GLOSSARY

Thyroid Hormone Pharmacology and Misuse
Thyroid hormone medicines replace deficient hormone or serve other defined clinical purposes.

Therapeutic effects and feedback. Endocrine medicines can replace deficient signals, activate or block receptors, or change hormone synthesis and metabolism. Physiological replacement differs from supraphysiological exposure. Dose, route, duration, comorbidities and feedback suppression influence both benefit and harm.

A distinction that matters. Excess exposure can cause thyrotoxicosis with arrhythmia, bone loss and muscle effects, making use for unindicated weight reduction or performance enhancement hazardous.

Clinical and sporting context. Legitimate treatment and anti-doping eligibility are separate questions. The current prohibited list, route-specific rules and applicable TUE process must be checked through official sources. Mechanistic descriptions should not be used to design unsupervised performance-enhancing drug protocols.