Short answer: Both are mealtime insulins for adults and children with diabetes.12 Humulin R is regular human insulin, injected about 30 minutes before meals. Humalog is insulin lispro, injected within 15 minutes before a meal or right after, and acts faster and for a shorter time. The Humalog label's trials used Humulin R as the comparator and found similar HbA1c control. Neither has a boxed warning.
| Humulin R U-100 | Humalog | |
|---|---|---|
| Insulin | Regular human insulin 100 units/mL1 | Insulin lispro, 100 or 200 units/mL2 |
| When injected | Approximately 30 minutes before meals1 | Within fifteen minutes before a meal or immediately after a meal2 |
| Peak level (healthy volunteers) | Mean peak 36 to 150 minutes after a dose1 | 30 to 90 minutes, vs 50 to 120 for regular human insulin in the same studies2 |
| Type 1, 12 months, ages 12+ | HbA1c +0.1%; severe lows 21%2 | HbA1c −0.1%; severe lows 17%2 |
| Children 9 to 19, 8 months, with Humulin N | HbA1c +0.1%; severe lows 1.1%2 | HbA1c +0.1%; severe lows 1.1%2 |
| Forms | 10 mL and 3 mL vials1 | Vials, KwikPen, Junior KwikPen, Tempo Pen, cartridge; U-200 KwikPen2 |
| Mixing in a syringe | With Humulin N only1 | U-100 with NPH insulin only2 |
| Side-effect rates | None given; reactions listed without percentages1 | Table vs regular human insulin, e.g. headache 29.6% vs 22.1% in type 12 |
| Label type on DailyMed | Human OTC drug label1 | "Rx only" on the cartons2 |
In a 12-month trial of people aged 12 and older with type 1 diabetes, Humalog was injected right before meals and Humulin R 30 to 45 minutes before. HbA1c changed −0.1% on Humalog (81 people) and +0.1% on Humulin R (86 people), and severe lows affected 17% and 21%. The label says glycemic control, insulin doses and severe lows were similar, with no diabetic ketoacidosis in either group.2
In an 8-month crossover study of 463 children aged 9 to 19, both with Humulin N, HbA1c rose 0.1% in each group, severe lows affected 1.1% in each, and ketoacidosis 2.4% vs 1.9%. In children aged 3 to 11, Humalog before or right after meals and Humulin R 30 minutes before meals gave similar control.2
The Humalog label says one unit of Humalog has the same glucose-lowering effect as one unit of regular human insulin, with a faster start and shorter action. Both labels say a dose change may be needed when switching from another insulin, under close medical supervision.21 The Humulin R label has no side-effect rates; the Humalog label's rates are compared with regular human insulin and are close to it.
Which, if either, fits is for your prescriber. More detail: Humulin R side effects, Humalog side effects, the Humulin R and Humalog dosing schedules, the Humalog missed-dose page, how to store Humalog and Humalog vs NovoLog: what is different between the two mealtime insulins?.