What the FDA labels say about taking them together
Insulin glargine and lithium
Insulin glargine's FDA label of June 16, 2026 names lithium in its drug interactions section; the lithium labels PlainMeds reads (4) do not name insulin glargine. The insulin glargine label: “Drugs that May Increase or Decrease the Blood Glucose Lowering Effect of LANTUS Drugs: Alcohol, beta-blockers, clonidine, and lithium salts.”
Check it at the source: the insulin glargine FDA label on DailyMed (effective June 16, 2026, Eli Lilly and Company); the lithium FDA label on DailyMed (effective December 23, 2025, Glenmark Pharmaceuticals Inc., USA).
What does the insulin glargine label say about lithium?
Insulin glargine label, drug interactionsDrugs That May Increase or Decrease the Blood Glucose Lowering Effect of BASAGLAR Drugs: Alcohol, beta-blockers, clonidine, and lithium salts.
Source: FDA drug label (Insulin Glargine, BLA761201), Biocon Biologics Inc., effective January 23, 2026 (SPL set 3ac85ebb-5594-59c8-77fd-df254329d151), via openFDA
Source: FDA drug label (Lantus Solostar, BLA021081), sanofi-aventis U.S. LLC, effective June 2, 2025 (SPL set d5e07a0c-7e14-4756-9152-9fea485d654a), via openFDA
Source: FDA drug label (Toujeo, BLA206538), Sanofi-Aventis U.S. LLC, effective May 30, 2025 (SPL set c9561d96-124d-48ca-982f-0aa1575bff36), via openFDA
Source: FDA drug label (BASAGLAR KwikPen), Eli Lilly and Company, effective June 16, 2026 (SPL set 0ad21db3-2b1c-4ed9-a687-bdd6a74d0aae), via openFDA; the full label on DailyMed
What does the lithium label say about insulin glargine?
Lithium's label (effective December 23, 2025) and its 3 other brand-application labels do not name insulin glargine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Lithium Carbonate), Glenmark Pharmaceuticals Inc., USA, effective December 23, 2025 (SPL set 63b3790f-a9b5-47f4-bae1-ddf8b43c13c1), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Insulin glargine | Lithium | |
|---|---|---|
| Labeled for | Type 2 diabetes, Type 1 diabetes | Bipolar disorder |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $2.90 per mL 100 pen | $0.104 per capsule 300 mg capsule |
| Shortage now | A presentation being discontinued | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once