The Healing Handbook for Persons with Diabetes

Professor B and his Bottle of InsulinChapter 8: Insulin

Insulin Basics 

If you have Type I (insulin dependent) diabetes, your body produces no insulin, and you must receive insulin by injection. If you have Type II (non-insulin dependent) diabetes you may need insulin injections, if your diabetes cannot be brought under control with proper diet, exercise, and oral medication. Remember that insulin can never be taken by mouth because it is protein that would be broken down during digestion.

Insulin is measured in units. The unit is a measure of weight: 24 units = 1 mg. "U100" insulin is called that because there are 100 units of insulin in 1 cc of solution. There are 1000 units in a bottle of U100 insulin. You must inject U100 insulin with U100 insulin syringes.

Types of Insulin 

Your insulin is either beef, pork, beef and pork combined, or human. This is the species of your insulin and is indicated on the label of your insulin bottle.

Human insulin is genetically engineered from E. coli bacteria ('Humulin," made by the Eli Lilly Company) or yeast ("Novolin," made by the Novo Nordisk Company). Human insulin now accounts for the majority of all the insulin used. It will replace all animal insulins in the near future.

Types of insulin include Regular, Semi-Lente, NPH, Lente, Ultralente, and the new "insulin analog" called Lispro. Semi-lente is seldom used. The important characteristics of each type of insulin are:

  • When it starts to work (onset)
  • When it works hardest (peak activity)
  • How long it lasts (duration)

Many factors such as species, injection site, and exercise level affect the onset, peak, and duration of insulin.

Regular insulin (pork, beef, beef/pork, or human) is fast acting and lasts a short time in the body. It is used before meals to control the post-meal rise in blood sugar, and to lower blood sugar quickly when an immediate correction is needed.

Semi-Lente insulin (beef/pork) has a short duration, but twice as long as Regular insulin. It is sometimes used to control post-meal rises in blood sugar and may be combined with Lente insulin.

NPH insulin (beef, pork, beef pork or human) contains added protamine for an intermediate-acting effect. NPH insulin provides a basal amount of insulin. Two injections a day are usually prescribed.

Lente insulin (beef, pork, or human) contains added zinc, which gives it an intermediate-acting effect similar to NPH. Lente insulin also provides a basal amount of insulin. Two injections a day are usually prescribed.

Ultralente insulin (beef or human) contains a lot of added zinc to give it the longest-acting effect. Note that Humulin Ultralente has a shorter peak and duration than beef Ultralente. Ultralente insulin provides the steadiest basal amount of insulin. One injection a day is used in combination with Regular insulin before meals. 

Insulin Lispro, sold under the trade name Humalog, is a new man-made insulin that is very similar to naturally occurring human insulin. It has a more rapid onset and a shorter duration of action than human regular insulin. It is meant to be taken within 15 minutes of eating a meal and in combination with longer-acting insulin. The Diabetes Monitor has made additional information about Insulin Lispro available online. The University of Massachusetts Diabetes Clinics have found this new insulin to be helpful for many persons who need to take a short-acting insulin before meals but who have difficulty with meal schedules or with after-meal insulin reactions.

70/30 Insulin (human) is a mix of 70% NPH and 30% Regular insulin. Two injections a day are usually recommended.

This table summarizes the different kinds of human insulins and how they act. These exact numbers are for the "Humulin" brand of human insulin, but numbers for "Novolin" brand insulins are similar.

Human Insulin Activity

Type  Onset  Peaks  Duration 




Lispro (Humalog)


30-60 minutes

2-4 hours

3-4 hours

6-10 hours

Less than 15 minutes

15-30 minutes

2-3 hours

4-10 hours

4-12 hours

minimal peaking

30-90 minutes

2-3 hours & 8-12 hours

4-6 hours

14-18 hours

16-20 hours

20-30 hours

Less than 5 hours

18-24 hours

Source: Eli Lilly, Company.

