What insulin is equivalent to 70/30 (seventy/thirty)?

Direct Equivalents to 70/30 Insulin

The most direct equivalent to 70/30 insulin (70% NPH/30% Regular) is Humulin 70/30, which is the same human insulin formulation from a different manufacturer and represents the most cost-effective substitution option. 1, 2

Understanding 70/30 Insulin Composition

70/30 insulin is a premixed formulation containing:

• 70% NPH (intermediate-acting) insulin providing basal coverage 3
• 30% Regular (short-acting) insulin providing prandial coverage 3
• This combination addresses both fasting and postprandial glucose control with a single injection 4, 2

Available Equivalent Formulations

Human Insulin 70/30 Products (Direct Equivalents)

• Humulin 70/30: Identical composition to Novolin 70/30, most direct substitute 1, 2
• Novolin 70/30: The reference product mentioned in your question 3
• These are interchangeable on a unit-for-unit basis with the same 70% NPH/30% Regular composition 5

Rapid-Acting Insulin Analogue Premixes (Functional Equivalents)

• Insulin aspart 70/30 (NovoLog Mix 70/30): 70% protamine-crystallized insulin aspart + 30% soluble insulin aspart 4, 6
• Insulin lispro 75/25 (Humalog Mix 75/25): 75% insulin lispro protamine + 25% insulin lispro 4, 6
• Insulin lispro 50/50 (Humalog Mix 50/50): 50% insulin lispro protamine + 50% insulin lispro 4

Key Pharmacokinetic Differences

Human insulin 70/30 products have slower onset and longer duration compared to analogue premixes, with peak insulin levels reached in approximately twice the time 6. The analogue premixes achieve peak insulin levels twice as high and in half the time of human insulin 70/30 6.

Analogue premixes provide superior postprandial glucose control compared to human insulin 70/30, though long-term HbA1c control is comparable between formulations 6, 7. However, the American Diabetes Association notes that the pharmacodynamic profiles of premixed analogues may be suboptimal for covering postprandial glucose excursions 4.

Conversion Guidelines

When Switching Between Human Insulin 70/30 Products

• Maintain the same total daily dose initially when switching from Novolin 70/30 to Humulin 70/30 1
• Adjust distribution to 2/3 before breakfast and 1/3 before dinner (not equal doses) 1, 2
• Example: If taking 30 units AM and 20 units PM, convert to approximately 33 units AM and 17 units PM 1

When Switching to Analogue Premixes

• Transfer can often be made dose-for-dose from human insulin 70/30 to analogue premixes 5
• More frequent blood glucose monitoring is essential during transition, focusing on both fasting and postprandial levels 1, 8

Cost Considerations

Human insulin formulations (Humulin 70/30, Novolin 70/30) are typically less expensive than insulin analogue premixes and may be the appropriate choice for patients with cost concerns, relaxed A1C goals, or prominent insulin resistance 4, 2. These products can be purchased for considerably less than listed prices at select pharmacies 4.

Critical Clinical Caveats

Dosing Pitfalls to Avoid

• Never use the same dose for morning and evening injections—the morning dose should be higher (2/3 vs 1/3 distribution) 1, 2
• Do not convert on a 1:1 basis without adjusting the distribution of morning and evening doses 1, 8

Monitoring Requirements

• Increase blood glucose monitoring frequency during any transition period when hypoglycemia risk is highest 1, 2
• Monitor both fasting AND postprandial glucose levels, not just fasting 2
• Target fasting glucose 72-126 mg/dL (4.0-7.0 mmol/L) 2

Patient Education Essentials

• Consistent meal timing is particularly critical with premixed insulins to avoid hypoglycemia 1, 2
• Premixed insulins require more rigid meal schedules compared to basal-bolus regimens 2

Medication Incompatibility

• Never mix basal insulins like insulin glargine (Lantus) with premixed insulins in the same syringe due to pH incompatibility that alters pharmacokinetics 8