Cyclic

Cyclosporin A

Cyclosporin A is a cyclic non-ribosomal peptide immunosuppressant used in transplant medicine — a landmark natural product peptide drug.

By The Peptides Codex Editorial TeamReviewed July 10, 2026

Length

11 aa

Class

Cyclic

Function

Immunosuppression

Context

Transplant medicine (approved)

Cyclic non-ribosomal peptide — cornerstone of transplant medicine.

Part of the Foundational & therapeutic peptides cluster

Overview

Cyclosporin A is a cyclic non-ribosomal peptide immunosuppressant used in transplant medicine — a landmark natural product peptide drug.

Source & context

Biological / chemical source: Fungus (Tolypocladium)

Primary research or clinical context: Transplant medicine (approved)

Non-ribosomal synthesis

Unlike ribosomal peptides, cyclosporin is assembled by non-ribosomal peptide synthetases and includes non-proteinogenic residues — expanding what 'peptide drug' can mean.

FAQ about Cyclosporin A

What is Cyclosporin A?+

Cyclosporin A is a cyclic non-ribosomal peptide immunosuppressant used in transplant medicine — a landmark natural product peptide drug.

Is Cyclosporin A an approved medicine?+

Cyclosporin A: Transplant medicine (approved). Always follow licensed medical guidance for approved products.

What is the typical length of Cyclosporin A?+

Cyclosporin A is commonly described as approximately 11 amino acids (Cyclic).

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SNAP-8

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Follistatin-344

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Follistatin-344 (FS-344) is the 344-amino-acid precursor isoform of follistatin, an activin-binding protein encoded by the FST gene. It antagonizes TGF-β superfamily ligands such as myostatin and activin, making it a focus of muscle-biology research. It is not an approved therapeutic in Canada.

References & further reading

Disclaimer: Educational content only. Not medical advice. Not instructions for human use. Research peptides and unapproved products may be restricted or illegal to market for human consumption in your jurisdiction. Consult qualified professionals and applicable law.

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Cite this: Peptides Codex — Cyclosporin A educational profile.

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