Your Injection Schedule 

Follow the schedule of insulin injections prescribed by your health-care provider. Your injection schedule is precisely matched to your activity and blood glucose levels, diet, and the type of insulin you use, so follow it exactly.

My insulin type: _______________________________________________________
Species: ______________ When I take it: __________________________________
Amount: ____________________________________________________________

Correcting High Blood SugarWith Regular Insulin

Regular insulin is fast acting and usually recommended as a supplement to correct high blood sugars. The exact amount depends on how high your blood sugar is and how you usually respond to Regular insulin. A child or thin adult may be able to lower blood sugar with 1 unit of Regular insulin. A larger adult, or a person on large doses of insulin may need 2 to 4 units. Consult with your diabetes educator or doctor about handling high blood sugar.

Add _____ units for a blood sugar over _____ mg.

Permanent Insulin Adjustments 

You can help in the process of achieving control of your diabetes by watching for high and low blood sugar patterns and keeping track of them as part of your overall blood glucose monitoring routine. A pattern occurs when your blood sugar is in a certain range at the same time of day for three consecutive days. For example:

Blood Glucose Level
Day  Morning  Noon  Afternoon  Bedtime 



179 mg

166 mg

209 mg

136 mg

129 mg

145 mg

97 mg

84 mg

92 mg

147 mg

141 mg

159 mg

Although the numbers are different each day, you can see a pattern. Morning blood sugars are all over 150 and afternoon blood sugars are all under 100. In this case, your health-care provider might recommend an increase in evening NPH (or Lente) insulin to lower your blood glucose in the morning.

When your blood glucose level fluctuates, try to identify the cause of the high or low blood glucose measurement. There are only three causes of fluctuations in blood sugar level: changes in DIET, EXERCISE, or INSULIN. But there are multiple reasons a fluctuation may occur.

Common Reasons for Blood Sugar Fluctuations 

  • Changes in exercise or activity level
  • Snacks added or omitted
  • Delayed meals, or a change in the type of amount of food eaten
  • Illness or infection
  • Alcohol consumption
  • Insulin injected into a lumpy area or an exercising arm or leg
  • Over-treatment of an insulin reaction
  • Skipped insulin injection

Adjusting Your Own Insulin According to Patterns 

Your diabetes educator can help you learn how to adjust your own insulin doses according to high and low blood sugar patterns. Here are the steps:

  1. Once you have observed a pattern of high or low blood sugars at the same time on three successive days, determine what insulin should be working at that time. Consult the Insulin Summary chart earlier in this chapter for information on insulin peak times and durations.
  2. Adjust your dose of that insulin only by 1-2 units:
    Increase insulin for high blood sugar
    Decrease insulin for low blood sugar
    Change only one type of insulin at a time. 
  3. Check the effect of your insulin adjustment for 3 days before making another adjustment.

This diagram summarizes the steps:

Steps to take for adjusting your insulin. Click for a larger image. 

Buying Insulin

Insulin prices vary according to purity and source. Pure pork insulin and human insulin tend to lower blood sugar more effectively than beef or beef/pork insulin in some people. Be sure you buy the insulin your doctor prescribes, and do not change brands or species without checking with him or her

Storing Insulin

You may keep opened bottles of insulin at room temperature (less than). Insulin deteriorates only when exposed to temperature extremes, so don't leave it on a sunny window sill or in the freezer.

Store unopened bottles in the refrigerator, and rotate your supply, so that you use the oldest bottles first.


Also, keep a good supply of syringes, needles, and alcohol wipes.

  • Before injecting insulin, always check the expiration date on the bottle. DO NOT USE INSULIN AFTER THE EXPIRATION DATE.
  • If insulin is exposed to freezing temperatures, or temperatures above 85 Farenheit or 30 Celsius, THROW IT AWAY.
  • If insulin contains small, hard, white particles that do not mix, THROW IT AWAY.
  • If insulin sticks to the bottle, creating a frosted appearance, THROW IT AWAY.


