and warnings.
FDA labels place ibuprofen, naproxen, and aspirin in the NSAID category, while acetaminophen is an analgesic and antipyretic. Their label warnings and interaction records differ.
This registry summarizes FDA-label categories, warnings, and interaction records for common over-the-counter pain-relief products. It does not select a medicine, dosage, or treatment plan for an individual.
- NSAIDs: ibuprofen, naproxen, and aspirin share an FDA drug-class category.
- Acetaminophen: FDA labeling treats it as an analgesic and antipyretic rather than an NSAID.
- Warnings: each product label records contraindications, interactions, and dose-specific cautions.
- Boundary: PlainMeds does not turn those records into a medicine-selection or dosing recommendation.
| Feature | Ibuprofen (Advil, Motrin) | Naproxen (Aleve) | Aspirin (Bayer) | Acetaminophen (Tylenol) |
|---|---|---|---|---|
| Drug Class | NSAID | NSAID | NSAID | Analgesic / Antipyretic |
| Pain Relief | Strong | Strong | Moderate | Moderate |
| Anti-Inflammatory | Yes | Yes | Yes | No |
| Fever Reducer | Yes | Yes | Yes | Yes |
| Duration | 4–6 hours | 8–12 hours | 4–6 hours | 4–6 hours |
| Stomach Risk | Moderate | Moderate | Higher | Low |
| Kidney Risk | Yes | Yes | Yes | Low |
| Liver Risk | Low | Low | Low | Yes (at high doses) |
| Label warning type | Alcohol-related caution | Alcohol-related caution | Alcohol-related warning | Alcohol-related warning |
NSAIDs: How They Work
NSAIDs (Non-Steroidal Anti-Inflammatory Drugs) work by blocking enzymes called COX-1 and COX-2. These enzymes produce prostaglandins, chemicals that promote inflammation, pain, and fever. By blocking prostaglandin production, NSAIDs reduce all three.
The downside is that prostaglandins also protect the stomach lining and help maintain kidney blood flow. That's why NSAIDs can cause stomach irritation and shouldn't be used long-term without medical supervision.
Acetaminophen: How It Works
Acetaminophen's exact mechanism isn't fully understood, but it appears to work primarily in the central nervous system rather than at the site of inflammation. This is why it relieves pain and reduces fever but does not reduce inflammation or swelling.
Because it doesn't affect prostaglandins in the stomach or kidneys, acetaminophen is generally gentler on the digestive system. However, it is processed by the liver, so taking too much (or combining with alcohol) can cause serious liver damage, which is why the FDA caps single-ingredient adult dosing and limits acetaminophen in combination products.
Label categories, not treatment selection
Headaches & Migraines
FDA labels describe analgesic and antipyretic effects for several over-the-counter products. They do not establish a universally appropriate product for a particular person's headache or migraine.
Muscle & Joint Pain
NSAID labels describe anti-inflammatory effects and product-specific warnings. The registry records those distinctions without choosing a product for joint or muscle pain.
Dental Pain
FDA labeling records analgesic and anti-inflammatory information for these products. Dental-pain treatment, including any combination of medicines, is outside this registry's scope.
Fever
Several products carry label information related to fever reduction. Age, pregnancy, contraindications, and product selection are not determined by this registry.
Menstrual Cramps
NSAID labels describe prostaglandin-related mechanisms. PlainMeds does not translate that mechanism into timing, selection, or use instructions for menstrual symptoms.
Label warnings and source records
FDA over-the-counter labels list product-specific warnings, contraindications, active ingredients, and interaction information. Those records vary by product and formulation. PlainMeds links the facts in its drug database and does not publish worked treatment cases, dose schedules, combination plans, or a list of people who should choose or avoid a medicine.
Browse labeled interaction records
The interaction database lists FDA-label pair records and source links.
Check Interactions →Medications covered in this guide
Open any medication for its full FDA profile: labeled uses, side effects, interactions, recalls, and pricing.