Humulin is one of the most popular brands of insulin medication that includes:

  • Humulin R which is similar to naturally occurring insulin in the body.
  • Humulin N or insulin isophane (NPH) which is an intermediate-acting insulin.
  • Humulin 30/70 which is a mixture of both Humulin-R and Humulin-N.

There are two main types of insulin analogs. Background or basal insulin, delivers a long-term insulin coverage of up to 24 hours and a mealtime or bolus insulin which is fast-acting and taken prior to meals.

Humulin R is a mealtime, “regular” or neutral insulin that is short-acting. It can be taken to provide control glucose levels within 30 minutes of mealtime.

Humulin N is a background insulin that contains isophane which is a longer-lasting than rapid-acting insulin.

Humulin 30/70 consists of both (30% regular insulin and 70% insulin isophane).

What is it used for?

Humulin R is approved for the treatment for high glucose levels in addition with a healthy diet and exercise. It is used by both adults and children with diabetes mellitus.

All Humulin insulin analogs are very similar to the insulin produced naturally in the body.

What forms does Humulin regular insulin come in?

Humulin® R cartridge

Each mL contains 100 units of human biosynthetic insulin. Non-medical ingredients include m-cresol and glycerol. Medication may also contain hydrochloric acid, sodium hydroxide and dimethicone.

Humulin® R vial

Each mL contains 100 units of human biosynthetic insulin. Non-medical ingredients include glycerol and m-cresol; hydrochloric acid, sodium hydroxide and dimethicone.

Humulin® R KwikPen

Each mL contains 100 units of human biosynthetic insulin. Non-medical ingredients include glycerol and m-cresol; hydrochloric acid, sodium hydroxide and dimethicone.

Insulin is a hormone that is naturally produced in the human body by the pancreas. It helps manage blood glucose levels. For those with diabetes, the pancreas does not produce any or enough insulin to meet the body’s requirements. As a result, patients are at risk for severe complications unless they are put under a treatment program which can often result in taking insulin injections.

Diabetes is categorized by two main types. Type 1 diabetes which arises when the pancreas does not produce enough insulin and type 2, which is characterized by the cells of the body not responding adequately to insulin made in the body. Insulin is a hormone made int he body that promotes the absorption of sugar in the blood, liver, skeletal muscle and cells.

There are several types of insulin which differ in absorption rate and duration. Regular insulin is considered a short-acting insulin that normally takes within 30-60 minutes to start working after injection and has a duration of 2 to 4 hours after injection. It an last up to 6-8 hours.


The suggested dosage by doctors is contingent on a patients individual needs. Dosages are determined by how much natural insulin your body is producing and how well its able to use it. Your doctor may suggest making lifestyle changes that may include weight management, exercise and a balanced diet based on blood glucose testing.

Your dose of insulin must be injected under the skin (subcutaneously) as instructed by a doctor or nurse. Do not inject insulin directly into a vein and should not be used by an infusion insulin pump.

Dosages of insulin are measured in international units (IU). 1 ml of insulin contains 100 IU. Short acting-insulin are normally taken 30 minutes before meals. Long-acting insulin are usually taken alongside regular insulin which manages blood sugar levels in between doses.

Insulin should appear clear and colorless. Do not use if insulin appears cloudy, discolored, clumpy or contains floating particles.

Unopened bottles of insulin should be refrigerated until needed and used until the expiry date visible on the label. Do not freeze or expose to extreme heat or sunlight. Opened insulin can be kept at room temperature for no more than 28 days.

Usage should be followed according to your doctors instructions. Your insulin regimen (timing of injections with respect to meals) is crucial to keeping your blood glucose levels under control and to minimize any side effects.

Change injection sites to avoid the forming of fatty tissue underneath the skin. Speak to your doctor if you notice any skin thickening or pitting at the site of injection.

When taking insulin, it is important monitor glucose levels regularly or as recommended by your doctor or nurse. If blood glucose levels are showing as too high or low, you should contact your doctor.