Injection sites include the abdomen, outer upper arms, the thighs, buttocks, or hip areas. Do not inject insulin near bony places or joints. Do not give injections closer than 1 inch apart. Insulin absorption can vary from site to site. The best absorption site is the abdomen. In the past it was important to rotate (change) the insulin site daily to prevent building up lumpy areas. With newer, purer insulins, this is less of a problem. Follow your diabetes educator's advice on injection sites.

Where to Inject Insulin 

Preparing for Injection

  • Steps for preparing your syringe differ, depending on whether you use one type of insulin or a mixture of two or more insulins.

If you use one type of insulin:



Wash your hands.

Turn the insulin bottle on its side and roll it between your palms to mix it, but DO NOT SHAKE IT.

Wipe the top of the insulin bottle with an alcohol wipe. CLICK the picture to see a video (0.7 megabytes)! 
Preparing the insulin bottle. 

Pull plunger to draw in enough air to equal your insulin dose: _____ units.

Push the needle through the bottle top and inject air into the bottle.
Steps 4 and 5 

With the needle in the bottle, turn it upside and pull the plunger to fill the syringe past your dose of insulin.

Push slowly to the line of your correct dose of insulin: _____units.

Steps 6 and 7 
8. Check for air bubbles. If bubbles are present, tap the syringe to make them rise. Then repeat steps 6 and 7 and check for bubbles again.

Continue repeating steps 6 and 7 until no air bubbles are present.

Step 8 
9. Remove the needle from the bottle, and carefully rest the syringe so that the needle touches nothing.

If you use more than one type of insulin:



Wash your hands.

Wipe the tops of both insulin bottles with an alcohol wipe.

Turn the NPH or Lente insulin bottle upside down and roll between your hands to mix, but DO NOT SHAKE IT. 

Steps 1 to 3 


Pull plunger to draw in enough air to equal your NPH or Lente insulin dose: _____ units.

Push the needle through the top of the NPH or Lente insulin bottle and inject air into the bottle.

Remove empty syringe and needle from bottle.

Steps 4 to 6 

Pull plunger to draw in enough air to equal your Regular insulin dose: _____ units.

Push the needle through the top of the Regular insulin bottle and inject air into the bottle.

Steps 7 and 8 

With the needle in the bottle, turn it upside and pull to fill the syringe past your dose of Regular insulin.

Push slowly to the line of your correct dose of insulin: _____units.

Steps 9 and 10 
11. Check for air bubbles. If bubbles are present, tap the syringe to make them rise. Then repeat steps 9 and 10 and check for bubbles again.

Continue repeating steps 9 and 10 until no air bubbles are present.

Step 11 
12. Remove the needle from the bottle with Regular insulin in the syringe.
13. Push the needle through the top of the NPH or Lente insulin bottle and carefully pull plunger back to your total dose of insulin: _____ units units NPH or Lente + _____ units Regular). Step 13 
14. Remove the needle from the bottle, and carefully rest the syringe so that the needle touches nothing.



Choose your injection site.

Wipe the area with alcohol to clean it.

Wipe the site! 

Grasp a large pinch of skin between your thumb and fingers.

Push the needle straight into the skin.

Pinch and push! 
5. Press the plunger in. Press the plunger in! 
6. Holding the alcohol wipe next to the injection, pull out the needle. Wipe the area with the alcohol wipe. Remove the needle and wipe. 

Allergic Reactionsand Other Mild Reactions

Occasionally, you may notice a small, hard red area at the injection site. It may also itch. This is a mild allergic reaction that will go away in a day or so. A more generalized allergy to insulin causes hives and itchy skin over other parts of the body. Usually, this disappears by itself. If the itching continues, consult your doctor.

  • Insulin Edema (swelling) may develop when you start insulin therapy. It is usually not severe. You may notice swelling in your legs, ankles, feet, hands, or face. This will go away in a few weeks.
  • Lipohypertrophy is the formation of scar tissue in an area that has been used repeatedly for injection. A firm, lumpy area develops. Insulin absorption is changed in this area. This condition is seldom seen with the use of human insulins and pure pork insulins.
  • Lipoatrophy is the term used to describe the "pitted" areas that may form at injection sites. This condition, now rare, resulted from loss of fat in the area due to repeated injections with impure insulins.

