≥99%HPLC Purity
COAIncluded
USAShipped
Thymalin Peptide
Thymalin is a synthetic dipeptide bioregulator (Glu-Trp, MW 362.34) derived from calf thymus extracts. It has been studied in published Russian and international literature for thymic peptide bioregulation, T-cell differentiation, and immunomodulatory research in aging models.
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Quick Facts
| SKU | ACR-THYM |
|---|---|
| CAS Number | 38101-59-6 |
| Molecular Formula | C16H18N4O6 |
| Molecular Weight | 362.34 g/mol |
| Sequence | Glu-Trp (L-glutamyl-L-tryptophan) |
| Purity | ≥98% |
| Physical Form | Lyophilized Powder |
| Storage | Store at -20°C |
What is Thymalin?
Thymalin is a polypeptide complex from calf thymus glands, developed by Professor Khavinson. It modulates immune function through T-cell differentiation and maturation, studied for immunosenescence and thymic involution reversal.
Mechanism of Action
Thymalin peptides interact with thymic epithelial cells to promote T-cell maturation. It influences the CD4+/CD8+ ratio, enhances NK cell activity, and normalizes IL-2 and IFN-gamma production in aging models.
Research & Clinical Studies
Geroprotective Study: Thymalin in Elderly and Aging Models
One of the most cited bodies of research on Thymalin concerns its geroprotective potential in elderly subjects and aging animal models. A long-term observational study conducted by Khavinson and colleagues evaluated the effects of Thymalin administration in elderly individuals over multi-year follow-up periods, reporting changes in immunological parameters, infectious morbidity, and overall mortality indices in treated versus control cohorts.[1]
Study Design
- Subjects: Elderly individuals (ages 60-90) stratified into Thymalin-treated and untreated control groups
- Duration: 6-8 year follow-up with periodic Thymalin courses
- Dosing: Intramuscular Thymalin administered in cyclic courses (typically 10 mg/day for 5-10 days, repeated every 4-6 months)
- Endpoints: T-cell subset counts, immunoglobulin levels, infectious episode frequency, mortality
Key Findings
- Restoration of CD3+ and CD4+ T-cell populations toward levels observed in younger reference cohorts
- Reduction in acute respiratory infection frequency reported in the treated group versus controls
- Normalization of CD4/CD8 ratios that typically decline with immunosenescence
- Observational reduction in cumulative mortality reported across the follow-up window
Mechanistic Context
The investigators attributed the observed immunological changes to Thymalin's proposed role as a peptide bioregulator capable of influencing thymic-dependent lymphocyte differentiation. In parallel preclinical work, Thymalin and the related dipeptide Vilon (Lys-Glu) demonstrated effects on lymphoid tissue morphology and gene expression profiles in aged rodents.[2]
It is important to note that much of this literature originates from the St. Petersburg Institute of Bioregulation and Gerontology and was published in Russian-language journals as well as international peer-reviewed outlets. Independent replication of these long-term clinical outcomes remains limited, and all data should be interpreted as preliminary research findings rather than established clinical evidence. Thymalin is studied as a research compound only.
[1] Khavinson VK, Kuznik BI, Ryzhak GA. Peptide bioregulators: a new class of geroprotectors. Communication 1. Results of experimental studies. Advances in Gerontology. 2012;25(4):696-708. PubMed ↗
[2] Anisimov VN, Khavinson VK. Peptide bioregulation of aging: results and prospects. Biogerontology. 2010;11(2):139-149. PubMed ↗
Long-Term Geroprotective Trial: 6-Year Mortality Reduction in Elderly Subjects
One of the most frequently cited investigations of Thymalin is the long-term geroprotective trial conducted by Khavinson and colleagues at the St. Petersburg Institute of Bioregulation and Gerontology. This study followed elderly subjects (mean age 60-75 years) over multiple years of cyclic Thymalin administration and is part of a broader research program examining short peptide bioregulators in age-associated immune decline.
Study Design
- Subjects: 266 elderly individuals randomized into Thymalin, Epithalamin, combined, and control groups
- Duration: 6-8 years of follow-up with cyclic peptide administration
- Dosing protocol: Thymalin administered in courses (typically 10 mg/day for 5-10 days) repeated 1-2 times per year
- Endpoints: All-cause mortality, immunological parameters (T-cell subsets, CD4/CD8 ratio), biomarkers of aging
Key Reported Outcomes
- Reported ~2.0-2.4 fold reduction in mortality in the Thymalin-treated cohort compared to age-matched controls over the observation window
- Normalization of CD3+ and CD4+ T-lymphocyte populations toward values typical of younger adults
- Improvement in CD4/CD8 ratio in subjects exhibiting age-related immunosenescence
- Reduction in incidence of acute respiratory infections during the observation period
- Combined Thymalin + Epithalamin group showed additive effects on lymphocyte normalization, suggesting independent thymic and pineal axis contributions
Mechanistic Context
The investigators proposed that Thymalin's geroprotective signal operates through restoration of thymic hormonal output and modulation of T-cell maturation pathways that decline with thymic involution. In peripheral blood, the peptide preparation has been associated with shifts in lymphocyte differentiation markers consistent with renewed thymopoietic activity, although the precise molecular targets remain an active area of preclinical investigation. Subsequent work from the same group expanded into epigenetic frameworks, proposing that short peptide bioregulators may influence gene expression through interaction with chromatin and specific promoter regions.
