What to Ask Your Doctor About Insulin

Has your doctor prescribed insulin to help manage your type 1 or type 2 diabetes? You’ll want to know how and when to take it, what side effects could happen, and what other changes you may need to make.

Use this list of questions as a starting point when you talk with your doctor.

What type of insulin do I need?

Insulin comes in four basic forms:

  1. Rapid-acting insulin starts to work within 30  minutes after injection. Its effects only last for 3 to 5 hours.
  2. Regular- or short-acting insulin takes about 30 minutes to work and lasts up to 12 hours.
  3. Intermediate-acting insulin takes up to 4 hours to work fully. It peaks anywhere from 4 to 12 hour, and its effects can last for up to 24 hours.
  4. Long-acting insulin begins to work in about 4 hours and then lasts up to a full day without a real peak

Your doctor can tell you which type will work best with your diabetes type and blood sugar level.

How should I give myself insulin?

You can inject or inhale it.

To inject insulin, you can use a syringe, pen, or pump. There is also a needle-free option called a jet injector. Pens are easiest to use, pumps deliver insulin continuously, and syringes are the least expensive.

Find out how many times a day you'll need to inject, and how much insulin to inject in each dose. If you use an insulin pump, ask your doctor when you'll need to give yourself an extra amount of insulin (bolus).

If you have type 1 diabetes, you may need up to three or four injections daily. People with type 2 diabetes may need just one shot of insulin a day, possibly increasing to three or four injections.

There is also a rapid-acting inhaled insulin that you can use before meals only. If you have type 1 diabetes, you must also use long-acting insulin.

Talk with your doctor about the pros and cons of each method. The decision may come down to cost, so find out which method your insurance will cover. If you don't have insurance or your plan won't pay for the type of insulin delivery method you prefer, ask your doctor about programs that can help you cover the cost.


When should I take my insulin?

There isn’t one simple answer to this question. It depends on things such as:

  • The type of insulin you use (fast-acting, premixed, etc.)
  • How much and what type of food you eat
  • How much exercise you get
  • Other health conditions you have
  • The type of insulin delivery system (such as shots, pump, or inhaler) you use

Your doctor may want you to take insulin a half-hour before meals, so it's available when sugar from food enters your bloodstream. Find out exactly when during the day you need to take each of your injections, and what to do if you forget to give yourself an injection.

If I inject insulin, does it need to be in a certain part of my body?

Most people inject it into their belly, since it’s easy to reach. Your insulin shot will work fastest if you inject it into your stomach. (Be sure to stay at least 2 inches from the belly button.) You can also inject insulin into your arms, thighs, or buttocks.

Ask your doctor or diabetes educator to show you the right way to inject, including how to keep your needle and skin clean to prevent infections. Also learn how to rotate the injection site so you don't develop hard, fatty deposits under the skin from repeated injections.

Does insulin affect other medicines I take?

Some drugs can intensify low blood sugars caused by insulin. Tell your doctor about all the medicines you take, even those you bought without a prescription.

What can I eat while taking insulin?

Ask your doctor for food recommendations to help your insulin work best. For instance, you’ll want to know how much to eat at each meal, which types of foods are best for you to eat, whether you need to have snacks, and when you should eat. If you drink alcohol, ask your doctor if that’s OK while you’re taking insulin, and what your limit should be.

What is my target blood sugar level?

Your doctor should tell you how often you need to check your blood sugar using your blood glucose meter. Find out your target blood sugar range before and after meals, as well as at bedtime. For most people with diabetes, the targets are:

  • 70 to 130 milligrams per deciliter (mg/dL) before meals
  • Less than 180 mg/dL 2 hours after a meal


Ask what to do if your blood sugar doesn’t stay within range, and how often you need to have your A1C level tested.

What side effects could I have from the insulin?

The most common side effects are low blood sugar and weight gain. Ask your doctor what others you might have, and what to do if you get them.

How should I store my insulin?

Most insulin makers recommend storing it in the refrigerator, but injecting cold insulin can be uncomfortable. Make sure it’s at room temperature before injecting. Ask your doctor whether to store your insulin in the fridge or at room temperature. Also find out how long your insulin will last, and how to tell if it has gone bad.

Can I reuse syringes?

Doing so can lower your costs, but it is not without risk. Ask your doctor if that’s safe for you, and how to keep your syringes clean so you don’t get an infection. If you throw out your syringes after each use, ask how to safely dispose of them.

Questions Your Doctor Might Ask You

  • How do you feel while taking your insulin?
  • Have you noticed any side effects?
  • How are you responding to your insulin dose? Are you having any problems with high or low blood sugar?
  • Have you had any trouble using your insulin syringe, pen, or pump?
  • Do you know how to store and dispose of your used syringes or needles?

If you have any questions between doctor visits, write them down so you remember to ask them next time. Your doctor can check on your progress so that you can successfully manage your diabetes.

WebMD Medical Reference Reviewed by Melinda Ratini, DO, MS on July 30, 2016



Vivian Fonseca, MD, FRCP, chief, Section of Endocrinology, Tulane University School of Medicine; president, Medicine & Science, American Diabetes Association.

American Diabetes Association: "Insulin Basics;" "Insulin Routines;" and "Insulin Storage and Syringe Safety."

National Institute of Diabetes and Digestive and Kidney Diseases: "What I need to know about Diabetes Medicines."

U.S. Food and Drug Administration: "Insulin."

News release, FDA.

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