Since no one answered I wanted to come back and answer myself for anyone else who may have this problem. The tingly/prickly sensation lasted off and on for about two weeks (though I still feel it every now and then). I only took two doses (400mg) before I noticed this symptom and my doctor had me stop. This medicine is no joke. I urge you to see and naturopath and try holistic remedies before taking this. It's not worth the possible nerve damage and other side effects.