DEAR EDITOR, We have read with interest the article published by Dora J, which recommends against prescribing liothyronine (L-T3) alone or in combination with levothyroxine (LT4) for hypothyroidism, because the short half-life of triiodothyronine (T3) means multiple daily doses are required, and there is no clear evidence in humans that combination therapy is superior to L-T4 alone (). No guidelines have recommended thyroid hormone replacement with L-T3 alone, but the question remains whether L-T3 + L-T4 combination therapy may be [...]