Trade Names: T3, T4, Tertroxin, Eltroxin

Chemical Names: Liothyronine Sodium & Thyroxine Sodium

Routes: Oral

Liothyronine Sodium (T3) and Levothyroxine (T4)

Liothyronine Sodium (T3)

Chemical Nature: The L-form of triiodothyronine (T3), the active thyroid hormone.
Uses: Primarily used for treating hypothyroidism and severe conditions such as myxedema coma.
Mechanism: Has a direct effect on metabolism, boosting energy production and fat breakdown.

Levothyroxine (T4)
Nature: A prohormone that converts into T3 in the body.
Uses: The most common thyroid hormone replacement therapy used for hypothyroidism.

Key Differences and Features
Potency: Both T3 (Liothyronine) and T4 (Levothyroxine) are potent thyroid hormones capable of alleviating symptoms and enhancing metabolism.
Conversion: T4 is converted into T3 within the body, making T4 a precursor to the active hormone.
 
Safety and Usage Considerations
Proper Use: Requires regulated dosing, proper cycles, and medical supervision to avoid health risks.

Side Effects:  
Headache  
Mood disturbance  
Nervousness  
Sweating  
Irregular heartbeat  
Increased bowel movements  
Menstrual irregularities

Overdose Risks:  
Can cause heart rates to exceed 150 beats per minute.
Tertroxin (T3):  
Mostly eliminated within one day.
Symptoms typically resolve quickly.

Eltroxin (T4):  
Symptoms may last weeks.
Overdose can lead to heart failure or permanent heart damage.