TB4-FRAG (Ac-SDKP) is the naturally occurring active fragment of thymosin beta-4, released by normal enzymatic processing in the body. While TB-500 provides the full range of thymosin beta-4 effects, this fragment concentrates specifically on anti-fibrotic and stem cell regulatory activity.
Research Applications
Key research areas include:
- Cardiac fibrosis: Inhibits collagen I and III deposition in cardiac tissue
- Renal fibrosis: Reduces tubulointerstitial fibrosis in kidney models
- Pulmonary fibrosis: Anti-fibrotic activity in lung tissue
- Hematopoiesis: Maintains stem cell pluripotency
- Inflammation: Reduces macrophage infiltration and inflammatory cytokines
Dosage Information (Research Use)
Research protocols: 100-750 mcg/day subcutaneously. Continuous administration studied in most models (not course-based like some peptides). Research use only.
Reconstitution & Handling
Standard BAC water reconstitution. Small tetrapeptide dissolves instantly.
Half-Life & Pharmacokinetics
Short plasma half-life (degraded by ACE). Functional anti-fibrotic effects persist with consistent dosing.
Reported Observations in Literature
Naturally occurring peptide with good safety profile in animal studies. No significant adverse effects reported at research doses. Endogenous levels are elevated by ACE inhibitor therapy without apparent harm.
Key Research References
- Peng H, et al. “Ac-SDKP reverses cardiac fibrosis in rats with renovascular hypertension.” Hypertension. 2003
- Rasoul S, et al. “Antifibrotic effect of Ac-SDKP and angiotensin-converting enzyme inhibition in hypertension.” J Hypertens. 2004