Short answer: The Humulin R U-100 label gives each dose under the skin approximately 30 minutes before meals, usually alongside an intermediate or long-acting insulin. The dose is individualized by metabolic needs, glucose monitoring and goals, and the label gives no fixed starting dose. It may be given into a vein only under medical supervision. The label has no missed-dose rule.
This is what the FDA label says. Follow your prescriber. Your prescriber may use a different dose or pace than the label's standard schedule.
What Humulin R U-100 is approved for: Humulin R U-100 is a short-acting human insulin approved to improve blood sugar control in adults and children with diabetes (section 1).
Source
HUMULIN R (insulin human) injection, for subcutaneous or intravenous use, prescribing information and Patient Information. Eli Lilly and Company. DailyMed, version published September 7, 2026. DailyMed setid b519bd83-038c-4ec5-a231-a51ec5cc291f
Humulin R is injected under the skin of the thigh, upper arm, abdomen or buttocks approximately 30 minutes before meals, rotating sites within the same region. By injection it is generally used with an intermediate or long-acting insulin (sections 2.2 and 2.3).
It is U-100 (100 units/mL) in 10 mL and 3 mL multiple-dose vials, drawn up with a syringe. It can be given into a vein only under medical supervision, with close checks of blood sugar and potassium (sections 2.2 and 3).
The table below is the label's schedule, from the Dosage and Administration section. Numbers are copied exactly; the section is in brackets.
| Situation | What the label says |
|---|---|
| When to inject | Approximately 30 minutes before meals |
| Dose | Individualized by route, metabolic needs, glucose monitoring and glucose goal; no fixed starting dose is given |
| Changing from another insulin | The dose may need adjusting |
| Mixing | With Humulin N only; Humulin R drawn into the syringe first; inject immediately |
| Diluted (U-10 or U-50, under medical supervision) | With Sterile Diluent for Humulin R; 28 days at 41 F or 14 days at 86 F |
| IV infusion (under medical supervision) | 0.1 to 1 unit/mL in 0.9% sodium chloride; 48 hours refrigerated, then up to 48 more hours at room temperature |
| Presentation | Unopened, room temp up to 86 F | Unopened, refrigerated 36-46 F | In use, room temp up to 86 F | In use, refrigerated |
|---|---|---|---|---|
| 10 mL or 3 mL multiple-dose vial | 31 days | Until expiration date | 31 days | 31 days |
At room temperature, Humulin R can be used for 31 days in total, counting unopened and opened time.
Dose changes may be needed with changes in physical activity, meal content or timing, kidney or liver function, or during acute illness. Glucose is checked more often during any change to the insulin regimen.
The dose may need adjusting when Humulin R is used with certain other drugs.
Humulin R is protected from heat and light, never frozen, and not used after the expiration date or if it has been frozen.
Patients are taught how to handle illness, stress, an inadequate or skipped insulin dose, an accidental extra dose, too little food and skipped meals. The label does not spell out what to do in each case.
The Humulin R U-100 label gives no missed-dose rule. Section 17 says patients are instructed on handling an inadequate or skipped insulin dose, but neither the prescribing information nor the Patient Information says what to do.
The dose may need adjusting when changing from another insulin to Humulin R.
Any change of insulin strength, maker, type, site or method is made under close medical supervision with more frequent glucose checks. In type 2 diabetes, other diabetes medicines may need adjusting.
In Dose Track you set up Humulin R U-100 as a protocol with the dose and schedule your prescriber gave you. A protocol can hold dose steps, each with its own dose and length in days or weeks, so a step-up plan like the one on the label can be entered once and the app moves to the next step on its own. Reminders follow the schedule, and every dose is logged with the date and time, so you can see which step you are on and when your last dose was. The app follows what you enter; it does not choose or change a dose.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.