What is Novolin R: Uses, Warnings & Interactions

Updated Apr 28, 2025  •  Published Dec 30, 2020

Novolin R is a short-acting human insulin that controls blood sugar spikes after meals. Doctors prescribe to adults and children with diabetes mellitus. Injections are made under the skin 30 minutes before a meal. People can use a syringe and needle or an injector pen to make these injections. Novolin R is an over-the-counter drug that can be purchased without a prescription.

Novolin R overview

BRAND NAMES:

  • Novolin R, Novolin R FlexPen

Generic Names:

  • Human insulin

Uses:

  • Treats diabetes

Therapeutic Classes:

  • Antidiabetic, insulin

Forms:

  • Injection

How it’s taken:

  • By injection

What is Novolin R used for?

Novolin R controls postprandial blood sugar spikes in adults and children with diabetes mellitus.

What form(s) does Novolin R come in

  • Vial

    • 10 mL of 100 units/mL human insulin

  • Injection pen

    • 3 mL of 100 units/mL human

What are common Novolin R doses?

  • For glycemic control in people with diabetes: Doses will vary; doses are injected 30 minutes before a meal

Common Novolin R prescriptions

  • Novolin R
    3ml of 100unit/ml pen

  • Novolin R
    10ml of 100unit/ml vial

How to take Novolin R

  • Follow all the instructions given by the prescriber.

  • Please read the Patient Information sheet and the Instructions for Use that come with this medicine.

  • Doses should be injected 30 minutes before a meal.

  • Only inject doses into the skin. 

    • Do not inject Novolin R into a blood vessel.

    • Do not use Novolin R in an insulin pump.

  • Inject doses into the skin on the buttocks, abdomen, thigh, or upper arm.

    • Rotate injection sites with each injection. 

    • Do not inject into skin that is damaged, bruised, thick, lumpy, scaly, hard, or scarred.

  • A healthcare provider will demonstrate how to administer injections. Ask for clarification if you’re uncertain about any part of the process. 

  • Start eating a meal 30 minutes after the injection.

  • How to prepare for an injection:

    • Wash your hands.

    • Always check the insulin type, concentration, expiration date, and appearance of the medicine. The medicine should appear clear and colorless. 

    • Use a new syringe and a new needle for each injection.

    • Use only syringes that are made for insulin injections. 

  • How to administer injections with a needle and syringe:

    • Do not use the medicine in the vial if the cap has been removed or if the insulin is cloudy, colored, or has particles in it.

    • Do not shake or roll the vial.

    • Withdraw a dose as outlined in the instructions.

    • The prescriber will instruct you about whether the skin needs to be pinched at the injection site. Follow these recommendations. If the doctor does not instruct you about pinching the skin, ask for clarification.

    • Wipe the skin with an alcohol swab and let dry.

    • Insert the needle into the skin.

    • Press the plunger.

    • Remove the needle when finished.

    • Do not recap the needle after giving an injection.

    • Dispose of the needle and syringe in a sharps container.

  • How to mix Novolin T with Novolin N:

    • Do not mix Novolin R with Novolin N unless instructed to do so by the prescriber.

    • Do not mix Novolin R with any other insulin other than Novolin N.

    • Review the Instructions for Use for preparing Novolin N for drawing up a dose. 

    • Draw enough air into the syringe to equal the dose of Novolin N.

    • Inject this air into the Novolin N vial.

    • Draw enough air into the syringe to equal the dose of Novolin R.

    • Inject this air into the Novolin R vial.

    • With the vial upside down, draw the Novolin R dose into the syringe. Do not draw in any of the air.

    • With the vial upside down, draw the Novolin N dose into the syringe. Do not draw in any of the air.

    • The total dose in the syringe should equal the total prescribed dose of the Novolin N and Novolin R doses.

    • Inject the mixture under the skin right away.

  • Storing Novolin R vials:

    • Store unopened vials in the refrigerator. Do not freeze.

    • Store used vials at room temperature for up to 42 days. Do not refrigerate.

    • Protect Novolin R from heat and direct light. 

    • Dispose of any Novolin R that has passed its expiration date.

    • Dispose of empty vials in a sharps container.

  • Using the Novolin R FlexPen:

    • Wash your hands with soap and water.

    • Remove the pen cap.

    • Attach the needle.

    • Always use a new needle for each injection. Only use a NovoFine, NovoFine Plus, or NovoTwist needle with the FlexPen.

    • Give an airshot with the pen. The directions are in the Instructions for Use.

    • Make sure the dose selector is set to “0.”

    • Turn the dose selector to the prescribed number of units. 

