Liothyronine Sodium is the synthetic form of triiodothyronine (T3) the metabolically active thyroid hormone, distinct from Levothyroxine (T4) which requires conversion to T3 before exerting biological effect. This formulation delivers 25mcg per tablet in a 50 count blister pack, the same compound as CSD’s Cytomel branded T3 listing in our peptide range.

T3 bypasses the peripheral T4 to T3 conversion step entirely, delivering active hormone directly and producing a faster, more pronounced metabolic effect than T4 at an equivalent dose. This direct activity is precisely why T3 carries a different and generally higher risk profile than T4 when used outside of diagnosed need; its faster onset and shorter half-life of approximately 24 hours mean changes in metabolic rate happen more quickly and are felt more acutely than with T4.

Within a weight loss context, the same fundamental caution applies to T3 as to T4, but more acutely given its direct and faster acting mechanism. T3 is sometimes referenced in bodybuilding and weight loss contexts specifically because its faster, more pronounced thyroid hormone elevation produces a more immediately noticeable metabolic effect than T4. But this comes from artificially pushing thyroid hormone above the body’s natural regulated level, which the body actively works to counteract through pituitary feedback suppression. This commonly results in a rebound effect once T3 use stops, alongside the more immediate risks of using a fast acting thyroid hormone without medical supervision: significant muscle protein breakdown if thyroid hormone is elevated without adequate caloric and protein intake, cardiac strain including rapid heart rate and arrhythmia risk, and suppression of the body’s own thyroid function (the HPT axis) which can take time to recover after stopping.

Every batch of CSD’s Liothyronine is third party lab tested for concentration accuracy and purity before being made available, with COA documentation available on request. All orders ship discreetly across Canada in plain, unmarked packaging with no identifying information on the exterior.

Liothyronine is a fast acting thyroid hormone medication that should only be used to treat a diagnosed thyroid condition under medical supervision with regular blood testing. Unsupervised use for weight loss carries real risks including cardiac strain, muscle loss, and suppression of natural thyroid function, and is not a safe or sustainable approach to weight management.

Store in a cool, dry place away from direct light and heat.