Significance and Limitations
This trial is frequently referenced as foundational evidence for the bioregulator class. Methodological caveats noted in the international literature include open-label design, heterogeneous cohort characteristics, and the predominance of single-institution data. Replication in independent centers using modern randomized blinded designs is limited, and findings are reported for research and historical context rather than as clinical recommendations.
Immunomodulatory and Gene Expression Studies in Aging Models
Beyond the long-term mortality cohort, Thymalin has been investigated in a series of mechanistic and translational studies examining how short thymic peptides influence lymphocyte differentiation, cytokine networks, and gene expression in aging immune systems.
T-Cell Differentiation in Aged Subjects
Khavinson and Anisimov reported that Thymalin administration in elderly subjects was associated with shifts in peripheral CD3+, CD4+, and CD8+ subsets toward profiles characteristic of younger immune phenotypes. Functional assays demonstrated improved mitogen-induced lymphocyte proliferation and partial restoration of interleukin-2 (IL-2) production in cultured peripheral blood mononuclear cells. These observations supported the hypothesis that thymic peptide preparations engage with progenitor or peripheral T-cell populations to modulate immunosenescence.
Gene Expression and Epigenetic Modulation
- In vitro studies on cultured human lymphocytes and thymocytes have reported that Thymalin-derived dipeptide signals (Glu-Trp and related sequences) influence expression of genes involved in cell differentiation and apoptosis
- Proposed mechanism involves direct interaction of short peptides with promoter regions or histone-associated DNA, modulating transcriptional accessibility
- Effects have been reported on expression of interferon-gamma, IL-2, and apoptosis-related markers in thymocyte cultures
Comparative Context
Compared with Thymosin Alpha-1 (a 28-amino-acid synthetic peptide with well-characterized TLR-9 and dendritic cell interactions), Thymalin is a small dipeptide signal extracted historically from calf thymus fractions and synthesized as Glu-Trp. The two compounds occupy different mechanistic niches: Thymosin Alpha-1 has extensive randomized clinical data in hepatitis B and sepsis adjuncts, while Thymalin's published literature centers on long-cycle geroprotective administration and immunosenescence research.
Translational Relevance
Subsequent reviews have summarized Thymalin's positioning within the broader Khavinson bioregulator family — including Epithalamin (pineal), Cortexin (cortical), and Prostatilen (prostatic) — proposing a unified framework in which short peptide signals act as tissue-specific transcriptional modulators. While compelling as a research program, this framework remains under active mechanistic investigation, and findings are reported for preclinical and historical research context only.
Chemical & Physical Properties
Thymalin in its synthetic dipeptide form is a low-molecular-weight bioregulator composed of L-glutamic acid and L-tryptophan. The compound is also referred to in the literature as Thymogen when distinguished from the original polypeptide thymic extract, but in modern research catalogs the Glu-Trp dipeptide is most commonly designated Thymalin.
| Full Name | L-Glutamyl-L-Tryptophan (Glu-Trp) |
|---|---|
| Synonyms | Thymogen, Thymalin dipeptide, Glutamyl-Tryptophan |
| Molecular Formula | C₁₆H₁₈N₄O₆ |
| Molecular Weight | 362.34 g/mol |
| CAS Number | 38101-59-6 |
| Sequence | Glu-Trp |
| Amino Acid Count | 2 (dipeptide) |
| Origin / Developer | St. Petersburg Institute of Bioregulation and Gerontology (Khavinson et al.) |
| Classification | Short peptide bioregulator / immunomodulator |
| Physical Form | Lyophilized white powder |
| Solubility | Soluble in bacteriostatic water, sterile water, and saline (0.9% NaCl) |
| Purity | ≥98% (HPLC) |
| Storage | -20°C long-term; 2-8°C short-term after reconstitution |
The simplicity of Thymalin's structure — a single peptide bond between glutamate and tryptophan — confers relatively good stability in lyophilized form. However, the tryptophan residue is sensitive to UV light and oxidative degradation, which has implications for handling and storage (see relevant sections). The compound is structurally distinct from larger thymic peptides such as Thymosin Alpha-1 (28 amino acids) and from the original Thymalin polypeptide thymic extract, though it is hypothesized to mediate a subset of similar bioregulatory functions through receptor-independent peptide signaling mechanisms.
