Yes, that's normal, it does hit you quickly. My diabetic friends are always concerned about getting the right dosage before a meal because obviously if they miscalculate and give themselves too much, their blood sugar will crash, and they always inject right before they eat. It can be worrisome if they aren't able to get to eat immediately after because they take far more on average than a bb'er does. One guy I know has taken 40 units at one time.