FOXO4-DRI vs TB-500 (Thymosin Beta-4)

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

FOXO4-DRITB-500 (Thymosin Beta-4)
CategoryPeptidesPeptides
Standard DoseResearch indicates dosing remains experimental. Mouse studies used 5 mg/kg IV, three times weekly.Research indicates 2-2.5 mg administered twice weekly via subcutaneous injection.
TimingNo established timing protocol.No strict timing requirements. Can be administered at any time of day. Systemic action means injection location is not critical.
Cycle DurationMouse studies used intermittent dosing (3x/week for several weeks). Human protocols not established.Loading phase: 4-6 weeks. Total cycle: 8-16 weeks.
Evidence Levelanimal_plus_anecdotalanimal_plus_anecdotal
A

FOXO4-DRI

Peptides

Mechanism

FOXO4-DRI is a D-retro-inverso peptide that selectively targets the FOXO4-p53 protein-protein interaction in senescent cells. In senescence, FOXO4 binds p53's disordered transactivation domain (TAD2) in the nucleus, preventing p53 from translocating to mitochondria where it would trigger apoptosis. FOXO4-DRI competitively disrupts this interaction, causing nuclear exclusion of p53 and its redirection to mitochondria, selectively inducing apoptosis in senescent cells while sparing healthy cells. The D-retro-inverso configuration provides protease resistance.

Standard Dosing

Research indicates dosing remains experimental. Mouse studies used 5 mg/kg IV, three times weekly.

Timing

No established timing protocol.

Cycle Duration

Mouse studies used intermittent dosing (3x/week for several weeks). Human protocols not established.

Side Effects

  • Theoretical: senolytic crisis (rapid senescent cell clearance causing inflammation)
  • Unknown long-term effects in humans
  • Potential cytokine release

Contraindications

  • Active cancer (complex interaction with p53 pathway)
  • Pregnancy and breastfeeding
  • Severe organ failure
  • Immunocompromised state

Best Stacking Partners

EpitalonGHK-CuDasatinib + Quercetin (D+Q senolytic stack)

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

Not sure which is right for you?

Take our free assessment to get personalized recommendations based on your health goals, current stack, and biomarkers.

Get Your Free Protocol →or take the assessment →