Syringes and Needles 

Disposable insulin syringes with needles are convenient. You can use them more than once If You Take Care To Keep The Needle Clean. With repeated use, however, the needle becomes dull, the unit lines may wear off, and you may have trouble drawing an accurate dose.
The newest needles are lubricated and very small (1/2 inch to 5/8 inch long and 28 to 29 gauge) to minimize discomfort. All syringes are U100 and intended for use with U100 insulin. Syringes hold 25 units, 30 units, 50 units, or 100 units.

Some Brand-Name Syringes

Brand 100 Units 50 Units 30 Units 25 Units
1 cc
1 cc
1 cc
1/2 cc

3/10 cc
1/4 cc

1/4 cc

Novolin Pen Injector 

This pen-shaped device holds prefilled cartridges of NPH, Regular, or 70/30 insulin. The pen is convenient and easy to use: you screw a needle onto one end, dial the dose, and then inject. This highly portable injection device is ideal for people on intensive insulin therapy, or those who are away from home at meal times. Prices for the Novolin Pen Injector vary greatly, so watch for sales.

Disposing of Needles and Syringes

The improper disposal of syringes and needles is illegal and hazardous. You must obtain a sharps container specifically designed for the containment of syringes and needles. When filled, the container can be returned to the medical supply center where you purchased it. You may also use a mail back system which supplies sharps containers. Call 1-800-723-3863 for this service.

The Insulin Pump

This sophisticated device uses computer chip technology, a syringe reservoir, and battery power to deliver insulin to your body automatically. The syringe is filled with buffered Regular insulin, Velosulin or Humulin BR, and is connected to a thin plastic tube called an infusion set. At the end of the infusion set is either a needle or a catheter (a l/2-inch plastic tube inserted with a needle; the needle is removed after insertion, leaving the catheter in place).

The pump is worn 24 hours a day, on a belt, in a pocket, attached to a bra, or in a special leg pouch. During bathing and swimming, the syringe is removed from the pump, or the tubing may be disconnected from the syringe and capped. The size is approximately 2" by 3" by 5/8".

The object of pump therapy is to mimic the action of normal beta calls. The pump delivers both a basal rate and bolus doses. Basal rate refers to the preprogrammed continuous delivery of 0.1 unit increments of insulin. Bolus doses are larger doses programmed in before meals and snacks. Insulin doses are based on blood glucose test results, but the pump does not have a glucose sensor, so the wearer must test blood glucose levels 4 to 8 times daily -- and sometimes at 3 am. He or she must interpret blood glucose levels, taking into consideration everything that may affect blood glucose, and then decide on an appropriate insulin dosage.

This is a great responsibility. Pump wearers must be highly motivated, able to operate the pump, willing to test blood glucose frequently, and astute enough to know when a problem is developing. They must also have access to a health-care team familiar with pump therapy.

How do I know if the insulin pump might be right for me?

Consider the advantages and disadvantages:


  • Greater flexibility of meals, exercise, and daily schedule
  • Improved physical and psychological well being
  • Smoother control of blood glucose level
  • Lower glycosylated hemoglobin


  • Risk of infection
  • More frequent hypoglycemia
  • Constant reminder of diabetes

Additional Information

  • Additional information is available from your physician and the diabetes education staff where you receive your medical care.
  • Additional online information is available from the manufacturers of pumps, including MiniMed Technologiesand Disetronic Medical Systems.

