T4 (Levothyroxine)

How It Works

The tablets supply the main circulating reserve of thyroid hormone. Tissues convert part of this reserve into T3, which activates nuclear receptors controlling metabolic gene expression. This regulates heat production, oxygen consumption and the turnover of nutrients.

Thyroid Function and Metabolic Regulation

The hormone restores normal thyroid hormone availability when the thyroid produces too little. This corrects metabolic slowing caused by a deficiency. For someone concerned with physique and energy balance, the key distinction is between correcting low thyroid function and trying to increase an already normal metabolic rate.

• Providing a sustained reservoir for T3 production.
• Restoring thyroid hormone levels in deficiency.
• Regulating energy expenditure through tissue conversion to T3.

Post Cycle Therapy

The hormone does not require androgen directed PCT. Thyroid status is evaluated using the appropriate TSH and thyroid hormone results, while continuing treatment depends on the reason it was prescribed. An underlying thyroid deficiency remains relevant after the product is stopped.

Side Effects

Excess exposure can produce palpitations, atrial fibrillation, anxiety, sweating, insomnia, diarrhoea, muscle weakness and loss of lean tissue. Prolonged excess can reduce bone density. Ordinary thyroid hormone replacement is ineffective for weight loss in people with normal thyroid function, while excessive amounts carry potentially life threatening risks.