Blood glucose levels may be affected and insulin requirements may require adjusting if experiencing any of the following:

  • illness
  • stress
  • surgery
  • injury
  • exercise
  • diet
  • travelling over time zones
  • certain medications

Keep insulin out of reach from children.

Insulin should not be disposed via wastewater (ie down the sink or toilet) or in the household trash. Speak with your pharmacist about proper methods to dispose of medication that is expired or no longer needed.

Do not stop taking this medication unless recommended by your doctor.

Side Effects

Like any medication, a side effect or unwanted symptom may occur. The severity can depend on each individual from temporary to permanent or mild to severe.

The listed side effects below are not experienced by everyone and should both risks and benefits should be explained by your doctor. If you are concerned about these side effects consult with your doctor.

The common side effects have been reported by only 1% of patients. Many can be managed or go away with time. Seek medical attention if these side effects are bothersome or appear severe so you can receive guidance on how to manage your symptoms. If they are not treated immediately can become more serious.

Symptoms include:

  • redness, swelling and itching at site of injection
  • anxiety
  • blurred vision
  • difficulty speaking
  • drowsiness
  • nausea
  • hunger
  • nervousness
  • increased heartbeat
  • confusion
  • headache
  • numbness or tingling in fingers, toes, lips and tongue
  • trembling
  • weakness, fatigue, cramps (signs of low potassium levels)
  • irregular heartbeat

Seek medical attention and stop taking medication if you are experiencing any of the following symptoms:

  • rash or blisters all over your body
  • seizures
  • difficulty breathing, wheezing
  • unconsciousness

Contact your doctor if you experience any side effects not listed above that you are concerned with.

Warnings & Precautions

Diabetics should wear diabetes identification such as a bracelet or necklace, carry a identification card indicating you are taking insulin.

Prior to starting treatment using this medication, you should let your doctor know if you have any existing medical conditions, whether you are pregnant or breastfeeding or other significant health problems you may have as it can affect how your doctor proceeds with treatment.

If you have severe allergic reactions that include swelling of the throat and face, difficulty breathing and a body rash, stop taking medication immediately and seek medical attention.

You should not take this medication if:

  • You are allergic to any of the ingredients
  • Have low blood glucose levels (hypoglycemia)

Your physician may recommend using Humulin for symptoms not listed below.

To not share insulin medication with others as it can lead to spreading infection and blood pathogens. Taking medication that is not prescribed for your individual needs can be harmful.

The effectiveness of your insulin dosage can depend on factors such as body weight, diet and other medications. Notify your doctor if you are taking another other medications, over the counter prescriptions, herbal medications, supplements and vitamins.

Also, let your doctor know if you are currently smoking, consuming caffeine, street drugs or drinking alcohol, let your doctor know as they can impact blood sugar levels.

Let your family friends know about signs and symptoms caused by diabetes such as hypoglycemia (low blood sugar levels). Keep a glucagon kit readily available and instruct them on how to use it in the event you lose consciousness.

High blood sugar (hyperglycemia) can occur if there is not enough insulin in your body or you forgot to take your dose. If not treated immediately this can lead to diabetic ketoacidosis or coma which can be fatal. Early symptoms of hyperglycemia can include nausea, vomiting, excessive thirst, loss of appetite, weight loss, drowsiness and an acetone or fruity odor from your breath. Contact your doctor immediately if you are experiencing these symptoms.

Low blood sugar (hypoglycemia) can occur if too much insulin is used, too much exercise or meals are missed. Early symptoms of hypoglycemia can include nervousness or shakiness, increased heartbeat, cold sweats, weakness, tingling or numbness of the lips, fingers or tongue. Hypoglycemia may be treated by eating sugary snacks or drinks. It’s important to carry a source of glucose with you at all time such as glucose tablets, candy, juice or regular soft drinks (not diet).

Signs of severe hypoglycemia may include:

  • loss of consciousness
  • seizures
  • disorientation

If patient is unconscious due to hypoglycemia, glucagon may be glucose injected through intravenous (into a vein).

It is essential to maintain glucose levels during pregnancy. Insulin requirements may decrease during the first trimester and increase during the second and third.

Breast feeding mothers may require an adjustment to their insulin treatment and diet.