When does Lantus (insulin glargine) peak?

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: November 7, 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.

Lantus (Insulin Glargine) Peak Time

Lantus (insulin glargine) has no peak action time—it provides a relatively constant, peakless insulin concentration over 24 hours. 1, 2, 3

Pharmacokinetic Profile

  • Onset of action: Approximately 1 hour after subcutaneous injection 1, 2
  • Peak: None—no pronounced peak in plasma insulin levels 1, 2, 3
  • Duration: Approximately 24 hours 1, 2, 3

Clinical Significance of the Peakless Profile

The absence of a peak is the defining characteristic that distinguishes Lantus from intermediate-acting insulins like NPH. 1, 2

  • The peakless profile results from insulin glargine's unique formulation: it is soluble at acidic pH (4.0) but precipitates in the neutral pH of subcutaneous tissue, creating microprecipitates that slowly release insulin 4, 5, 6

  • This provides a relatively constant concentration/time profile over 24 hours, mimicking physiologic basal insulin secretion more closely than NPH insulin 3, 5

  • The lack of peak significantly reduces the risk of hypoglycemia, particularly nocturnal hypoglycemia, compared to NPH insulin. 1, 2, 4, 5, 6

Comparison with Other Insulins

The following table demonstrates how Lantus differs from other insulin types 1, 2:

Insulin Type Onset Peak (hours) Duration (hours)
Rapid-acting (aspart, lispro) 5 minutes 1-2 3-4
Regular insulin 15 minutes 3-4 6-8
NPH (intermediate-acting) 1 hour 6-8 12
Lantus (glargine) 1 hour None 24

Important Clinical Caveats

  • The time course of action may vary between individual patients and even within the same patient over time. 3

  • Lantus provides basal insulin coverage only and does not address postprandial glucose excursions—it must be combined with rapid-acting or short-acting insulin at mealtimes for complete glycemic control 1, 7

  • The peakless profile allows for once-daily administration at any time of day (bedtime, morning, or other convenient time), though consistency in timing is recommended 1, 7, 6

References

Related Questions

When does Lantus (insulin glargine) peak?
Is Insulin Glargine (IG) YFGN the same strength as Lantus (Insulin Glargine)?
What type of insulin is Basaglar (glargine)?
For an adult with type 2 diabetes inadequately controlled (HbA1c ≥ 9 % or ≥ 8 % with hyperglycaemia symptoms, fasting glucose > 180 mg/dL), what are the differences, indications, advantages and disadvantages of initiating basal insulin glargine versus premixed insulin 70/30?
For a patient on basal insulin like glargine (insulin glargine) given at night and NPO (nil per os) till surgery, should blood glucose levels be checked every 4 hours overnight and is D5 (5% dextrose) necessary?
What's the next step for a patient with elevated Hemoglobin A1c (HbA1c) levels, currently taking metformin (biguanide) 1000mg twice a day and insulin glargine (long-acting insulin) 30 units at bedtime?
What is the best course of treatment for a 40-year-old female with relapsed anorexia nervosa, significant weight loss, orthostatic hypotension, and a history of Adderall (amphetamine and dextroamphetamine) abuse?
Are my patient's medications at risk for adverse interactions?
What is the typical dosage and treatment goal of Fludrocortisone (mineralocorticoid) for patients with primary adrenal insufficiency, such as Addison's disease?
How to downtitrate Fraction of Inspired Oxygen (FiO2) in a patient with a partial pressure of oxygen (PO2) of 300?
What are the implications of a low normal ejection fraction and small distal right coronary artery on cardiac health?

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.