Liothyronine Interactions

Calcium salts (carbonate, citrate, acetate) can bind thyroid hormone in the gastrointestinal tract and reduce absorption of liothyronine (T3) much as they do with levothyroxine. This can blunt the effect of the dose and lead to suboptimal thyroid replacement.

Iron salts (ferrous sulfate, fumarate, gluconate, bisglycinate) can chelate thyroid hormone in the gut and reduce absorption of liothyronine, similar to the established interaction with levothyroxine. Concurrent dosing can cause inadequate T3 effect and elevated TSH.