Thymosin Beta-4 Fragment (Ac-SDKP)
Also known as: N-Acetyl-Ser-Asp-Lys-Pro, Acetyl-N-Ser-Asp-Lys-Pro, Goralatide
Overview
Ac-SDKP (N-acetyl-seryl-aspartyl-lysyl-proline) is a naturally occurring tetrapeptide released from thymosin beta-4 by prolyl oligopeptidase and ACE2 cleavage. It is a powerful regulator of hematopoietic stem cell proliferation, inhibiting entry of pluripotent hematopoietic stem cells into the S-phase of the cell cycle—protecting them from cycle-dependent cytotoxic damage during chemotherapy. Ac-SDKP also exerts significant antifibrotic effects in the heart, kidneys, and lungs, and is hydrolyzed by ACE (angiotensin-converting enzyme), explaining why ACE inhibitors elevate plasma Ac-SDKP levels.
Mechanism of Action
Ac-SDKP acts through multiple mechanisms: (1) Hematopoietic stem cell cycle arrest—inhibits G0-S transition via BMP4/SMAD pathway suppression, protecting stem cells from S-phase cytotoxic chemotherapy; (2) Antifibrotic—suppresses TGF-β1-induced myofibroblast differentiation and collagen synthesis in cardiac and renal fibroblasts; (3) Anti-inflammatory—reduces macrophage activation and TNF-α/IL-6 production; (4) Angiogenic—promotes endothelial cell migration and tube formation. Its ACE-mediated hydrolysis links it to the renin-angiotensin system.
Potential Benefits
- Bone marrow stem cell protection during chemotherapy
- Cardiac and renal antifibrotic activity
- Anti-inflammatory via macrophage and cytokine modulation
- Elevates naturally with ACE inhibitor use
- Potential in heart failure, kidney disease, and lung fibrosis
Dosage Protocols
The following reflects doses used in published research studies. This is not medical advice. Consult a qualified healthcare professional.
| Beginner | Not a consumer peptide — research only |
| Intermediate | N/A |
| Advanced | N/A |
| Cycle Duration | Preclinical cardiac/fibrosis models: weeks |
Ac-Ser-Asp-Lys-Pro tetrapeptide. Endogenous hematopoiesis and antifibrotic regulator — released from Thymosin Beta-4.
Use our Reconstitution Calculator to determine exact syringe units for your protocol.
Routes of Administration
Subcutaneous or IV (research) High but very short half-life
Rapidly degraded by ACE — often studied with ACE inhibitor co-administration.
Read our full Routes of Administration Guide for detailed comparison of all delivery methods.
Stacking Protocols
Popular research stacks involving Thymosin Beta-4 Fragment (Ac-SDKP):
Explore our complete Peptide Stacking Guide for more combinations and safety considerations.
Reconstitution
| Storage | Refrigerate at 2-8°C after reconstitution. Do not freeze reconstituted solution. |
|---|
Typical vial sizes: 1-5 mg (research). Add bac water slowly down the side of the vial, swirl gently — do not shake. Use insulin syringe for precise dosing.
Need exact syringe measurements?
Amino Acid Sequence
Ac-Ser-Asp-Lys-Pro
Side Effects & Safety
- Well-tolerated in clinical studies
- Potential excess stem cell cycle suppression at very high doses
Safety & Contraindications
This information is for educational purposes only. Consult a qualified healthcare provider before using any peptide.
Pregnancy / Lactation
Bleeding Disorders
Active Skin Infection at Injection Site
Pharmacokinetics
| Half-Life | ~4-5 minutes (degraded by ACE) |
|---|---|
| Storage | Store lyophilized peptide at -20°C (long-term) or 2-8°C (short-term, under 30 days). Reconstituted: refrigerate at 2-8°C and use within 28-30 days. Protect from light. Do not freeze reconstituted solution. |
Synergistic Compounds
The following compounds have been studied alongside Thymosin Beta-4 Fragment (Ac-SDKP) for potential complementary or synergistic effects:
Learn More
References & Further Reading
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