Handling & Reconstitution Guidelines
Thymalin is supplied as a lyophilized powder and requires reconstitution prior to use in laboratory experiments. The following protocol reflects standard handling practices for short peptide bioregulators containing aromatic residues.
Recommended Reconstitution Protocol
- Equilibrate the vial to room temperature for 15-20 minutes before opening to prevent moisture condensation on the lyophilized powder.
- Select diluent: Bacteriostatic water (0.9% benzyl alcohol) or sterile water for injection are both compatible. Sterile 0.9% saline may also be used.
- Determine concentration: For a 10 mg vial, adding 1 mL of diluent yields a 10 mg/mL stock solution. For 5 mg + 1 mL, the resulting concentration is 5 mg/mL.
- Inject diluent slowly down the side of the vial onto the powder cake. Do not aim the stream directly at the lyophilized pellet.
- Swirl gently in a circular motion for 30-60 seconds until the powder is fully dissolved. Do NOT shake or vortex — mechanical agitation can shear peptide bonds and denature aromatic residues.
- Inspect visually: The reconstituted solution should be clear and colorless. Any visible particulates or discoloration indicate degradation or contamination.
- Aliquot for storage if the full vial will not be used within 7-10 days. Use sterile polypropylene tubes to minimize peptide adsorption.
Compound-Specific Notes
- Tryptophan sensitivity: The Trp residue in Thymalin is susceptible to oxidation and UV-induced degradation. Reconstitute in amber vials or protect from direct light during handling.
- Avoid acidic diluents: Strongly acidic solutions can promote tryptophan oxidation. Stick with neutral-pH water or saline.
- Sterile technique: Because Thymalin lacks preservatives in its lyophilized form, use sterile syringes and work in a clean environment to prevent microbial contamination.
- Documentation: Record reconstitution date and concentration directly on the vial for traceability.
Thymalin is intended exclusively for in vitro and laboratory animal research. It is not for human use, food use, or therapeutic application.
Storage & Stability Information
Thymalin (Glu-Trp dipeptide, MW 362.34 g/mol) is supplied as a lyophilized white powder. Although small dipeptides are generally more stable than larger polypeptides, proper storage is essential to preserve research-grade integrity, particularly because the tryptophan residue is susceptible to oxidation and photodegradation.
Lyophilized Powder Storage
- Long-term (recommended): Store at -20°C in a sealed, desiccated environment away from light. Stable for 24+ months under these conditions.
- Short-term: 2-8°C refrigeration is acceptable for up to 30-60 days if the vial remains sealed and protected from humidity.
- Transit: Brief exposure to ambient room temperature (up to 7-10 days) during shipping does not meaningfully degrade the lyophilized dipeptide, provided the vial seal remains intact.
Reconstituted Solution Storage
- After reconstitution in bacteriostatic water or sterile saline, store at 2-8°C and use within 14-21 days for optimal research consistency.
- For longer storage, aliquot the reconstituted solution into single-use volumes and freeze at -20°C; avoid more than one freeze-thaw cycle, as repeated thawing can promote tryptophan oxidation and aggregation artifacts.
- Keep reconstituted vials in amber containers or wrapped in foil to minimize UV exposure of the indole side chain.
Compound-Specific Stability Notes
- Tryptophan oxidation: The indole ring of the Trp residue is the most chemically labile feature of the molecule. Exposure to direct light, oxidizing agents, or elevated temperatures can generate oxidation products (e.g., N-formylkynurenine, kynurenine) that may alter research results.
- Glutamate stability: The N-terminal glutamic acid is chemically robust under standard storage but can undergo cyclization to pyroglutamate over extended periods at neutral pH and elevated temperature.
- Humidity sensitivity: Lyophilized powder is hygroscopic; always equilibrate vials to room temperature before opening to prevent moisture condensation onto the cake.
- Avoid repeated freeze-thaw: Each cycle introduces incremental degradation. Pre-aliquoting upon initial reconstitution is best practice.
All storage guidance is provided for laboratory research handling. Thymalin is supplied strictly for in vitro and preclinical research use and is not intended for human or veterinary application.
Frequently Asked Questions
How does Thymalin differ from Thymosin Alpha-1?
Thymalin is a polypeptide complex while Thymosin Alpha-1 is a single 28-amino acid peptide. Both target immunity but Thymalin works on T-cell maturation, TA1 on dendritic cells and TLR signaling.
What is the molecular weight and CAS number of Thymalin?
