Hormone · AlphaStack™ Compound Database

T3 — Triiodothyronine

Also known as: Cytomel · Liothyronine · T3 · L-T3
WADA BannedHormone

The active form of thyroid hormone. Prescribed for hypothyroidism and thyroid cancer. Non-medical use carries the risk of permanent thyroid suppression and life-threatening cardiac effects.

Side Effects & Risks

Performance Use

T3 is used in performance settings to dramatically accelerate metabolic rate during cutting phases. The thyroid hormone controls the speed of virtually every metabolic process in the body and supraphysiological T3 produces fat loss that exceeds what is achievable through caloric restriction and training alone. Competitive bodybuilders use it in the...

Stacking & Combinations

T3 is most commonly combined with Clenbuterol in cutting protocols for additive metabolic acceleration. Because T3 at performance doses causes significant muscle catabolism, it is almost never used without anabolic support, meaning it typically appears in stacks that include Testosterone, Trenbolone, or other compounds specifically to offset the ti...

Real-World Risk

The risk of permanent thyroid suppression from exogenous T3 use is real and the probability increases with dose and duration. The thyroid axis does not always fully recover to baseline function after exogenous hormone use, particularly when the suppression has been prolonged or severe. Muscle catabo...

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