Novolin 70/30 is a pre-mixed human insulin that combines 70 percent NPH (intermediate-acting) and 30 percent regular (short-acting) insulin in a single vial. It offers both mealtime and basal coverage in one injection, making it a convenient option for people who want fewer injections.
What Pre-Mixed Insulin Does
A pre-mixed insulin like Novolin 70/30 combines two different insulin types into one formulation. The regular insulin component starts working quickly to cover meals, while the NPH component provides longer-acting background coverage. This dual action means you can use one injection to address both needs, rather than giving separate basal and mealtime insulins.
The trade-off is less flexibility. With pre-mixed insulin, you cannot adjust the ratio of short-acting to intermediate-acting insulin. You must eat meals at consistent times and keep carbohydrate intake relatively steady to avoid blood sugar swings.
How Novolin 70/30 Works
After injection, the regular insulin component begins lowering blood sugar within 30 minutes, peaking in 2 to 12 hours because of the combined effect of both components. Total duration is up to 24 hours, though most of the action occurs within 10 to 16 hours.
Novolin 70/30 is injected subcutaneously, typically into the abdomen, thighs, upper arms, or buttocks. The abdomen usually offers the most consistent absorption.
Who Novolin 70/30 Is For
Novolin 70/30 is approved for adults and children with type 1 or type 2 diabetes who need insulin therapy. It is especially useful for people who prefer a simpler regimen with fewer injections and who eat meals at consistent times.
According to the American Diabetes Association, pre-mixed insulins are one option for people with type 2 diabetes who need to start insulin after oral medications are no longer sufficient to reach their A1C target. As with any insulin, Novolin 70/30 is not used for prediabetes, where lifestyle changes and oral medications are the standard approach.
Dosing and Administration
Novolin 70/30 is typically injected twice daily, 30 minutes before breakfast and 30 minutes before dinner. Some people take a third dose before lunch, though this is less common.
Starting doses depend on weight, A1C, and whether you are starting insulin for the first time or switching from another insulin. A common starting dose is 0.2 to 0.4 units per kilogram of body weight per day, divided between morning and evening injections.
| Action Profile | Time |
|---|---|
| Onset | 30 minutes |
| Peak | 2-12 hours (dual peak) |
| Duration | Up to 24 hours |
| Injection timing | 30 minutes before breakfast and dinner |
Preparing Novolin 70/30 for Injection
Because Novolin 70/30 contains NPH with protamine particles, it is a cloudy suspension rather than a clear solution. Before each dose, gently roll the vial or pen between your palms 10 to 20 times to evenly mix the suspension. Do not shake vigorously, as this can damage the insulin and create air bubbles.
After mixing, inspect the insulin. It should look uniformly cloudy with no clumps, particles, or discoloration. If it looks abnormal, discard the vial or pen and use a new one.
Common Side Effects
Like all insulins, Novolin 70/30 can cause side effects. The most common include:
- Hypoglycemia — The most significant risk, especially in the afternoon (from morning NPH peak) or overnight (from evening NPH peak).
- Weight gain — Commonly 2 to 4 kilograms when starting insulin.
- Injection site reactions — Redness, swelling, or itching that usually improves with site rotation.
- Lipohypertrophy — Fatty tissue buildup from repeated injections in the same spot.
- Allergic reactions — Rare, ranging from local hives to systemic reactions.
Hypoglycemia Timing With Novolin 70/30
The dual-peak action of Novolin 70/30 creates two windows where hypoglycemia is more likely. The morning dose’s regular component peaks 2 to 4 hours after breakfast, while the NPH component peaks 4 to 12 hours later, often in the afternoon. Similarly, the evening dose can cause overnight hypoglycemia.
Consistent meals and snacks help prevent these episodes. Blood sugar checks before meals, at bedtime, and occasionally in the middle of the night during adjustment periods help identify patterns that may need dose changes.
Who Should Avoid Novolin 70/30
Novolin 70/30 is not appropriate in every situation. It should not be used in:
- Treatment of diabetic ketoacidosis, which requires IV regular insulin
- Insulin pumps, because the cloudy suspension can clog tubing
- People with known hypersensitivity to any component
People with highly variable schedules, irregular meal timing, or who exercise unpredictably may find pre-mixed insulin difficult to dose safely and may do better with separate basal and bolus insulins.
Storage and Handling
Unopened Novolin 70/30 vials and pens should be refrigerated between 36 and 46 degrees Fahrenheit. Once in use, vials can be kept at room temperature (below 86 degrees Fahrenheit) for up to 42 days, and pens for up to 10 days. Check the package insert for specific guidance.
Never freeze insulin, and keep it out of direct sunlight and away from heat sources. Travel with insulin in an insulated bag with a cold pack, but avoid direct contact with ice.
Cost and Availability
Novolin 70/30 is available over the counter at most US pharmacies. Cash prices typically range from 25 to 50 dollars per vial, making it considerably more affordable than analog pre-mixed insulins like Humalog Mix 75/25 or NovoLog Mix 70/30, which can cost several hundred dollars per vial without insurance.
Recent insulin price caps under Medicare and state laws have lowered out-of-pocket costs further. Manufacturer savings programs are also available for eligible patients with commercial insurance.
The Bottom Line
Novolin 70/30 may help people with diabetes simplify their insulin regimen by combining short-acting and intermediate-acting insulin in one injection. It works best for people with consistent meal patterns and who value affordability and convenience over precise dose adjustments. If you are considering Novolin 70/30, talk with your healthcare team about whether the dual-peak profile matches your daily schedule and glucose patterns.