Insulin Reactions

Normal blood glucose levels fall between 60 and 120 mg/dl. When you have an insulin reaction, your blood sugar may fall below 60 mg/dl, or fall rapidly from a high level to a lower level, or simply fall below your usual level. This is called low blood sugar or hypoglycemia (hypo = too little, glyc = sugar, emia = blood). An insulin reaction can occur if you:

  • Inject too much insulin
  • Skip a meal, eat too little, or wait too long between meals
  • Exercise or work more than usual

An Insulin Reaction Symptoms of an Insulin Reaction 

When you have an insulin reaction, the symptoms come on suddenly:

  • Cold sweat and a clammy feeling
  • Dizziness, weakness, or shakiness
  • Irritability or impatience
  • Pounding heart or increased heart rate
  • Nervousness or confusion
  • Headache
  • Blurred or double vision
  • Hunger
  • Numbness or tingling in lips or fingertips
  • Paleness and slurred speech
  • Convulsions

An insulin reaction is your body's response to low blood sugar. When your brain senses low blood sugar, it signals the release of hormones called catecholamines. One such "catecholamine" is adrenaline!

Catecholamines produce the effects of pallor, sweating, shaking, pounding heart beat, nervousness, and irritability.

Catecholamines also cause the release of stores of sugar in the liver (glycogen), which raises your blood sugar.



  1. Take some kind of FAST SUGAR FOOD to raise your blood sugar quickly.
Fast Sugar Foods 



Here are some that are easy to find:

From the Drug Store:

Insta-Glucose (1 tube)

Glutose (1/3 bottle)

Glucose tablets (2-3)

Destrasols (4-6)

Monoject Insulin Reaction Gel (1 packet)

From the Grocery Store:

Life-Saver Candies (4-6)

Cola or other soda (6 oz.)

Chuckles Candy (2)

Honey or corn syrup (2 tbsp)

Orange Juice (4 oz.)

Jelly beans (6)

Sugar (2 lumps)

2. Stop what you are doing and sit or lie down.

3. Wait 10 to 15 minutes. If you do not feel better, repeat the food taken.

DO NOT OVER-TREAT A REACTION by continuing to eat until it goes away, or by eating anything and everything in sight.

4. When you feel better, eat a snack. If it is close to a meal time, have your next meal.

Sample Snacks for After a Reaction

  • Packaged peanut butter cracker sandwiches (4)
  • A piece of fruit and a glass of milk (8 oz)
  • 4 crackers and a glass of milk (8 oz)
  • 1/2 cheese sandwich

After a reaction, you may feel tired and have a high blood sugar. DO NOT MAKE A PERMANENT CHANGE IN YOUR INSULIN DOSE AT THIS TIME. If you have frequent insulin reactions at the same time of day, you may need to adjust food or insulin. See your diabetes educator or doctor. Keeping a record of blood sugar tests, insulin doses, insulin reactions, and how you feel will help your diabetes educator or doctor make adjustments.

Preventing Insulin Reactions 

To prevent insulin reactions:

  • Eat regular meals on schedule
  • Avoid sudden changes in diet, exercise, or insulin
  • Eat a snack before exercising

To prevent additional problems when you have a reaction:

  • Always carry a fast-acting sugar food
  • Treat reactions immediately
  • Wear diabetes identification to inform others of your condition in case of an accident or loss of consciousness due to a reaction

A Medic Alert Bracelet 

Teach your family, friends, teachers, and coworkers how to spot a reaction and how to help if you have one. If you ignore reaction warning symptoms and do not take sugar, you could become unconscious. While this is unlikely, you can protect yourself by teaching family and friends how to give a glucagoninjection in an emergency (see instructionsbelow).


When a friend or family member has an insulin reaction, don't panic. If you keep a clear head and act quickly to give them sugar, you can stop the reaction before more serious problems develop.

Warning Signs of an Insulin Reaction

An insulin reaction occurs when the blood sugar level falls too low (usually below 60 mg/dl). The medical term for a reaction is hypoglycemia. Insulin reactions are more likely when a person with diabetes:

  • Injects too much insulin
  • Skips a meal, eats too little, or waits too long between meals
  • Exercises or works more than usual

Hypoglycemia symptoms come on suddenly, and may progress from mild to severe.

