Tresiba Hair and Skin Changes: What the Clinical Evidence Actually Shows

What skin reactions does Tresiba cause?

The Tresiba label lists hypoglycemia, allergic reactions, injection site reactions, lipodystrophy, pruritus, rash, edema and weight gain as the reactions commonly associated with the drug [1]. The label's clinical trial data give rates for the skin-related ones: injection site reactions 3.8%, lipodystrophy 0.3%, and hypersensitivity or urticaria 0.9% [1].

Tresiba is insulin degludec, a once-daily basal insulin approved in 2015 and sold as a U-100 FlexTouch pen, a U-100 multiple-dose vial and a U-200 FlexTouch pen [1][2].

Lipodystrophy and localized cutaneous amyloidosis at injection sites

Two skin problems tied to injected insulin appear in the Tresiba label: lipodystrophy, reported in 0.3% of trial patients, and localized cutaneous amyloidosis at repeated injection sites [1].

The label's administration instructions name the thigh, upper arm and abdomen as injection sites. They say to rotate sites within the same region from one injection to the next to reduce the risk of both conditions, and not to inject into areas of lipodystrophy or localized cutaneous amyloidosis [1].

Can injecting into changed skin affect blood sugar?

Yes. The label says repeated insulin injections into areas of lipodystrophy or localized cutaneous amyloidosis have been reported to result in hyperglycemia, and a sudden change of injection site to an unaffected area has been reported to result in hypoglycemia [1]. It advises that people who have repeatedly injected into such areas change to unaffected areas and that blood glucose be monitored closely for hypoglycemia [1].

The label also states that the glucose-lowering time course of an insulin can vary with the area of injection and with the injection site's blood supply and temperature [1]. Degludec works from a depot: after injection it forms multi-hexamers in the subcutaneous tissue, and its long action comes mainly from slow absorption from that depot [1].

Does Tresiba cause hair loss?

Hair loss is not listed among the reactions commonly associated with Tresiba [1]. That does not establish that hair loss cannot occur with the drug; the label's adverse reaction data come from clinical trial experience rather than from hair-specific measurements [1].

The skin-related reactions the label does report are injection-site reactions in 3.8%, lipodystrophy in 0.3% and hypersensitivity or urticaria in 0.9%, with pruritus and rash also named among the common reactions [1].

Allergic and hypersensitivity skin reactions

Hypersensitivity or urticaria was reported in 0.9% of patients in the label's trial data [1]. The label warns that severe, life-threatening, generalized allergy including anaphylaxis can occur with insulins including Tresiba. It says that if a hypersensitivity reaction occurs, Tresiba should be discontinued, treated per standard of care, and the patient monitored until symptoms and signs resolve [1]. Tresiba is contraindicated in people with hypersensitivity to insulin degludec or to any of its excipients [1].

How Tresiba is injected

The Tresiba label says to inject it subcutaneously into the thigh, upper arm, or abdomen, to rotate sites within the same region, and to avoid areas of lipodystrophy or localized cutaneous amyloidosis [1]. It also says not to give Tresiba intravenously or by insulin pump, not to dilute or mix it with other insulins, and not to transfer it from the pen into a syringe [1]. The label notes that the pen's dose window shows the number of units to be delivered [1].