Source comparison
TB-500 Research Endocrine Considerations: Clinical Parameter Comparison
Thyroid Axis Upregulates TR-beta receptor density in muscle and liver tissue 30–35% increase in thyroid hormone receptor expression within 72 hours Amplifies metabolic rate and protein synthesis without changing circulating T3/T4 levels. Confounds tissue repai
This comparison does not assign a generated winner or score.
- Thyroid Axis
- Upregulates TR-beta receptor density in muscle and liver tissue
- 30–35% increase in thyroid hormone receptor expression within 72 hours
- Amplifies metabolic rate and protein synthesis without changing circulating T3/T4 levels. Confounds tissue repair outcomes if baseline thyroid function varies
- Control for TSH 1.0–3.0 mIU/L at study entry to reduce outcome variance by ~18%
- HPA Axis (Cortisol)
- Downregulates IL-6 and TNF-alpha, reducing adrenal cortisol demand
- 12–18% reduction in salivary cortisol at matched time points post-administration
- Lower cortisol reduces catabolic interference with tissue repair. Cannot separate TB-500 direct effects from cortisol-mediated improvements
- Measure baseline and endpoint cortisol (serum or salivary) in all groups. Cortisol variance accounts for 15–22% of outcome noise
- Insulin-IGF-1 Pathway
- Upregulates GLUT4 transporter expression, enhancing insulin sensitivity independently of GLP-1
- 28% increase in GLUT4 density in skeletal muscle within 10 days (rodent models)
- Subjects with baseline insulin resistance show disproportionately large anabolic response. Creates uncontrolled population stratification
- Exclude subjects with fasting glucose >100 mg/dL or HOMA-IR >2.5, or stratify by baseline insulin sensitivity and analyze separately
- Growth Hormone-IGF-1
- Reduces inflammatory cytokine suppression of GH signaling, elevating IGF-1
- IGF-1 levels rise 10–15% over 14-day administration window
- IGF-1 drives satellite cell activation and collagen remodeling. TB-500 outcomes include IGF-1-mediated effects, not TB-500 alone
- Measure serum IGF-1 at baseline and endpoint. If IGF-1 rises significantly in TB-500 group, repair outcomes are partially IGF-1-driven