🧠 Thyrotropin Releasing Hormone (TRH): The Master Metabolic Messenger 🔍 Introduction: What Is TRH and Where It Comes From Thyrotropin Releasing Hormone (TRH) is a tiny tripeptide (pyroglutamyl-histidyl-proline amide) synthesized in the paraventricular nucleus of the hypothalamus. It serves as the key “top-level” hormone in the hypothalamic‑pituitary‑thyroid (HPT) axis, triggering the release of thyroid stimulating