Insulin human regular (Injection)


Insulin Human Regular (IN-su-lin HUE-man REG-yoo-lar)

Treats diabetes mellitus.

Brand Name(s)

Humulin R, Humulin R Concentrated U-500, Novolin R, ReliOn Humulin R, Relion Novolin R

When This Medicine Should Not Be Used

How to Use This Medicine


  • Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
  • A healthcare provider should also teach you how to give insulin shots. Make sure you understand how to use the medicine and give yourself the shots.
  • IV: A nurse or other trained health professional may give you this medicine into a vein if you are in the hospital.
  • When you get a new supply of insulin, check the label to be sure it is the correct type of insulin. Do not change the brand of your insulin unless your doctor tells you to.
  • Humulin® R Concentrated U-500: Be very careful when you measure the dose. This form has more medicine in the same amount of solution than the U-100 form of insulin. You will need to use less of the solution for each dose. You should eat a meal within 30 minutes of injecting this insulin.
  • You will be shown the body areas where this shot can be given. Use a different body area each time you give yourself a shot. Keep track of where you give each shot to make sure you rotate body areas.
  • Use only syringes that are specially made for insulin. It is best to always use the same brand and type of syringe. Ask your pharmacist if you are not sure which kind of syringe you should use.
  • Use a new needle and syringe each time you inject your medicine.
  • If you are using a reusable syringe, you must sterilize it before each dose. Follow the sterilizing directions that come with your syringes.
  • The insulin should look clear and colorless. Do not use if it is cloudy or thickened.

If a dose is missed:

  • Call your doctor or pharmacist for instructions.

How to Store and Dispose of This Medicine

  • Store the opened vial of insulin in the refrigerator. Do not freeze. If you cannot keep your insulin in the refrigerator, you may store it at room temperature for up to 31 days. Keep the vial as cool as possible and away from heat and light.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any leftover medicine, containers, and other supplies. Throw away old medicine after the expiration date has passed.
  • Throw away used needles in a hard, closed container that the needles cannot poke through. Keep this container away from children and pets.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Some medicines can change the amount of insulin you need to use and make it harder for you to control your diabetes. Make sure your doctor knows about all other medicines you are using.
  • Make sure your doctor knows if you are also using an oral medicine for blood sugar control (a thiazolidinedione medicine, such as pioglitazone, rosiglitazone, Actos®, Actoplus Met®, Avandia®).
  • Make sure your doctor knows if you are using aspirin, clonidine (Catapres®), danazol (Danocrine®), disopyramide (Norpace®), fluoxetine (Prozac®), guanethidine (Ismelin®), isoniazid (Nydrazid®), lithium (Eskalith®, Lithobid®), niacin (vitamin B3), octreotide (Sandostatin®), pentamidine (NebuPent®), reserpine, a phenothiazine medicine (such as promethazine, Phenergan®, Thorazine®), pramlintide (Symlin®), salbutamol (Ventolin®), somatropin (Nutropin®), terbutaline (Bricanyl®), thyroid medicine, or birth control pills. Tell your doctor if you are also using a sulfa drug (Bactrim® or Septra®), a steroid (such as dexamethasone, hydrocortisone, methylprednisolone, prednisolone, prednisone, Medrol®), an MAO inhibitor (Eldepryl®, Marplan®, Nardil®, Parnate®), blood pressure medicine (such as atenolol, benazepril, enalapril, lisinopril, metoprolol, propranolol, Bystolic®, Lotrel®, Tenormin®, Vasotec®, Zestoretic®, Zestril®), or medicine to lower cholesterol (such as gemfibrozil, fenofibrate, Lopid®, Tricor®).
  • Make sure your doctor knows if you are also using medicine that might lower the potassium levels in your blood, such as a diuretic (water pill).
  • Do not drink excessive amounts of alcohol.

Warnings While Using This Medicine

  • Make sure your doctor knows if you are pregnant or breastfeeding. Tell your doctor if you have kidney disease, liver disease, heart failure, or hypokalemia (low potassium in the blood).
  • You may have to use this insulin in combination with another type of insulin or with oral diabetes medicine to keep your blood sugar under control.
  • You might sometimes have low blood sugar while you are using insulin. This is more likely if you miss a meal, exercise for a long time, or drink alcohol.
  • You might sometimes have high blood sugar if you miss a dose, do not take enough insulin, overeat or do not follow your meal plan, or do not exercise as much as usual.
  • The use of insulin together with oral diabetes medicines called TZDs (thiazolidinediones) can cause your body to retain too much water. This could make congestive heart failure worse, or it could lead to heart failure. Call your doctor if you have trouble breathing, rapid weight gain, or swelling in your hands, ankles, or feet.
  • Never share insulin pens or cartridges with other people under any circumstances. It is not safe. Sharing needles or pens can transmit hepatitis, HIV, and other blood-borne illnesses.
  • Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Dizziness, lightheadedness
  • Dry mouth, increased thirst, muscle cramps, nausea or vomiting, uneven heartbeat
  • Fast or pounding heartbeat, sweating
  • Hunger, trembling
  • Increased thirst
  • Mood changes
  • Rapid weight gain, swelling in your hands, ankles, or feet
  • Trouble breathing, cold sweat, bluish-colored skin
  • Urinating more or more often than normal

If you notice these less serious side effects, talk with your doctor:

  • Blurred vision or trouble seeing
  • Numbness, tingling, or burning pain in your hands, arms, legs, or feet
  • Redness, itching, swelling, or any changes in your skin where the shot is given

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Version Info

  • Last reviewed on 8/4/2014

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