What is the Difference Between NPH and Regular Insulin?

The main difference between NPH insulin and regular insulin lies in their duration of action and absorption time.

NPH (Neutral Protamine Hagedorn) insulin is a longer-acting insulin used to cover blood sugar between meals and to satisfy the overnight insulin requirement. It has an onset of 1 to 2 hours, a peak effect of 4 to 6 hours, and a duration of action of more than 12 hours. NPH insulin is a suspension of different sized crystals and needs to be remixed thoroughly before each injection.

Regular insulin, on the other hand, is a shorter-acting insulin that works more quickly and has a shorter duration of action. It is often used in combination with NPH insulin in pre-mixed formulations.

Key differences between NPH and regular insulin include:

  • Duration of action: NPH insulin has a longer duration of action (more than 12 hours) compared to regular insulin.
  • Onset and peak: NPH insulin has an onset of 1 to 2 hours and a peak effect of 4 to 6 hours, while regular insulin has a more rapid onset and peak effect.
  • Insulin combination: NPH insulin is often combined with regular insulin in pre-mixed formulations to provide a combination of short and intermediate-acting insulins.

Self-assessment quizzes can be found on the Diabetes Education Online website for more information on NPH and regular insulin.

Comparative Table: NPH vs Regular Insulin

Here is a table comparing the differences between NPH and Regular Insulin:

Characteristic NPH Insulin (Intermediate-acting) Regular Insulin (Short-acting)
Onset of Action (hr) 1-2 ~1
Duration of Action (hr) 14+ 5-8
Peak Effect 6-14 -
Insulin Type Combination of human and cow/pig insulin Human insulin
Appearance Cloudy Clear
Injection Route Subcutaneous Subcutaneous

NPH insulin is an intermediate-acting insulin with an onset of action of approximately 2 hours, a peak effect between 6 and 14 hours, and a duration of action of 10-16 hours. It is a combination of human insulin and cow or pig insulin. Regular insulin is a short-acting insulin with an onset of action of about 1 hour and a duration of action of 5-8 hours. It is a human insulin.