What the FDA labels say about taking them together
Insulin degludec and lithium
Insulin degludec's FDA label of July 1, 2022 names lithium in its drug interactions section; the lithium labels PlainMeds reads (4) do not name insulin degludec. The insulin degludec label: “Drugs That May Increase or Decrease the Blood Glucose Lowering Effect of Insulin Degludec Drugs: Alcohol, beta-blockers, clonidine, and lithium salts.”
Check it at the source: the insulin degludec FDA label on DailyMed (effective July 1, 2022, Novo Nordisk Pharma, Inc.); the lithium FDA label on DailyMed (effective December 23, 2025, Glenmark Pharmaceuticals Inc., USA).
What does the insulin degludec label say about lithium?
Insulin degludec label, drug interactionsDrugs That May Increase or Decrease the Blood Glucose Lowering Effect of Insulin Degludec Drugs: Alcohol, beta-blockers, clonidine, and lithium salts.
Source: FDA drug label (Insulin Degludec), Novo Nordisk Pharma, Inc., effective July 1, 2022 (SPL set c1be283d-4b1d-4996-b2a7-4488dbff3037), via openFDA; the full label on DailyMed
What does the lithium label say about insulin degludec?
Lithium's label (effective December 23, 2025) and its 3 other brand-application labels do not name insulin degludec 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 degludec | Lithium | |
|---|---|---|
| Labeled for | Type 2 diabetes, Type 1 diabetes | Bipolar disorder |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $11.39 per mL 100 unit/mL pen | $0.104 per capsule 300 mg capsule |
| Shortage now | No current entry | 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