Question 1

Why does naproxen take longer to work than ibuprofen?

Accepted Answer

Naproxen has a slower absorption rate (peak at 2-4 hours vs 1-2 for ibuprofen) and longer half-life (12-17 vs 2-4 hours). This trade-off means slightly slower onset but much longer duration of action per dose.

Question 2

If I take naproxen at 8am, when will it stop working?

Accepted Answer

Significant pain relief typically lasts 8-12 hours, so until 4-8pm. Some effect may continue up to 14 hours. For 24-hour coverage with arthritis, a second dose is usually taken 12 hours after the first (at 8pm).

Question 3

How long after stopping naproxen is it completely out of my system?

Accepted Answer

It takes 4-5 half-lives for complete elimination: approximately 2.5-3.5 days for most people. For elderly or those with kidney issues, it may take 4-6 days to be completely cleared from your system.

Question 4

Can I take naproxen twice a day even though it lasts 12 hours?

Accepted Answer

Yes, twice-daily dosing (every 12 hours) is standard for chronic conditions. The effects overlap slightly, providing continuous 24-hour coverage. This maintains steady drug levels for consistent inflammation control.

Question 5

Why does naproxen work faster for some people than others?

Accepted Answer

Individual variation depends on genetics (CYP2C9 enzyme activity), whether taken with food, formulation type, gastric emptying rate, and the specific pain condition being treated. These factors can alter onset by 30-60 minutes.