Consult your doctor if following side effects appear with Cytomel. Allergic reactions like hives, difficulty in breathing, swelling of the face, lips, tongue, and throat, Temporary hair loss, especially in children, Headache, Mental/mood changes, Increased sweating, Sensitivity to heat, Diarrhea, Menstrual changes, Chest pain, Fast, pounding, or irregular heartbeat, Swelling of ankles, feet, or face, Severe dizziness, Trouble breathing Fact Table Formula C15H11I3NNaO4 License US FDA Bioavailability 95% Legal status US: RX Only Chemical Name Liothyronine Elimination half-life 2.5 days Dosage (Strength) 5mcg (100 tablets), 25mcg (100 tablets) Pregnancy Consult a doctor Brands Cytomel Protein binding 99.7% PubChem CID 16218759 MedlinePlus a682462 ChEBI 6484 ATC code H03AA02 DrugBank DB00279 KEGG D07522 Routes of administration Oral