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Thyroid Support
4.3 Rating
Oral tablet (1-3 times daily)

Liothyronine (T3)

Synthetic T3 thyroid hormone used alone or in combination with T4 for patients who do not fully convert T4 to T3.

Overview

Liothyronine is synthetic triiodothyronine (T3), the most active thyroid hormone. Some patients with hypothyroidism do not adequately convert T4 to T3 and may benefit from combination therapy or T3 supplementation. It has a faster onset and shorter duration of action compared to T4.

How It Works

Liothyronine provides T3 directly to the body, bypassing the need for T4-to-T3 conversion. T3 enters cells and binds to thyroid hormone receptors in the nucleus, directly activating gene transcription that controls metabolic rate, energy production, and cellular function.

Benefits

Direct T3 supplementation
Rapid onset of action
May improve symptoms unresolved by T4 alone
Beneficial for poor converters
Can enhance mood and energy
Useful in combination protocols

Potential Side Effects

Heart palpitations
Anxiety
Insomnia
Tremor
Sweating
Requires multiple daily doses

Dosage Information

Typical dose is 5-25mcg daily, often split into 2-3 doses due to its short half-life of about 24 hours. When used in combination with T4, the T4 dose is usually reduced.

Quick Facts

Administration

Oral tablet (1-3 times daily)

Rating

4.3 / 5.0

Category

Thyroid Support

Common Symptoms

Persistent fatigue on T4 alone
Poor T4-to-T3 conversion
Residual hypothyroid symptoms
Brain fog

Common Questions

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