Do nsaids stop working well after taking them for so long?

Dependency : drug dependency . Anyway NSAIDs are short term fix as long term could induce GI bleeding.

Indubitably!: Yes, after a while the body adjusts to the presence of that chemical. It's called "tolerance." The body begins to respond less well to the medication. Unfortunately, you can only take so much of the NSAID's or risk kidney and/or liver damage. Sometimes changing to another NSAID will help, or adding/changing to another medication. Also, depending on what you have, forms of physical therapy can help