What is the best time of day to administer Lantus (insulin glargine)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: October 14, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Best Time to Administer Lantus (Insulin Glargine)

Insulin glargine can be administered at any time of day, as long as it is given at the same time every day, with similar efficacy whether given in the morning, before dinner, or at bedtime. 1, 2, 3

Pharmacokinetic Profile of Insulin Glargine

  • Insulin glargine has a relatively constant concentration profile over 24 hours with no pronounced peak action time, making it an ideal basal insulin 1
  • It has an onset of action of approximately 1 hour after subcutaneous injection with a duration of action of approximately 24 hours 1
  • The peakless profile allows for more stable blood glucose levels between meals and overnight 1

Administration Timing Options

Morning Administration

  • Morning administration of insulin glargine has been shown to result in significantly fewer nocturnal hypoglycemic events (59.5%) compared to dinner (71.9%) or bedtime (77.5%) administration 3
  • Morning dosing provides similar glycemic control as bedtime dosing with equivalent HbA1c reductions 3, 4

Bedtime Administration

  • Traditionally recommended timing in many clinical settings 2
  • May provide better control of fasting blood glucose in some patients 5
  • FDA labeling indicates insulin glargine can be administered at any time of day but at the same time every day 2

Dinner Administration

  • Also provides effective glycemic control similar to morning or bedtime administration 3
  • Has intermediate rates of nocturnal hypoglycemia compared to morning (lowest) and bedtime (highest) administration 3

Clinical Considerations for Timing Decision

  • Consistency is more important than specific timing - the FDA label emphasizes administering insulin glargine at the same time every day 2
  • For patients experiencing nocturnal hypoglycemia with bedtime dosing, morning administration may be preferable 3
  • For patients with significant dawn phenomenon (early morning rise in blood glucose), bedtime administration may provide better control of fasting glucose 5
  • For older adults, the American Diabetes Association recommends changing timing from bedtime to morning when simplifying insulin regimens 6

Common Pitfalls to Avoid

  • Inconsistent timing of insulin glargine administration can lead to variable glycemic control and increased risk of hypoglycemia 2
  • Changing administration time should be done with increased blood glucose monitoring 2
  • Never mix insulin glargine with other insulins in the same syringe 2
  • Insulin glargine alone does not treat postprandial hyperglycemia and may need to be supplemented with short-acting insulin at mealtimes 7

In conclusion, while insulin glargine can be effectively administered at any time of day, morning administration may offer the advantage of reduced nocturnal hypoglycemia while maintaining equivalent glycemic control compared to evening or bedtime dosing 3, 4.

References

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.