Definition
Liothyronine is a synthetic form of triiodothyronine (T3), a thyroid hormone. It's used to treat hypothyroidism (low thyroid hormone). It functions like natural T3, stimulating metabolism. Think of it as a supplement of the active thyroid hormone. Liothyronine offers direct T3, useful when the body doesn't convert T4 efficiently. Unlike insulin (blood sugar), liothyronine replaces thyroid hormone.