T-3 (Liothyronine Sodium)

What is T-3 (Liothyronine Sodium) and how does it work (Mechanism of Action)?

T-3 (Liothyronine Sodium) is a synthetic version of triiodothyronine, one of the two thyroid hormones. It is used to treat people with hypothyroidism (underactive thyroid). Thyroid hormones increase the metabolism (activity) of all body cells. Thyroid hormones play a vital role in supporting tissue growth and development in fetuses, infants, and children. In adults, thyroid hormones contribute to the maintenance of brain function, food intake, and body temperature. The FDA approved liothyronine in May 1956.

What is T-3 (Liothyronine Sodium) used for?

T-3 (Liothyronine Sodium), also known as Cytomel or Triostat, is prescribed to manage hypothyroidism and to treat or prevent different types of euthyroid goiters.

 T3 (Liothyronine Sodium) in Bodybuilding

T3 is a synthetic thyroid hormone that mimics triiodothyronine, the body’s natural thyroid hormone. In bodybuilding, it is not an anabolic steroid, but it is sometimes used for its powerful effects on metabolism and fat loss.

Bodybuilding Uses:

• Fat Burner: Boosts metabolism, helps burn calories, and reduces body fat.
• Cutting Cycles: Commonly used before competitions to achieve a lean, defined physique.
• Synergy with Steroids: Often combined with anabolic steroids to preserve muscle mass and lose fat (T3 alone can cause muscle breakdown).

What are the Side effects of T-3 (Liothyronine Sodium)?

Treatment with liothyronine is generally well-tolerated. If symptoms occur, they are usually due to toxic (excessive) thyroid hormone levels (hyperthyroidism).

Symptoms of hyperthyroidism include:

• Chest pain,
• Rapid heartbeat,
• Excessive sweating,
• Heat intolerance,
• Nervousness,
• Headaches,
• Tremors,
• Insomnia,
• Diarrhea,
• Vomiting,
• Weight loss,
• Fever, and rarely, cardiac arrest.

Women may also experience irregular menstrual cycles. Because thyroid hormones affect heart rate and metabolism, the impact of thyroid hormone treatment on the control of conditions such as atrial fibrillation, diabetes, and high cholesterol must always be considered.

What is the dosage of T-3 (Liothyronine Sodium)?

For hypothyroidism, the typical initial dose of liothyronine ranges from 5 to 25 mcg daily. The dose is then adjusted based on the patient’s response and blood thyroid hormone levels. The optimal dosage of liothyronine varies depending on age, weight, symptoms, blood thyroid hormone levels, and underlying conditions such as heart disease. Individuals diagnosed with hypothyroidism typically need thyroid hormone therapy for life.

Which Medications or supplements interact with T-3 25mcg?

Thyroid hormones affect how the body metabolizes medications.

• Hypothyroidism (low thyroid): Slows drug metabolism → drugs stay in the body longer.
• Hyperthyroidism (high thyroid): Speeds up metabolism → drugs are eliminated more quickly.

Main interactions:

• Theophylline (Theo-Dur): Slows elimination in hypothyroidism. With liothyronine treatment, clearance increases → may reduce its effectiveness. Blood levels should be monitored and doses adjusted.
• Cholestyramine (Questran): Reduces the absorption of liothyronine. Take thyroid hormones at least 4 to 5 hours apart.
• Warfarin (Coumadin): Liothyronine may increase the blood-thinning effect of warfarin, increasing the risk of bleeding. Dosage adjustment may be necessary.

 Is it safe to take T-3 (Liothyronine Sodium) during Pregnancy or Breastfeeding?

Thyroid hormones do not easily cross the placenta and are therefore safe for pregnant women.

Very small amounts of thyroid hormones can pass into breast milk. This does not pose a serious problem for breastfed infants.

Summary

T-3 (Liothyronine Sodium) (Cytomel, Triostat) is a medication used to treat hypothyroidism in adults and children. Before taking any medication, read the information on side effects, dosage, warnings and precautions, and safety during pregnancy.