American Diabetes Association answered:
You may get better coverage by splitting your one shot of insulin into two shots. These can be given in the morning and in the evening. Usually, for twice-daily injections, you’ll use intermediate-acting or premixed insulin instead of long-acting insulin. The morning shot will be a bigger dose than the evening shot.
However, even with this plan, you may have a period in the early morning, between 3 and 10 a.m., when your insulin level may be low.
Another possibility is to take a combination of insulins. You can take rapid-acting or regular insulin along with your morning shot of intermediate-acting NPH (neutral protamine Hagedorn) insulin. This gives you a bolus of insulin to cover your breakfast meal. Additional insulin can be taken later in the day. You can either use premixed insulins or mix two types of insulin in one injection.
Some people choose to take a basal, long-acting insulin analog once daily and a mealtime rapid-acting insulin analog up to three times a day, rather than NPH and rapid-acting insulin.
It may take a little experimenting and consulting with your health care team to figure out how to best mix rapid-acting or regular and intermediate-acting insulins. You may have to change the ratio many times before you get the results that best suit you.
You may find it convenient to buy premixed insulin, such as a 70/30 or 75/25 mixture, or you may prefer to split and mix the doses yourself. Mixing the doses yourself gives you the flexibility to match your insulin dose to your insulin needs. This may be helpful when you are trying to account for your physical activity and meals.You may get better coverage by splitting your one shot of insulin into two shots. These can be given in the morning and in the evening. Usually, for twice-daily injections, you’ll use intermediate-acting or premixed insulin instead of... More