Published January 2, 2026
Some people have accidentally mixed up two types of insulin pens: Kirsty (a fast-acting insulin, similar to Novolog) and Semglee (along-acting insulin, similar to Lantus). Both pens are made by Biocon Biologics. The pens look very similar (Figure 1). They both have a blue body and cap, and a light-colored label. Each pen has a colored band on its label and a matching-colored injection button (orange for Kirsty, purple or lavender for Semglee). Because the pens look so much alike, it is easy to grab the wrong one out of the box.
In one report, a pharmacist told us that their hospital usually uses Semglee but now it will also be getting Kirsty. They looked at the packaging and labels and worried that nurses and patients might mix up the two pens. If someone uses Kirsty (mealtime insulin) when they should use Semglee (bedtime insulin), it could cause low blood sugar, especially if Kirsty is given at bedtime by mistake. This can be dangerous, especially for people who have trouble seeing clearly. We have told the manufacturer about this problem and suggested that they make the pens easier to tell apart.
Here’s what you can do: To help tell the pens apart, you can use things like tape, rubber bands, or hair ties to wrap around one pen. You can also put labels on the pens or the boxes that say “long-acting” or “fast-acting.” Store the pens is separate, secure locations such as keeping Semglee (long-acting) in the bedroom, and Kirsty (fast-acting) in the kitchen or dining room, away from heat and moisture. Insulin does not need to be in the refrigerator after opening, but always keep the pens up and away, and out of reach of children and pets.
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