Short answer: Both are mealtime insulins.12 Afrezza is human insulin powder inhaled at the start of each meal, for adults and children 6 and older; it has a boxed warning on bronchospasm and is not used with asthma or COPD. Humalog is insulin lispro injected within 15 minutes before or right after a meal, for adults and children. Afrezza's label compares it with insulin aspart, not Humalog.
| Afrezza | Humalog | |
|---|---|---|
| Insulin and route | Human insulin powder, inhaled by mouth from 4, 8 or 12 unit cartridges1 | Insulin lispro, injected under the skin, by pump or into a vein (U-100)2 |
| Approved for | Adults and children 6 years and older with diabetes1 | Adults and children with diabetes2 |
| When taken | At the beginning of each meal1 | Within 15 minutes before a meal or immediately after a meal2 |
| Speed (label studies) | First effect about 12 minutes; peak level 10 to 20 minutes after inhaling1 | Peak serum levels 30 to 90 minutes after a dose2 |
| Before starting | Medical history, exam and spirometry (FEV1); repeated after 6 months, then yearly1 | No lung testing in the label2 |
| Not used in | Asthma, COPD or other chronic lung disease; not recommended in people who smoke or recently quit1 | During low blood sugar, or with allergy to insulin lispro2 |
| Cough, type 1 adults | 29% vs 5% on injected insulin1 | Not reported as a common reaction2 |
| Missed dose | No instruction in the label1 | No instruction in the label2 |
| Boxed warning | Acute bronchospasm in chronic lung disease1 | None2 |
In a 24-week trial of 344 adults with type 1 diabetes, all on basal insulin, HbA1c fell 0.21% on Afrezza and 0.40% on injected insulin aspart. Afrezza met the 0.4% non-inferiority margin but lowered HbA1c less, and the difference was statistically significant. In a 26-week trial in children on basal insulin, Afrezza did not meet non-inferiority against a rapid-acting insulin (aspart, lispro or glulisine, chosen by the investigator).1 No Afrezza trial used Humalog as the named comparator. These numbers come from separate trials with different people, lengths and methods, so they are not a head-to-head comparison.
The Afrezza label converts each injected mealtime dose: up to 3 units becomes 4 units of Afrezza, 4 to 5 units becomes 8, 6 to 7 becomes 12, and 8 or more becomes 16. People new to insulin start at 4 units per meal. In type 1 diabetes Afrezza is always used with a basal insulin, and the label reports more diabetic ketoacidosis on Afrezza (0.43%) than on comparators (0.14%). Lung function fell a little more on Afrezza: a 40 mL greater drop in FEV1 over up to 2 years.1
Which, if either, fits is for your prescriber. More detail: Afrezza side effects, the Afrezza dosing schedule, the Humalog missed-dose page, how to store Humalog, Humalog vs NovoLog: what is different between the two mealtime insulins? and Lyumjev vs Humalog: what changes with the newer insulin lispro?.