70/30 insulin is a premixed insulin product that combines 70 percent intermediate-acting insulin with 30 percent short- or rapid-acting insulin in a single vial or pen. The premix simplifies diabetes care to two daily injections — usually before breakfast and dinner — and is most often used in type 2 diabetes (T2D) when a simpler regimen is preferred over basal-bolus therapy.
How 70/30 Insulin Works
The 70 percent component provides background (basal-like) coverage that lasts roughly 14-24 hours. The 30 percent component provides mealtime (prandial) coverage during the next 4-8 hours. Injected before breakfast, the premix covers breakfast peak (short component) and lunch peak (NPH peak). Injected before dinner, it covers dinner peak and overnight basal needs.
This dual-action profile means meals must be eaten on a relatively predictable schedule. Skipping or delaying meals after a 70/30 dose raises hypoglycemia risk; eating much more carbohydrate than usual leads to high postprandial glucose because the dose is fixed at injection time.
Available 70/30 Brands
| Brand | Components | Type | Mealtime Window |
|---|---|---|---|
| Humulin 70/30 | 70% NPH + 30% Regular | Human insulin | 30 min before meal |
| Novolin 70/30 | 70% NPH + 30% Regular | Human insulin | 30 min before meal |
| ReliOn 70/30 (Walmart) | 70% NPH + 30% Regular | Human insulin | 30 min before meal |
| NovoLog Mix 70/30 | 70% Aspart Protamine + 30% Aspart | Analog insulin | Within 15 min of meal |
| Humalog Mix 75/25 | 75% Lispro Protamine + 25% Lispro | Analog (close cousin) | Within 15 min of meal |
Who Benefits Most From 70/30
Premixed insulin is well-suited to people with type 2 diabetes who:
- Eat meals at consistent times and in consistent amounts.
- Need fewer daily injections for adherence reasons.
- Have stable basal insulin needs that don’t fluctuate by activity or shift work.
- Cannot easily learn or pay for a multi-injection basal-bolus regimen.
- Have moderate insulin resistance not yet requiring U-500 concentration.
It is generally not recommended for people with type 1 diabetes (T1D), pregnant women, anyone using an insulin pump, or those with highly variable meal schedules.
Dosing Patterns
A common starting regimen for an insulin-naive person with T2D is roughly 0.4-0.5 units per kilogram of body weight per day, split as two-thirds before breakfast and one-third before dinner. Adjustments are usually made every 3-7 days based on fasting and pre-dinner glucose readings. Always follow your prescriber’s specific dosing instructions; the figures above are general examples, not personal medical advice.
Cost Considerations
Human insulin 70/30 (Humulin, Novolin, ReliOn) is among the most affordable insulin options in the United States. ReliOn 70/30 at Walmart sells for roughly $25 per vial cash price as of 2025-2026, making it a critical safety net for uninsured or underinsured patients. Analog mixes like NovoLog Mix 70/30 cost significantly more but offer faster onset and meal-time flexibility.
The 2023 federal price cap of $35 per month for insulin under Medicare Part D, and similar private-payer initiatives by Lilly and Novo Nordisk, have reduced out-of-pocket cost for many people. Always check current pricing with your pharmacy and insurer.
Side Effects and Risks
- Hypoglycemia — particularly mid-morning (NPH peak) and overnight (NPH carryover); always carry fast-acting glucose.
- Weight gain — common with insulin therapy generally.
- Injection site reactions — rotate sites within an area to prevent lipohypertrophy.
- Hypokalemia — relevant in hospital or high-dose situations.
- Allergic reactions — rare with modern formulations.
Storage and Handling
Unopened 70/30 vials and pens belong in the refrigerator at 36-46 degrees F. Once opened, they last about 28 days at room temperature for analog mixes and 10-14 days for human insulin mixes — always check the specific package insert. Roll the vial or pen gently between your palms before each dose to remix the cloudy suspension; do not shake vigorously, which can cause foaming.
70/30 in the Bigger Picture
If you are still in the prediabetes range, premixed insulin is not part of standard treatment. Lifestyle modification, weight management, and sometimes metformin or GLP-1 medications come first. Learn more about prediabetes care in our treatment hub and how progression is tracked through A1C testing. Premixed insulin enters the picture when oral therapies and basal-only regimens no longer maintain target A1C in T2D.
The Bottom Line
70/30 insulin is a practical, often inexpensive premixed option that simplifies diabetes care to two daily injections. The trade-off is rigid meal timing and a flatter peak structure than basal-bolus therapy. Whether 70/30, an analog mix like NovoLog Mix, or a basal-bolus regimen is right for you depends on your A1C, hypoglycemia history, lifestyle, and budget — a discussion to have honestly with your diabetes care team.
