Is Ac-SDKP FDA approved?

Ac-SDKP is not evaluated or approved by the FDA. It is discussed for research and educational purposes only, not as medical guidance.

Is Splenin FDA approved?

Splenin is not evaluated or approved by the FDA. It is discussed for research and educational purposes only, not as medical guidance.

How is Ac-SDKP administered in research settings?

In research settings, Ac-SDKP is typically administered via the subcutaneous or intravenous routes. PeptideBase does not provide dosing or administration instructions.

How is Splenin administered in research settings?

In research settings, Splenin is typically administered via the subcutaneous or intramuscular routes. PeptideBase does not provide dosing or administration instructions.

Home›Research›Compare›Ac-SDKP vs Splenin

Peptide Comparison

Ac-SDKP vs Splenin

Q: What is the difference between Ac-SDKP and Splenin?

Ac-SDKP: Inhibits hematopoietic stem cell entry into S-phase. Blocks TGF-β1-mediated fibroblast activation, reducing collagen deposition. Promotes angiogenesis via VEGF upregulation. Regulated in vivo by ACE enzyme. Splenin: Spleen-derived tetrapeptide bioregulator; normalizes leukocyte and platelet production; modulates splenic immune cell activity

Ac-SDKP

N-acetyl-seryl-aspartyl-lysyl-proline

RecoveryNot EvaluatedResearch Only

No providers listed yet

Full Ac-SDKP profile →

Splenin

Spleen peptide bioregulator

RecoveryNot EvaluatedResearch Only

Half-life: Unknown

1 providers listed

Full Splenin profile →

Bottom line

Ac-SDKP and Splenin target different goals — Ac-SDKP for anti-fibrotic, Splenin for immune restoration. They're compared here for reference, not as direct substitutes.

Quick Verdict

Ac-SDKP

Splenin

Different Goals

Ac-SDKP and Splenin target different goals — Ac-SDKP for Tissue Repair, Splenin for Immune & Thymic. They're compared here for reference; there isn't a single “better” choice between them.

Side-by-Side Comparison

Ac-SDKP

Splenin

Mechanism Family

Tissue Repair

Immune & Thymic

Half-life

—

Unknown

FDA Status

not evaluated

Admin Routes

subcutaneous, intravenous

subcutaneous, intramuscular

Availability

Research Only

Providers

None listed

1 listed

Avail. Notes

—

Russian peptide bioregulator from spleen (Khavinson Institute). Immunomodulatory. No FDA approval, no NDA or IND. Not on any FDA list. Research chemical in US only.

Research Evidence

Ac-SDKP

Animal · 3 key studies · most recent 2026

Splenin

Review · 2 key studies · most recent 2022

Research Citations

Ac-SDKP

Animal2026 · Biomater Adv

Device surface-functionalized ac-SDKP nanoassemblies accelerate endothelial recovery through dual anti-inflam…

Animal2015 · American Journal of Physiology: Renal Physiology

N-Acetyl-Seryl-Aspartyl-Lysyl-Proline: mechanisms of renal protection in mouse model of systemic lupus erythe…

Animal2013 · Kidney International

Thymosin β4 and its degradation product, Ac-SDKP, are novel reparative factors in renal fibrosis

Splenin

Review2022 · International Journal of Molecular Sciences

Neuroepigenetic Mechanisms of Action of Ultrashort Peptides in Alzheimer's Disease

Review2020 · Stem Cell Reviews and Reports

Peptide Regulation of Cell Differentiation

About Ac-SDKP

Inhibits hematopoietic stem cell entry into S-phase. Blocks TGF-β1-mediated fibroblast activation, reducing collagen deposition. Promotes angiogenesis via VEGF upregulation. Regulated in vivo by ACE enzyme.

Research Areas

anti-fibroticcardiac repairwound healingkidney protection

About Splenin

Spleen-derived tetrapeptide bioregulator; normalizes leukocyte and platelet production; modulates splenic immune cell activity

Research Areas

immune restorationblood cell productionsplenic function support

Safety Profile

Information below reflects published research data only — not medical advice. Consult a qualified provider before use.

Ac-SDKP

No established clinical contraindications. This is an investigational compound with limited human data and has not been evaluated by the FDA for safety in this context. Consult a qualified clinician.

Splenin

No established clinical contraindications. This is an investigational compound with limited human data and has not been evaluated by the FDA for safety in this context. Consult a qualified clinician.

Find Providers

Where to source these peptides

Providers offering

Ac-SDKP

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Providers offering

Splenin

1 listed

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PeptideBase lists providers for educational research purposes only. Always consult a qualified healthcare professional before obtaining or using any peptide.

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Educational research tools — not medical advice.