T4 & T3 Cytomel

Cytomel is the brand for liothyronine sodium, which is T3 - the active form of thyroid hormone. Sodium levothyroxine is T4, which the body converts to T3. Both are prescription thyroid medications, and both are the foundation of genuine fat loss when a person is actually hypothyroid, because a properly diagnosed and treated underactive thyroid is one of the few real, treatable causes of stubborn weight gain.

Why this category needs care

Thyroid hormone has a narrow therapeutic window and no meaningful margin for error. Too much causes tachycardia, tremor, heat intolerance and, in the worst cases, atrial fibrillation or bone loss. Thyroid function has to be tested before anyone takes it and re-tested while taking it, and the dose adjusted against those numbers. The mistake people make is treating it like a stimulant rather than a hormone replacement.

Verification

• Label names the compound - liothyronine sodium for T3, levothyroxine sodium for T4 - with the mcg strength.
• Mcg and mg get confused constantly; read the units carefully.
• Sealed bottle, printed batch and expiry, tablets intact.
• Store cool and dry, away from heat and moisture.

Quick answers

T4 or T3?

T4 is prohormone (converts to T3 at your own rate); T3 is the active hormone, faster and stronger. T3 wins on control; T4 wins on gentle. Dosing and conversion math sit in the Cytomel guide.

Will my thyroid shut down?

Exogenous T3 suppresses TSH/T4 - which is why taper-down finishing (not cold stop) is standard, and why bloodwork at weeks four and eight matters. The stack with clenbuterol is laid out in the clen + T3 stack guide, including the taurine and heart-rate pieces.

How fast do thyroid cuts show?

Metabolic output moves within the first week - appetite and temperature often first. It amplifies a deficit; it does not replace one, and protein must stay high or the scale will eat muscle instead of fat.