If you go to Amazon and search for "a1c test" (by pts Diagnostics), the pack of twenty is cheapest per test. You will also need a pack of disposable lancets, a finger lancing device. You will also optionally alcohol swab to sanitize your finger without contaminating it, but soap and water work too. Remember to shake it well when testing, otherwise the result is an error. Always discard the lancet after use. You need to test only once every 1-3 months. Refrigerate everything, but let it warm to room temperature before testing. If I remember correctly, the result number is like an exponential moving average over about three months. If you're in the prediabetic range, things like avoiding high-AGE foods, processed carbs, and red meat should help bring it down, as should consuming ceylon cinnamon, flaxseed, and berberine. Of course cardio also will easily bring it down. Every factor contributes in the ballpark of 0.1, so one needs a lot of changes to gradually bring it down into an optimal zone.