Insulin aspart and Levothyroxine interaction
Insulin aspart and Levothyroxine: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Insulin aspart label · effective 2026-01-14
…Insulin Aspart Drugs: Atypical antipsychotics (e.g., olanzapine and clozapine), corticosteroids, danazol, diuretics, estrogens, glucagon, isoniazid, niacin, oral contraceptives, phenothiazines, progestogens (e.g., in oral contraceptives), protease inhibitors, somatropin, sympathomimetic agents (e.g., albuterol, epinephrine, terbutaline), and thyroid hormones.
…may decrease the blood glucose lowering effect: atypical antipsychotics, corticosteroids, danazol, diuretics, estrogens, glucagon, isoniazid, niacin, oral contraceptives, phenothiazines, progestogens (e.g., in oral contraceptives), protease inhibitors, somatropin, sympathomimetic agents (e.g., albuterol, epinephrine, terbutaline), and thyroid hormones ( 7 ).
From the Levothyroxine (Levothyroxine Sodium) label · effective 2024-07-10
Worsening of Diabetic Control : May worsen glycemic control and result in increased antidiabetic agent or insulin requirements.
Worsening of Diabetic Control Addition of levothyroxine therapy in patients with diabetes mellitus may worsen glycemic control and result in increased antidiabetic agent or insulin requirements.
Antidiabetic Therapy Addition of levothyroxine to antidiabetic or insulin therapy may result in increased antidiabetic agent or insulin requirements.
Acute Adrenal Crisis in Patients with Concomitant Adrenal Insufficiency Chronic autoimmune thyroiditis, which can lead to myxedema coma, may occur in association with other autoimmune disorders such as adrenal insufficiency, pernicious anemia, and insulin‑dependent diabetes mellitus.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.