There is an initial time period where you body is building up it's carnosine levels. Depending on how much you take and also how (Carb's were found to increase uptake) you will establish your levels quicker. The tingling is a good way to measure how much your body needs in my experience. I usually split it into two doses, and when I feel the tingle I know that my dose is enough and then scale it down just a tad. I find my maintenance is 2g x2 daily.
To me the paresthesia feels like very dry skin, which is what I mistook it for at first!