Liothyronine (T3) vs Tesamorelin
FDA Approved vs FDA Approved
monitor Mechanism-based · 50% Both Liothyronine (T3) and Tesamorelin promote fat breakdown. While additive fat loss is possible, excessive lipolysis can cause rapid free fatty acid elevation and cardiac strain. Monitor heart rate and adjust doses gradually.
Molecular Data
Liothyronine (T3) Tesamorelin
Weight 650.97 Da 5,135.9 Da
Half-life ~1 day 26-38 minutes
Chain — 44 amino acids
Type Thyroid hormone (C15H12I3NO4) GHRH analog
Key Benefits
Liothyronine (T3)
01 Direct and rapid increase in basal metabolic rate
02 Enhanced fat oxidation and lipolysis
03 Improved energy levels and reduction of hypothyroid fatigue
04 Faster-acting than T4 with effects noticeable within hours to days
05 Useful when peripheral T4-to-T3 conversion is impaired (illness, caloric deficit, stress)
06 Supports body temperature regulation and thermogenesis
07 Can improve cognitive clarity and reduce brain fog associated with low thyroid function
Tesamorelin
01 FDA-approved formulation
02 Selective visceral fat targeting (15-20% reduction)
03 Proven clinical efficacy
04 Standardized dosing
05 37% liver fat reduction in NAFLD
06 Preserved subcutaneous fat
Dosing Protocols
Liothyronine (T3)
25-75 mcg/day (replacement) / 1-2x daily (oral)
Tesamorelin
1.4-2mg daily (FDA-approved: 2mg for HIV lipodystrophy) / Once daily (evening preferred for GH rhythm)
HIV Lipodystrophy (FDA-approved) 1.4mg Once daily
Visceral Fat Reduction 2mg Once daily
Anti-aging/Body Composition 1-2mg 5-7x weekly
NAFLD Treatment 2mg Once daily (12 months)
Cognitive Enhancement 1mg Once daily (20 weeks)
Side Effects
Liothyronine (T3)
Tachycardia and palpitations (increased heart rate, especially at higher doses)
Anxiety, nervousness, and irritability
Insomnia and disrupted sleep architecture
Increased sweating and heat intolerance
Tremor (fine hand tremor, similar to hyperthyroid presentation)
Increased appetite despite accelerated metabolism
Loose stools or increased bowel frequency
Tesamorelin
Injection site reactions (17%)
Joint pain (13%)
Water retention
Contraindications
Untreated adrenal insufficiency (must correct cortisol deficiency before starting T3)
Acute myocardial infarction or unstable angina
Thyrotoxicosis or untreated hyperthyroidism
Known hypersensitivity to liothyronine or any tablet excipients
Uncorrected adrenal cortical insufficiency (risk of adrenal crisis)
Active malignancy
Pituitary disorders
Pregnancy
Research Evidence
Liothyronine (T3) Tesamorelin
Status FDA Approved FDA Approved
References 5 studies 5 studies
Latest September 2023 June 2025
FDA Approved Yes Yes
This comparison is for educational and research purposes only. Consult a healthcare professional before use.