Short answer: Both are insulin glargine 100 units/mL, injected once a day at the same time.12 Basaglar covers type 1 diabetes in adults and children and type 2 in adults, in pens only. Semglee covers adults and children with diabetes, in a vial and a pen, and its label calls it biosimilar to Lantus. Neither label reports a trial against the other.
| Basaglar | Semglee | |
|---|---|---|
| What is in it | Insulin glargine 100 units/mL1 | Insulin glargine-yfgn 100 units/mL2 |
| Approved for | Type 1 diabetes in adults and children; type 2 diabetes in adults1 | Adults and children with diabetes2 |
| Forms | 3 mL KwikPen or Tempo Pen, up to 80 units per injection1 | 10 mL vial; 3 mL prefilled pen2 |
| What the label says it is | No biosimilar statement1 | Biosimilar to Lantus (insulin glargine)2 |
| Own trials on the label | Against comparator insulin glargine products, 100 units/mL1 | None; tables are insulin glargine studies against NPH insulin2 |
| Severe lows, type 1 adults | 4% at 52 weeks (Basaglar trial)1 | 6.5% to 10.6% across insulin glargine Studies A to C2 |
| Switching from glargine 300 units/mL | 80% of that dose1 | 80% of that dose2 |
| Missed dose | No instruction in the label1 | No instruction in the label2 |
| Boxed warning | None1 | None2 |
Basaglar's own trials compared it with "another insulin glargine product, 100 units/mL, or a non-U.S.-licensed insulin glargine." HbA1c fell 0.35% vs 0.46% in type 1 adults over 24 weeks, and 1.3% in both groups in type 2.1 The Semglee label instead prints insulin glargine studies against NPH insulin and rests on biosimilarity to Lantus.2 These numbers come from separate trials with different people, lengths and methods, so they are not a head-to-head comparison.
No. Both list low blood sugar as the most common reaction, with the note that the long action may delay recovery, plus never sharing pens, mix-ups, low potassium, allergic reactions and heart failure with thiazolidinediones. Neither is used in a pump, into a vein, or for diabetic ketoacidosis.12
Which, if either, fits is for your prescriber. More detail: Basaglar side effects, Semglee side effects, the Basaglar and Semglee dosing schedules, the Basaglar and Semglee missed-dose pages, how to store Basaglar, how to store Semglee, Basaglar vs Lantus: how do the two insulin glargine brands differ? and Semglee vs Lantus: what does biosimilar mean on the label?.