Hi Sharon,

No there has not been a study stating long term use of DN has a negative impact.  the fact is needling triggers many physiologic responses in the body that do not fatigue or "get used to" as triggering these responses happen no matter what that stimulus i.e trauma, illness or dry needling so it is unlikely there would a negative result with longer term use.  That said if DN is not working or the effects lasting it may not be the right treatment choice or applied in the wrong place or technique.  We do see this a lot with traditional dry needling teaching and application- you can get to the point but miss the system!

Frank