Insulin glargine

also known as: Lantus, Basaglar, Toujeo, Semglee, Rezvoglar

The dominant once-daily basal insulin for two decades (Lantus, Sanofi, 2000) — the pI-shift design causes microprecipitation in subcutaneous tissue for a nearly peakless 24-hour absorption profile; Toujeo (U-300) is the same molecule at 3× concentration.

A once-daily basal insulin analog (Lantus, Sanofi, FDA-approved 2000) engineered to shift the isoelectric point to physiologic pH, causing the drug — soluble at pH 4 in the vial — to microprecipitate after SC injection at pH 7.4, producing slow, nearly peakless 24-hour absorption; available as Lantus (U-100), Toujeo (U-300), and biosimilars Basaglar, Semglee, and Rezvoglar.

Mechanism of action

Insulin receptor agonism with a unique absorption profile driven by pI engineering. The addition of two C-terminal arginines to the B-chain shifts the isoelectric point from ~5.4 to ~6.7; the drug is formulated as a soluble acidic (pH 4) solution but precipitates into microcrystals on contact with subcutaneous tissue at pH 7.4, then slowly redissolves to deliver monomers over ~24 hours.

Primary uses

Type 1 diabetes mellitus (basal)
Type 2 diabetes mellitus (basal)

Typical dosing

once daily (same time each day) (subcutaneous)

Fully individualized. Typical T2DM starting dose 10 units or 0.1–0.2 units/kg, titrated to target fasting glucose.

Regulatory status

FDA-approved 2000 as Lantus (Sanofi). Toujeo (U-300 formulation) approved 2015. Basaglar (Lilly biosimilar) approved 2015. Semglee (Mylan) approved 2020 and granted interchangeable designation in 2021.

References

[fda-pi] FDA. Lantus (insulin glargine) prescribing information. Sanofi, updated 2024.
[fda-pi] FDA. Toujeo (insulin glargine U-300) prescribing information. Sanofi, 2015.
[pubmed] Rosenstock J, et al. "Basal insulin therapy in type 2 diabetes: 28-week comparison of insulin glargine (HOE 901) and NPH insulin." Diabetes Care, 2001;24:631-636.

Related peptides

NPH insulin (isophane)

The classical intermediate-acting insulin — regular human insulin co-crystallized with protamine to produce ~12-hour action; still widely used for cost reasons despite being largely superseded by analog basal insulins for T1DM.

Insulin detemir

Novo Nordisk's fatty-acid-acylated basal insulin (Levemir, 2005) — the myristoyl chain enables reversible albumin binding, extending the half-life; Novo Nordisk announced global discontinuation in December 2023 (US supply ended 2024).

Insulin degludec

Novo Nordisk's ultra-long-acting insulin (Tresiba, 2015) — forms soluble multi-hexamers in SC tissue that slowly dissociate for a >42-hour half-life and a flat, forgiving dosing window; the basal insulin with the lowest hypoglycemia risk profile.

Insulin icodec

Novo Nordisk's once-weekly basal insulin (Awiqli, EMA 2024) — the first weekly insulin to reach market; FDA refused to approve in July 2024 (CRL citing type 1 diabetes hypoglycemia data), leaving it approved in the EU, UK, Canada, Switzerland, and Japan while pending US resubmission.

Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.