    • Wipe the skin with an alcohol swab and let dry.

    • The prescriber will instruct you to pinch or not pinch the skin where doses are injected. Follow those recommendations.

    • Insert the needle into the skin. Make sure the dose counter is visible.

    • Press and hold the dose button until the dose counter reaches “0.” 

    • Keep the needle in the skin for six seconds.

    • Pull the needle out of the skin.

    • Do not recap the needle.

    • Carefully remove the needle and dispose of it in a sharps container.

    • Never keep the needle attached to a pen when not in use. 

    • Replace the pen cap.

  • Storing the Novolin N FlexPen:

    • Store unused FlexPens in the refrigerator. Do not freeze.

    • Unused FlexPens can be stored at room temperature for up to 28 days.

    • Store a used FlexPen at room temperature for up to 28 days. Do not put used FlexPens back into the refrigerator.

    • Protect the medicine from heat and direct light. 

    • Dispose of any medicine that has passed its expiration date.

    • Novolin R FlexPens can be thrown away in the trash. Remove and dispose of the needle in a sharps container first.

What to do if you miss a dose of Novolin R

  • If a missed dose is remembered before the meal is eaten, take the missed dose and eat 30 minutes later.

  • Ask the prescriber what to do if you forget to take a Novolin R dose and then eat a meal.

    • Recommendations may vary. It’s likely the prescriber will suggest taking the dose within a certain time frame after the meal.

    • You must monitor your blood sugar levels. Take a reading as soon as you remember that you forgot the injection.

  • Do not take extra insulin to make up for a missed dose.

Novolin R contraindications

  • This medicine is not right for everyone. 

  • Do not use Novolin R if you have:

    • Low blood sugar (hypoglycemia)

    • Allergies to Novolin R

Novolin R warnings

  • People on insulin must have regular medical visits and blood tests to determine that dosing is correct and safe. Keep all appointments.

  • Tell all doctors and other healthcare providers that you take insulin. 

  • Tell the prescriber if you are pregnant, planning to become pregnant, breastfeeding, or have kidney disease or liver disease.

  • Certain changes in lifestyle or health may require insulin doses to change. Tell the prescriber about:

    • New or worsened stress

    • Injuries or surgery

    • Illness

    • Weight changes

    • Dietary changes

    • Increase or decrease in physical activity

  • Novolin R can cause serious side effects including:

    • Low blood sugar

    • Low potassium

    • Accidental injuries

  • Low blood sugar (hypoglycemia) is the most common side effect of insulin injections. 

    • Know the clinical signs of hypoglycemia and what procedures to follow if you experience signs of low blood sugar.

    • Always check the insulin labels before preparing an injection to make sure you’re using the correct insulin with the correct concentration.

  • Low potassium is another possible serious side effect. 

    • Familiarize yourself with the clinical signs of low potassium.

    • Contact a healthcare provider or get medical help if you experience any symptoms.

  • Insulin treatment increases the risk of accidental injuries. 

    • Do not drive or do anything else that could be dangerous until you know how this medicine affects you. 

    • Exercise caution around hazards in the house and at work.

  • Do not share insulin pens or needles with other people.

  • Do not inject Novolin R into thickened skin. 

Novolin R interactions

  • Make sure the prescriber knows about all the prescription drugs, over-the-counter medications, and supplements you use, even if they’re only used occasionally.

    • In particular, make sure the prescriber knows if you are taking antidiabetic drugs called thiazolidinediones, particularly if you have heart failure.

  • Many drugs raise or lower blood sugar levels or interact in other ways with Novolin R. The Novolin R dose may need to be adjusted when taking these drugs. These drugs include:

  • Always tell other healthcare providers that you are taking insulin shots before they prescribe new medications.

  • If a new drug or supplement is started or used, immediately inform your diabetes provider. Insulin doses may need to change.

  • Do not drink alcohol or use any medications containing alcohol.

Novolin R side effects

Serious side effects

Talk to the prescriber or healthcare team if you notice any signs or symptoms of a possible serious side effect including:

  • Low blood sugar: Dizziness, lightheadedness, sweating headache, confusion, shakiness, blurred vision, slurred speech, fast heartbeat, hunger, mood changes, anxiety, irritability

  • Low potassium: Muscle weakness, muscle twitching, palpitations, fatigue, tingling, numbness

  • Rapid weight gain, swelling in your hands, ankles, or feet, trouble breathing, tiredness

  • Allergic reaction: rash all over your body, trouble breathing, sweating

Less serious side effects

  • Redness, pain, itching, swelling, or skin changes where the shot is given

  • Weight gain

  • Fluid retention

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