# Thymulin (FTS)

> Thymulin (FTS) — nine-residue thymic peptide whose activity requires zinc

All products are sold strictly for laboratory research use only. Not for human or veterinary use.

- Web page: https://peptidemedixeu.com/en/products/thymulin/
- Brand: Peptide Medix EU
- Category: [Immune Peptides](https://peptidemedixeu.com/en/collections/immune-peptides/)
- Purity: ≥99% by HPLC; lot-matched COA available
- CAS number: 63958-90-7
- from €76 (EUR)

## Sizes and prices (EUR)

| Size | Price | SKU |
| --- | --- | --- |
| 5 mg | €76 | THYMULIN-5-MG |
| 10 mg | €131 | THYMULIN-10-MG |

_Catalog prices at build time; the web page and checkout are authoritative._

## Specifications

- **CAS number:** 63958-90-7
- **Molecular formula:** C33H54N12O15
- **Molecular weight:** 858.83 g/mol
- **Amino acid sequence:** Pyr-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn
- **Chain length:** 9 amino acids, N-terminal pyroglutamate
- **Form:** Lyophilized powder, sealed glass vial with crimped stopper
- **Purity:** ≥99% by HPLC; lot-matched COA available
- **Available sizes:** 5 mg, 10 mg
- **Storage (lyophilized):** −20 °C, sealed and protected from light and moisture
- **Other names:** FTS, facteur thymique sérique, serum thymic factor
- **Metal dependence:** Activity reported only in the zinc-bound form
- **Source:** Produced natively by thymic epithelial cells
- **Research areas:** Zinc status and immunity, thymic involution, neuroendocrine-immune interaction

## Description

Thymulin — known in older papers as facteur thymique sérique, or FTS — is a nonapeptide secreted by the epithelial cells of the thymus. What defines it is an absolute need for metal: without a bound zinc ion the peptide does nothing, and only the zinc complex is active. This property, set out in the foundational work of the 1970s and 1980s, is why the zinc-bound form sometimes appears as a separate entity.

Because circulating thymulin activity mirrors zinc status, the peptide has kept a lasting place in immunology. Research on zinc deficiency, on the thymus shrinking with age and on hormonal influences on thymic function all rely on thymulin activity as a readout — making it a reagent with a defined analytical job, not merely an object of study.

We make it by solid-phase synthesis, purify it to ≥99% by reversed-phase HPLC and supply it as lyophilised powder in sealed 5 mg and 10 mg vials, each lot with its certificate of analysis. Bear in mind that the vial contains the peptide alone; whether zinc is present in your experiment depends on your buffer and design. For laboratory research only.

## Frequently asked questions

### What is Thymulin?

A nonapeptide made by thymic epithelial cells, historically named facteur thymique sérique (FTS). We supply it as a lyophilised research powder for studies of zinc status, thymic involution and neuroendocrine–immune interactions.

### Why does zinc matter so much?

According to published research, the peptide is inactive by itself and becomes active only after forming a 1:1 complex with a zinc ion. This dependence is why nutritional immunologists have used thymulin activity as a functional gauge of how much zinc is available.

### Is zinc included in the vial?

No — you receive the peptide only. Whether the active zinc complex forms in your experiment depends on trace metals in your buffer and any chelators you use, so it becomes a matter of study design, not of product specification.

### How is Thymulin different from Thymalin?

Thymulin is one defined nonapeptide whose sequence, formula and mass can all be checked analytically. Thymalin is a complex of numerous thymic polypeptides with no single structure. They come from the same tissue but cannot be swapped for each other in research.

### What purity do you guarantee, and is there a COA?

Every lot is purified and analysed by reversed-phase HPLC to ≥99%, with its mass checked against the expected 858.83 g/mol. The certificate carrying the lot number on your vial can be requested before or after you order.

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All products offered on this website are intended solely for in-vitro laboratory research and development by qualified professionals. They are not drugs, foods, cosmetics or dietary supplements, and are not intended to diagnose, treat, cure or prevent any disease. Products must not be introduced into humans or animals in any manner. By purchasing, you confirm that you are a qualified researcher and accept full responsibility for handling and storage in accordance with applicable laws.

Peptide Medix EU · https://peptidemedixeu.com/en/products/thymulin/