What is the ideal time to administer insulin in the morning?

From the Guidelines

The ideal time to administer morning insulin is typically 15-30 minutes before breakfast for rapid-acting insulins and 30-45 minutes before breakfast for regular insulin, as recommended by the most recent guidelines 1. When using rapid-acting insulin, it is essential to check blood glucose before injecting and adjust the dose according to the healthcare provider's instructions if the reading is outside the target range.

• Consistency is crucial, and insulin should be taken at the same time daily to maintain stable blood glucose levels.
• The timing recommendation exists because insulin needs time to enter the bloodstream and begin working before food causes blood glucose to rise.
• Rapid-acting insulins start working within 15 minutes, while regular insulin takes 30 minutes to become effective.
• For long-acting basal insulins, administration can be at a consistent time each morning, regardless of meals, as stated in the 2024 standards of care in diabetes 1.
• If exercise is planned in the morning, it may be necessary to adjust the insulin dose or timing to prevent hypoglycemia, and this should be discussed with a healthcare provider.
• The American Diabetes Association standards of medical care in diabetes also emphasize the importance of individualizing the timing of premeal insulin administration based on the type of insulin used, measured blood glucose level, timing of meals, and carbohydrate consumption 1.

From the FDA Drug Label

CLINICAL STUDIES The efficacy and safety of LEVEMIR given once-daily at bedtime or twice-daily (before breakfast and at bedtime, before breakfast and with the evening meal, or at 12-hour intervals) was compared to that of once-daily or twice-daily NPH human insulin or once-daily insulin glargine in non-blinded, randomized, parallel studies of 6004 patients with diabetes In one non-blinded clinical study (Study A, n=409), adult patients with type 1 diabetes were randomized to treatment with either LEVEMIR at 12-hour intervals, LEVEMIR morning and bedtime or NPH human insulin morning and bedtime. Overall glycemic control achieved with LEVEMIR was compared to that achieved with insulin glargine in a randomized, non-blinded, clinical study (Study B, n=320) in which patients with type 1 diabetes were treated for 26 weeks with either twice-daily (morning and bedtime) LEVEMIR or once-daily (bedtime) insulin glargine. The ideal time to administer insulin in the morning is before breakfast 2.

• This is based on the clinical studies that compared the efficacy and safety of LEVEMIR given twice-daily (before breakfast and at bedtime, before breakfast and with the evening meal, or at 12-hour intervals) to that of once-daily or twice-daily NPH human insulin or once-daily insulin glargine.
• The studies showed that administering insulin before breakfast resulted in similar glycemic control compared to other administration times.

From the Research

Ideal Time to Administer Insulin in the Morning

The ideal time to administer insulin in the morning can vary depending on the type of insulin and the individual's needs.

• According to a study published in 1983 3, administering insulin 60 minutes before meal ingestion provided plasma glucose and insulin profiles closest to normal and permitted less insulin to be used.
• Another study from 2006 4 compared the effects of administering insulin glargine at lunch-time, dinner-time, and bed-time in people with Type 1 diabetes, and found that bed-time injection led to hyperglycaemia in the early part of the night, which was improved by giving insulin glargine at lunch-time or dinner-time.
• A 2005 study 5 found that a regimen of biphasic insulin aspart twice daily, at breakfast and dinner, provided improved postprandial glucose control compared with other insulin regimens.
• However, other studies 6, 7 did not specifically address the ideal time to administer insulin in the morning, but rather compared the efficacy of different insulin analogues and regimens.

Key Findings

• Administering insulin 60 minutes before meal ingestion may provide optimal glucose control 3.
• The timing of insulin administration can affect glucose levels and hypoglycemia risk 4.
• Biphasic insulin aspart twice daily, at breakfast and dinner, may provide improved postprandial glucose control 5.
• Different insulin analogues and regimens may have varying effects on glucose control and hypoglycemia risk 6, 7.