Is duloxetine a fast acting drug?

Hi, Tam!
No, it is not and you won’t get instant relief. It’s not a narcotic or opioid.
Most people will begin to feel the benefits within the first two weeks or so but it can take 4-6 weeks to feel the full effects.
It’ll be worth it…

This drug "duloxetine" (i.e., brand name "Cymbalta") [P,S,. Both almost identical - check with doctor or pharmacist for specific details?] This is an excellent drug, with nearly no side-effects, but unfortunately it doesn't work for everyone, potentially due to it being used for several medical maladies, and the reason that it's being prescribed for! In addition, some people report that it is hard to discontinue, although that was not an issue for myself. Another thought, sometimes a "muscle relaxer" can be just as effective, and less overbearing for your body (i.e., impacting your body in ways that you do not treatment for (Ex. anxiety issues, etc,), if being used for "Peripheral Neuropathy" in your case? Good luck.