The medication liothyronine is also known as tri-iodothyronine or T3. T3 is available commercially in Australia, as an immediate-release tablet (with lactose). Chemists are frequently requested to compound T3 in other capsule strengths, and often without lactose or in a slow release formulation and to add in T4, hydrocortisone or Vitamin D3. Prescriptions are required for this medication.