Symptoms of Mild Hypoglycemia

When ONLY the following symptoms are present, give juice or sugar. Assistance is usually not needed.

  • Hunger
  • Cold sweat and a clammy feeling
  • Dizziness, weakness, or shakiness
  • Pounding heart or increase heart rate

Symptoms of More Serious Hypoglycemia

When the following symptoms are present, give juice or sugar. Assistance may be needed.

  • Nervousness or confusion
  • Headache
  • Blurred or double vision
  • Numbness or tingling in lips or fingers

Symptoms of Severe Hypoglycemia

When the following symptoms are present, assistance is ALWAYS required. Give glucose gel.

  • Paleness and slurred speech
  • Bizarre behavior

If convulsions occur, give glucagon.

Different people experience different symptoms. Ask your family member with diabetes to describe what happens and how he or she feels during an insulin reaction so that you will be able to recognize his or her unique symptoms.

Treating an Insulin Reaction


If the person is conscious and able to swallow, feed him or her some kind of FAST SUGAR FOOD:

  • Fruit juice (4 oz)
  • Candy (4-6 Life-Savers, 6 jelly beans, 2 "Chuckles"
  • Cola or other soda (not diet or sugar free)
  • Sugar, honey, or corn syrup (2 tbsp)

Never force fluids or foods if the person is unconscious or unable to swallow. Give glucagonif it is available and you've been instructed in technique. If glucagon is not available, rush the unconscious person to the hospital.

Glucagon Injection Kit (solution in syringe)

  1. Inject all solution into ampule
  2. Mix
  3. Draw into syringe
  4. Inject into upper arm, thigh, or buttocks


Usually the person responds in 5 to 10 minutes. Have him or her eat a snack:

  • Packaged peanut butter cracker sandwiches
  • Fruit or a cracker and milk
  • 1/2 cheese sandwich

Talk to the person about what might have caused the reaction, so that future reactions can be avoided. If the reaction was so severe that you had to administer glucagon, encourage the person to report it to his or her doctor.

Questions and Answers

Your diabetes educator and physician will help you set your own goals. For some people, a blood sugar level below 80 mg is too low, while for others a level under 100 mg is too low. A level over 120 before a meal is too high for some, while for others anything up to 150 mg is all right.

How serious is hypoglycemia?

  • You can easily treat hypoglycemia (insulin reaction) with fast-acting sugar. Even before you take sugar, your body begins to correct the sugar imbalance. The catecholamines (see above) released during a hypoglycemia episode cause the liver to release stored glycogen, which converts to glucose and raises your blood sugar. Prolonged, severe hypoglycemia (less than 20 mg for over l/2 hour) can result in damage to the brain or the heart.

What is a Somogyi effect?

  • When your liver releases a lot of stored glycogen in response to a reaction, high blood sugar results. This over-correction is called a rebound or Somogyi effect. High blood sugar with urine ketones and a feeling of exhaustion for a day following a reaction indicate a Somogyi effect.

How can I tell if I have slept through a night-time insulin reaction?

  • Symptoms include a headache when you awake, cold sweats, bad dreams, high blood sugar, and exhaustion.

REMEMBER: The care of diabetes is a team effort involving you, your physician, and the diabetes education staff where you receive your medical care. This handbook cannot - and was not meant to - replace this team effort. 

This handbook embodies the approach of the diabetes care team at the University of Massachusetts Medical Center. Different diabetes care teams may approach some aspects of diabetes care in ways that differ from those in this handbook. While most teams are in close agreement regarding the GENERAL PRINCIPLES of diabetes care, they may differ in the DETAILS. There can be more that one "right" way to approach a specific issue in diabetes management. 

Always remain in touch with your diabetes care team, and bring any questions you may have about the materials in this handbook to their attention! 

Copyright 1995-1999 Ruth E. Lundstrom, R.N. and Aldo A. Rossini, M.D. All rights reserved.
Feedback: send e-mail to Dr. Aldo Rossini