Skip to main content

Novolog Mix 70/30 PenFill Side Effects

Generic name: insulin aspart/insulin aspart protamine

Medically reviewed by Last updated on Sep 27, 2022.

Note: This document contains side effect information about insulin aspart/insulin aspart protamine. Some dosage forms listed on this page may not apply to the brand name Novolog Mix 70/30 PenFill.

Applies to insulin aspart/insulin aspart protamine: subcutaneous suspension.

Serious side effects

Along with its needed effects, insulin aspart/insulin aspart protamine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking insulin aspart/insulin aspart protamine:

More common

Incidence not known

  • Bloating or swelling of the face, arms, hands, lower legs, or feet
  • change in vision
  • chest tightness
  • cough
  • difficulty swallowing
  • hives, itching, skin rash
  • puffiness or swelling of the eyelids or around the eyes, face, lips or tongue
  • rapid weight gain
  • redistribution or accumulation of body fat
  • thickening of the skin at the injection site
  • unusual weight gain or loss

Get emergency help immediately if any of the following symptoms of overdose occur while taking insulin aspart/insulin aspart protamine:

Symptoms of overdose

  • Decreased amount of urine
  • dry mouth
  • increased thirst
  • irregular heartbeat
  • loss of appetite
  • mood changes
  • muscle pain or cramps

Other side effects

Some side effects of insulin aspart/insulin aspart protamine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Most common

  • Back pain
  • belching
  • bleeding, blistering, burning, coldness, discoloration of the skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site
  • body aches or pain
  • bone pain
  • diarrhea
  • dryness or soreness of the throat
  • ear congestion
  • general feeling of discomfort or illness
  • heartburn
  • hoarseness
  • indigestion
  • joint pain
  • loss of voice
  • runny or stuffy nose
  • shivering
  • sneezing
  • stomach discomfort, upset, or pain
  • stuffy nose
  • tender, swollen glands in the neck
  • trouble sleeping
  • voice changes
  • vomiting

For Healthcare Professionals

Applies to insulin aspart/insulin aspart protamine: subcutaneous suspension.


The most common adverse reactions observed with insulin therapy include hypoglycemia, allergic reactions, local injection site reactions, lipodystrophy, rash, and pruritus.[Ref]


Hypoglycemia is the most frequently reported adverse reaction with insulin therapy. It occurs if the dose of the insulin is too high in relation to the insulin requirement. In clinical trials, the frequency of hypoglycemia varied with patient population, dose regimens, and level of glycemic control. Weight gain has been attributed to the anabolic effects of insulin and the decrease in glycosuria.[Ref]

Very common (10% or more): Hypoglycemia (69%)

Frequency not reported: Weight gain[Ref]


Very rare (less than 0.01%): Anaphylactic reactions

Frequency not reported: Allergic reactions[Ref]


Injection site reactions including pain, redness, hives, inflammation, bruising, swelling, and itching, may occur. These reactions are usually transitory.[Ref]

Frequency not reported: Injection site reactions[Ref]


Frequency not reported: Transient, reversible ophthalmologic refraction disorder, worsening of diabetic retinopathy[Ref]

Rapid improvement or intensification of in glucose control has been associated with transitory, reversible ophthalmologic refraction disorder; however, long-term glycemic control decreases the risk of diabetic retinopathy.[Ref]


Frequency not reported: Peripheral edema[Ref]

Insulin may cause sodium retention and edema, especially if previously poor metabolic control is improved by intensified insulin therapy.[Ref]


Frequency not reported: Lipodystrophy, rash, pruritus[Ref]


Common (1% to 10%): Dyspepsia, diarrhea, abdominal pain[Ref]


Common (1% to 10%): Influenza-like symptoms

Frequency not reported: Anti-insulin antibodies[Ref]

In a 3-month, open-label study, anti-insulin antibodies and cross-reacting anti-insulin antibodies were monitored in patients using this insulin compared with an insulin mix of 70% NPH (human insulin isophane suspension) and 30% regular (human insulin injection). Changes in cross-reactive antibodies were more common after this mix but these changes did not correlate with a change in HbA1c or increase in insulin dose. The clinical significance of these antibodies has not been established. Antibodies did not increase further after long-term exposure (greater than 6 months).[Ref]


Common (1% to 10%): Back pain, skeletal pain[Ref]

Nervous system

Rapid improvement or intensification of in glucose control has been associated with acute and painful peripheral neuropathy; however, long-term glycemic control decreases the risk of neuropathy.[Ref]

Very common (10% or more): Headache (19%)

Common (1% to 10%): Neuropathy[Ref]


Postmarketing reports: Medication errors in which other insulins have been accidentally substituted[Ref]


Common (1% to 10%): Pharyngitis, rhinitis , upper respiratory tract infection[Ref]

More about Novolog Mix 70/30 PenFill (insulin aspart/insulin aspart protamine)

Other formulations

Related treatment guides


1. "Product Information. NovoLOG Mix 70/30 (insulin aspart-insulin aspart protamine)." Novo Nordisk Pharmaceuticals Inc (2022):

2. "Product Information. NovoLOG Mix 70/30 FlexPen (insulin aspart-insulin aspart protamine)." Novo Nordisk Pharmaceuticals Inc (2022):

3. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

4. Cerner Multum, Inc. "Australian Product Information." O 0

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.