The synthetic Thymalin dipeptide (Glu-Trp) has a molecular formula of C16H18N4O6, a molecular weight of 362.34 g/mol, and CAS number 38101-59-6. It is composed of L-glutamic acid bonded to L-tryptophan via a single peptide bond. This compact structure distinguishes Thymalin from larger thymic peptides such as Thymosin Alpha-1 (28 residues, ~3,108 g/mol) and from the original polypeptide thymic extract historically marketed under the same name in Russian clinical literature.
How should Thymalin be stored?
Lyophilized Thymalin should be stored at -20°C for long-term stability, where it remains stable for 24+ months when sealed and protected from light. Short-term storage at 2-8°C is acceptable for several weeks, and brief transit at room temperature does not significantly degrade the lyophilized powder. After reconstitution, store the solution at 2-8°C and use within 7-14 days. The tryptophan residue is light-sensitive, so amber vials or aluminum foil wrapping are recommended for reconstituted solutions. Avoid freeze-thaw cycles of the reconstituted product.
What research has been published on Thymalin?
Thymalin has been studied extensively by Khavinson and colleagues at the St. Petersburg Institute of Bioregulation and Gerontology, with publications in journals including Biogerontology, Bulletin of Experimental Biology and Medicine, and Advances in Gerontology. Research has focused on T-cell differentiation, immunosenescence reversal in aged animal models, cytokine modulation, and long-term geroprotective observational studies in elderly cohorts. Related dipeptide bioregulators studied alongside Thymalin include Vilon (Lys-Glu) and Epithalon (Ala-Glu-Asp-Gly). Independent replication of clinical endpoints outside the originating research group remains limited.
How is Thymalin different from Thymosin Alpha-1?
Thymalin (Glu-Trp) is a synthetic dipeptide with a molecular weight of 362.34 g/mol, while Thymosin Alpha-1 is a 28-amino-acid polypeptide of approximately 3,108 g/mol. Both are studied in the context of thymic immunomodulation, but they differ substantially in structure, proposed mechanism, and research history. Thymosin Alpha-1 has been characterized in extensive Western clinical literature, including TLR signaling studies and infectious disease trials, whereas Thymalin's research base is dominated by the Russian bioregulation school and focuses on dipeptide-mediated gene expression modulation and geroprotection in aging models.
What is Thymalin and what is it used for in research?
Thymalin is a synthetic dipeptide bioregulator with the sequence Glu-Trp (glutamyl-tryptophan), molecular weight 362.34 g/mol and CAS number 38101-59-6. It was originally characterized at the St. Petersburg Institute of Bioregulation and Gerontology as the minimal active fragment of calf thymus peptide extracts. In research settings, Thymalin is studied as an immunomodulator and geroprotector, with published literature examining its effects on T-lymphocyte differentiation, CD4/CD8 ratio normalization, and long-term cyclic administration in aging cohorts. It is supplied strictly for in vitro and preclinical research applications.
How does Thymalin compare to other Khavinson bioregulators like Epithalon?
Thymalin (Glu-Trp) and Epithalon (Ala-Glu-Asp-Gly) are both members of the Khavinson short peptide bioregulator family, but target different organ systems. Thymalin is the thymic dipeptide associated with T-cell differentiation and immunosenescence research, while Epithalon is a pineal-derived tetrapeptide investigated for telomerase activation and circadian/melatonin-axis effects. In the landmark 6-year geroprotective cohort, combined administration of Thymalin and Epithalamin (a related pineal preparation) produced additive effects on lymphocyte normalization, suggesting independent thymic and pineal axis contributions to age-related decline.
What sizes of Thymalin are available from AminoCore Research?
AminoCore Research supplies Thymalin as a lyophilized powder in research-standard vial sizes. Each vial contains ≥98% HPLC-purity Glu-Trp dipeptide and is shipped with a Certificate of Analysis available on request. Specific size options and pricing are listed on the product page variant selector. All material is intended exclusively for in vitro and preclinical laboratory research and is not for human consumption, therapeutic use, or veterinary application.
Does Thymalin require special handling because of the tryptophan residue?
Yes. The tryptophan residue in Thymalin (Glu-Trp) contains an indole side chain that is susceptible to photo-oxidation and chemical oxidation. Researchers handling Thymalin should protect both lyophilized vials and reconstituted solutions from direct light, ideally using amber vials or foil-wrapped containers. Reconstituted solutions should be stored at 2-8°C and used within 14-21 days, or aliquoted and frozen at -20°C to minimize freeze-thaw cycles. Avoid contact with strong oxidizing agents, and equilibrate lyophilized vials to room temperature before opening to prevent moisture absorption by the hygroscopic powder.
For laboratory and research use only. Not intended for human or animal consumption. All product information is derived from published preclinical research and does not constitute medical advice or claims.
