Humulin 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 formulation. It is typically injected twice a day, before breakfast and before dinner, to provide both background and mealtime coverage.
What Is in the Bottle
Humulin 70/30, manufactured by Eli Lilly, contains 100 units of human insulin per milliliter. Of every 100 units, 70 are NPH isophane suspension and 30 are regular soluble insulin. The NPH portion provides slower, intermediate-acting coverage; the regular portion handles more immediate post-meal glucose rises.
The product is available as a 10 mL vial for use with syringes or as a KwikPen 3 mL disposable pen. Both require refrigeration until first use and can typically be stored at room temperature for up to 31 days after opening, according to the FDA prescribing information.
Onset, Peak, and Duration
Because Humulin 70/30 contains two components, its action curve has two phases.
| Parameter | Time Range |
|---|---|
| Onset | 30 to 60 minutes |
| First peak (regular) | 2 to 4 hours |
| Second peak (NPH) | 4 to 12 hours |
| Total duration | Up to 24 hours |
This dual profile is why the drug is suitable for twice-daily dosing. The regular component covers the immediate meal, while the NPH carries glucose control through the hours between doses.
Typical Dosing Schedule
Dosing is individualized, but a common starting pattern is roughly two-thirds of the total daily dose before breakfast and one-third before dinner, per the FDA label. Adjustment follows fasting and pre-dinner glucose patterns over several days. The goal is to reach targets set by your clinician, often in line with A1C levels guidelines from the American Diabetes Association.
Humulin 70/30 should be injected about 30 minutes before the meal, not immediately before, because the regular insulin needs time to begin working. Taking it at the start of the meal may lead to post-meal spikes and later hypoglycemia.
How to Inject Humulin 70/30
- Roll the vial or pen gently between your palms 10 times. Do not shake.
- Inspect: the suspension should appear uniformly cloudy. Do not use if it has clumps or crystals.
- Attach a new needle if using a pen. With a vial, draw the prescribed dose into a U-100 insulin syringe.
- Choose an injection site: abdomen (fastest absorption), thigh, upper arm, or buttocks.
- Pinch up skin, insert the needle at 90 degrees, and inject slowly.
- Count to 10 before removing the needle to avoid leakage.
- Rotate sites within an area to minimize lipohypertrophy.
Who Typically Uses Pre-Mixed Insulin?
Pre-mixed regimens can simplify care for people who struggle with multiple daily injections or have difficulty mixing two insulins themselves. Common candidates include:
- Older adults with type 2 diabetes needing structured dosing
- People with consistent meal schedules
- Patients transitioning from oral medications to insulin
Pre-mixed insulin is generally not preferred when meals are irregular, when intensive glycemic control is needed, or in type 1 diabetes, where basal-bolus therapy offers better flexibility. See our treatment hub for an overview of regimens.
Hypoglycemia and Other Risks
The most common and serious side effect of Humulin 70/30 is low blood sugar. Recognize early symptoms:
- Shakiness, sweating, fast heartbeat
- Hunger, headache, irritability
- Difficulty concentrating, blurred vision
- In severe cases: confusion, seizures, loss of consciousness
Always carry a fast-acting carbohydrate source such as glucose tabs or juice. Never skip meals after dosing. Alcohol can blunt hypoglycemia awareness and increase risk for several hours after drinking.
Other possible adverse effects include weight gain, injection site reactions, hypokalemia, and, rarely, severe allergic reactions. Report any persistent redness, swelling, or hives to your clinician.
Drug Interactions to Discuss
Several classes of medications can raise or lower insulin requirements. Tell your prescriber about:
- Oral diabetes medications, GLP-1 receptor agonists
- Beta-blockers (may mask hypoglycemia symptoms)
- Corticosteroids (often raise insulin needs)
- Thiazide diuretics, atypical antipsychotics
- Thyroid hormones
Storage and Stability
Unopened Humulin 70/30 is stored at 36 to 46 degrees Fahrenheit. Do not freeze; discard if frozen. Once in use, a vial is stable at room temperature up to 86 degrees Fahrenheit for 31 days, and a KwikPen for 10 days. Do not expose to direct sunlight or heat. Always check the expiration date before each injection.
Cost, Biosimilars, and Access
Humulin 70/30 has been available in the United States since the 1980s and is one of the lower-cost branded insulins. Lilly and other manufacturers offer patient assistance, savings cards, and a capped $35 monthly copay for most commercially insured patients. Check Lilly’s patient access page and your pharmacy benefits for current pricing.
The Bottom Line
Humulin 70/30 is a long-standing pre-mixed human insulin that delivers both basal and mealtime coverage in one injection, given twice daily about 30 minutes before breakfast and dinner. It can simplify dosing for people with stable meal patterns, but it is less flexible than basal-bolus therapy. Only adjust dosing with guidance from your prescribing clinician.
