Short answer: Both are regular human insulin, 100 units/mL, injected about 30 minutes before meals, for adults and children with diabetes.12 Novolin R comes in a vial and FlexPen; Humulin R U-100 in 10 mL and 3 mL vials. Neither label has trial results or side-effect rates, and neither label compares them. Neither has a boxed warning.
| Novolin R | Humulin R U-100 | |
|---|---|---|
| Insulin | Insulin human (regular) 100 units/mL1 | Insulin human (regular) 100 units/mL2 |
| When injected | Approximately 30 minutes before the start of a meal1 | Approximately 30 minutes before meals2 |
| Forms | 10 mL vial; 3 mL FlexPen in 1-unit steps1 | 10 mL and 3 mL vials2 |
| Action under the skin | Starts about 30 minutes; most effect 1.5 to 3.5 hours; ends about 8 hours1 | Starts about 30 minutes (10 to 75); most effect about 3 hours; ends about 8 hours (3 to 14)2 |
| Mixing in a syringe | With Novolin N, Novolin R drawn first1 | With Humulin N only, Humulin R drawn first2 |
| Insulin pump | Not recommended, because of the risk of precipitation1 | Not addressed in the label2 |
| Into a vein | Only under medical supervision1 | Only under medical supervision2 |
| Opened, room temperature | Vial 42 days up to 77 F; FlexPen 28 days up to 86 F; do not refrigerate1 | Vial 31 days up to 86 F, refrigerated or not2 |
| 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 the same kinds of reactions without numbers: low blood sugar, which is the most common, injection site reactions, rare severe allergy, low potassium, skin pits or thickening, lumps under the skin, swelling and weight gain.12 Both say the dose may need adjusting when switching from another insulin, under close medical supervision.
The pen, the mixing partner and storage. Novolin R has a FlexPen; Humulin R U-100 comes only in vials. Each label names its own brand of NPH for mixing: Novolin N for Novolin R and Humulin N for Humulin R. An opened Novolin R vial lasts 42 days at room temperature and is not refrigerated, while an opened Humulin R vial lasts 31 days. The Novolin R label says it is not recommended in insulin pumps; the Humulin R label does not mention pumps.12
Which, if either, fits is for your prescriber. More detail: Novolin R side effects, Humulin R side effects, the Novolin R and Humulin R dosing schedules and Humulin N vs Lantus: how does NPH insulin compare with glargine?.