Short answer: Both are NPH (isophane) human insulin, 100 units/mL, a cloudy intermediate-acting insulin for adults and children with diabetes, injected under the skin only.12 Novolin N comes in a vial and FlexPen; Humulin N in a vial and KwikPen. Neither label has trial results or side-effect rates, and neither compares them. Neither has a boxed warning.
| Novolin N | Humulin N | |
|---|---|---|
| Insulin | Insulin isophane human (NPH) 100 units/mL1 | Insulin isophane human (NPH) 100 units/mL2 |
| How often | Once or twice daily1 | Not fixed in the label; dose individualized2 |
| Forms | 10 mL vial; 3 mL FlexPen in 1-unit steps1 | 10 mL vial; 3 mL KwikPen in 1-unit steps2 |
| Action (label studies) | Starts about 1 to 2 hours; lasts up to 24 hours, depending on dose1 | Median most effect at 6.5 hours (2.8 to 13); peak level about 4 hours2 |
| Mixing in a syringe | With Novolin R, drawn first1 | With Humulin R or Humalog, drawn first2 |
| Mixing before use (pen) | FlexPen moved up and down 20 times; vial rolled 10 times1 | KwikPen rolled 10 times and inverted 10 times; vial rolled and inverted at least 10 times each2 |
| Into a vein or pump | No1 | No2 |
| Opened, room temperature | Vial 42 days up to 77 F; FlexPen 28 days up to 86 F; do not refrigerate1 | Vial 31 days; KwikPen 14 days, not refrigerated2 |
| Side-effect rates | None given; reactions listed without percentages1 | None given; reactions listed without percentages2 |
| Label type on DailyMed | Human OTC drug label1 | Human OTC drug label2 |
No. Neither label has a clinical studies section, and neither gives side-effect rates. Both list low blood sugar as the most common reaction, plus injection site and allergic reactions, swelling, skin pits or thickening, lumps under the skin and weight gain, without numbers.12 The Novolin N label gives no timing numbers beyond onset and duration; its pharmacokinetics section says only that they "have been established."1
The pen, the mixing partners and storage. Humulin N may be mixed in the syringe with Humulin R or Humalog; Novolin N with Novolin R. An opened Novolin N vial lasts 42 days at room temperature and the FlexPen 28 days; an opened Humulin N vial lasts 31 days and the KwikPen 14 days. Both are suspensions that must be mixed until evenly cloudy right before each dose.12
Which, if either, fits is for your prescriber. More detail: Novolin N side effects, Humulin N side effects, the Novolin N and Humulin N dosing schedules, how to store Humulin N and Humulin N vs Lantus: how does NPH insulin compare with glargine?.