Sermorelin vs TB-500 (Thymosin Beta-4)

Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.

SermorelinTB-500 (Thymosin Beta-4)
CategoryPeptidesPeptides
Standard DoseResearch indicates 200-300 mcg administered once daily at bedtime via subcutaneous injection.Research indicates 2-2.5 mg administered twice weekly via subcutaneous injection.
TimingBedtime administration (aligns with natural nocturnal GH release). On empty stomach.No strict timing requirements. Can be administered at any time of day. Systemic action means injection location is not critical.
Cycle Duration12-24 week cycles. Some protocols use continuous treatment.Loading phase: 4-6 weeks. Total cycle: 8-16 weeks.
Evidence Levelstrong_humananimal_plus_anecdotal
A

Sermorelin

Peptides

Mechanism

Sermorelin is a synthetic 29-amino acid peptide representing the biologically active fragment of GHRH (amino acids 1-29) with full functional activity. It activates GHRH receptors on pituitary somatotrophs, stimulating cAMP production via Gs protein/adenylate cyclase and MAP kinase pathways. Due to the interactive effects of sermorelin and endogenous somatostatin, GH release is episodic rather than continuous. Sermorelin also stimulates pituitary gene transcription of GH mRNA, increasing and preserving pituitary GH reserve.

Standard Dosing

Research indicates 200-300 mcg administered once daily at bedtime via subcutaneous injection.

Timing

Bedtime administration (aligns with natural nocturnal GH release). On empty stomach.

Cycle Duration

12-24 week cycles. Some protocols use continuous treatment.

Side Effects

  • Injection site reactions
  • Facial flushing
  • Headache
  • Dizziness
  • Transient taste changes

Contraindications

  • Active cancer
  • Pregnancy and breastfeeding
  • Intracranial hypertension

Best Stacking Partners

IpamorelinGHRP-2GHRP-6

Mechanism

TB-500 is a synthetic fragment of Thymosin Beta-4, a 43-amino acid protein that sequesters G-actin monomers, preventing premature polymerization and facilitating cellular migration and morphological changes essential for wound healing. It upregulates actin to promote cell migration, proliferation, and differentiation of stem/progenitor cells at injury sites. TB-500 also enhances angiogenesis, reduces inflammation, and promotes tissue remodeling through increased re-epithelialization and vascular density.

Standard Dosing

Research indicates 2-2.5 mg administered twice weekly via subcutaneous injection.

Timing

No strict timing requirements. Can be administered at any time of day. Systemic action means injection location is not critical.

Cycle Duration

Loading phase: 4-6 weeks. Total cycle: 8-16 weeks.

Side Effects

  • Temporary lethargy
  • Head rush upon injection
  • Injection site irritation
  • Mild headache

Contraindications

  • Active cancer (angiogenesis concern)
  • Pregnancy and breastfeeding
  • Recent myocardial infarction

Best Stacking Partners

BPC-157GHK-CuGH Secretagogues

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