Managing type 2 diabetes hinges on good blood sugar control. One way to know if your blood sugar is well-controlled is by looking at your A1C level, which shows your average blood sugar levels over the last two to three months.

You’ve tried changing your diet and getting more exercise, and you’ve been taking oral drugs like metformin (Glucophage). If your A1C levels still haven’t budged, insulin might be the next best step to bring them into a healthy range.

Read the infographic below to learn what questions to ask your doctor as you start insulin therapy.

10 questions to ask your doctor about insulin

Most people with type 2 diabetes aim for an A1C target of less than 7 percent.

Depending on how long you’ve had diabetes and whether you have other health risks, your target might be stricter (6.5 percent) or looser (8 percent).

You’ll only get an A1C test at most every three months, but you also need to know how your blood sugar levels fluctuate from day to day if you’re using insulin.

Testing your blood sugar daily — before meals and at bedtime — can help you judge how well your insulin is working, and whether your doctor needs to adjust your dose.

Insulin comes in four types. Each type takes a different amount of time to start working, gets to a peak or highest level, and lasts for a different amount of time in your body.

  • Rapid-acting insulin starts to work about 15 minutes after injection. It peaks between 30 minutes and 3 hours and keeps working for 3 to 5 hours.
  • Short-acting insulin takes about 30 to 60 minutes to start working. It peaks between 2.5 and 5 hours and is effective for 4 to 12 hours.
  • Intermediate-acting insulin starts to work in 1 to 2 hours. It peaks between 4 and 8 hours, then lasts for 12 to 18 hours.
  • Long-acting insulin takes several hours to start working. It doesn’t have a peak and can keep working for 24 hours.

You might need to combine different types of insulin to get the best results.

Your doctor will figure out your insulin dose based on factors like your weight and blood sugar levels.

Most people with type 2 diabetes only need to inject insulin once a day — often at dinnertime or bedtime.

If your blood sugar isn’t well-controlled, you might need to increase to two or more injections a day.

Insulin helps bring down your blood sugar after you’ve eaten foods containing carbohydrates.

Ask your doctor how many units of insulin you’ll need to take to balance out the carbohydrates you eat, and when to take it in relation to meals. Often when you’re starting to use insulin after taking oral medications, you’re just using a long-acting insulin once a day. So you may not be balancing carbs directly.

If your blood sugar levels are high day after day, your doctor might need to adjust the timing or dose of your insulin.

Even if insulin is keeping your blood sugar under good control, other factors in your life can cause a temporary spike in your levels.

Exercise, illness, and stress can all influence blood sugar levels.

Many of the oral diabetes drugs, like metformin, are helpful even after starting insulin, so doctors often recommend they be continued. Others may need to be stopped if they drop sugar levels in combination with insulin. If insulin alone doesn’t control diabetes within about three months, your doctor might add an oral diabetes drug to your insulin therapy.

Consistently high blood sugar can damage organs and tissues throughout your body.

Complications of uncontrolled diabetes include:

  • cardiovascular disease
  • nerve damage
  • kidney damage
  • blindness
  • foot infections
  • skin conditions

If insulin doesn’t bring down your A1C levels, it’s time to talk to your doctor about other treatment options.