Description

T3 (Liothyronine)

Active Thyroid Hormone Research Compound

T3, also known as triiodothyronine or liothyronine, is the biologically active form of thyroid hormone and plays a central role in the regulation of metabolism, energy expenditure, thermogenesis, growth, and cellular activity.

T3 is considerably more biologically active than T4 (thyroxine) and acts directly on thyroid hormone receptors throughout the body. Its central role in endocrine physiology has made T3 an extensively studied compound in metabolic and thyroid-related research.

How T3 Works

T3 produces its biological effects primarily by binding to nuclear thyroid hormone receptors (TRα and TRβ). These receptors regulate the transcription of genes involved in metabolism, energy production, growth, and cellular function.

The body naturally produces T3 both directly from the thyroid gland and through peripheral conversion of T4 into T3 by deiodinase enzymes.

T3 signaling influences numerous physiological processes, including:

• Basal metabolic rate
• Energy expenditure
• Thermogenesis
• Carbohydrate and lipid metabolism
• Protein metabolism
• Cardiovascular activity
• Mitochondrial function
• Growth and development

Key Characteristics

Biologically Active Thyroid Hormone
T3 is the primary active thyroid hormone responsible for many of the cellular effects associated with thyroid signaling.

High Receptor Activity
Compared with T4, T3 has substantially greater activity at thyroid hormone receptors.

Relatively Short Half-Life
Liothyronine has an approximate biological half-life of 1–2 days, substantially shorter than the approximately 6–7 day half-life commonly associated with T4.

Major Metabolic Regulator
T3 influences oxygen consumption, energy utilization and metabolic activity across numerous tissues.

Research Areas

T3 has been extensively investigated in research involving:

• Thyroid hormone signaling
• Basal metabolic rate
• Energy expenditure
• Thermogenesis
• Mitochondrial activity
• Lipid metabolism
• Glucose metabolism
• Thyroid receptor activation
• T4-to-T3 conversion
• Endocrine feedback mechanisms
• Hypothalamic-pituitary-thyroid axis
• Metabolic physiology

Compound Information

Compound: Liothyronine / Triiodothyronine (T3)
Hormone Class: Thyroid Hormone
Molecular Formula: C₁₅H₁₂I₃NO₄
Molecular Weight: 650.97 g/mol
Approximate Biological Half-Life: 1–2 days
Primary Targets: Thyroid Hormone Receptors TRα and TRβ

T3 vs. T4

T4 (thyroxine) functions largely as a circulating precursor hormone that can be converted into active T3 through deiodinase enzymes.

T3 acts more directly and has greater biological activity at thyroid hormone receptors, while T4 has a substantially longer half-life and serves as an important reservoir for thyroid hormone activity.

Studying the relationship between T3 and T4 is important for understanding thyroid hormone conversion, endocrine feedback, metabolic regulation, and thyroid physiology.

Notice & Acknowledgement