Thymic DecapeptideT-Cell RestorationIL-2 UpregulationImmunosenescenceLongevity Research
Thymalin is a synthetic decapeptide thymic peptide bioregulator derived from bovine thymus gland extracts. The thymus involutes progressively after puberty, reducing naïve T-cell output and driving immunosenescence. Thymalin restores T-cell function by upregulating IL-2 production, normalising CD4+/CD8+ ratios, and enhancing NK cell cytotoxicity. In aged rodent models, thymalin — particularly in combination with epitalon — has consistently extended lifespan and restored immune parameters toward youthful baselines. It is the primary research tool for thymic peptide-mediated immune rejuvenation.
10 aa
Decapeptide
IL-2
Primary target
CD4/CD8
Ratio restored
Aged models
Longevity tool
≥99%
Purity
Thymalin — Specifications
Property
Value
CAS
74681-68-8
Formula
Decapeptide — thymus extract derived
MW
~878.9 g/mol
Half-life
Short plasma; thymic activity hours
Class
Thymic peptide bioregulator
Purity
≥99% HPLC verified
COA
Janoshik independent third-party
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Mechanism of Action — Thymalin
Thymalin acts through multiple immune pathways without a single characterised receptor:
IL-2 upregulation: Increases IL-2 transcription in T-helper cells — the primary T-cell growth factor whose production declines with age
CD4+/CD8+ restoration: Restores circulating T-cell ratios and naïve T-cell frequency in aged animals
NK cell activation: Enhances natural killer cell cytotoxicity for tumour surveillance and antiviral defence
B-cell support: Enhances antibody production via T-helper cell support — broader than thymosin alpha-1
Thymalin + Epitalon — the foundational longevity combination
Khavinson et al. showed thymalin (immune system) + epitalon (pineal/telomerase) produced greater lifespan extension than either alone in aged mice — 24% vs controls. This combination addresses two primary ageing mechanisms simultaneously: immune senescence and telomere biology.
Key Research Studies & Data
Study
Model
Finding
Khavinson et al. 1997 (Gerontology)
Aged mice — thymalin+epitalon 3mo
Lifespan +24%; immune parameters restored toward young values
Morozov & Khavinson 2000 (Bull Exp Biol Med)
Aged rats IM thymalin
IL-2, CD4+, NK activity restored; thymic weight increased
Peptide Bioregulator series
Multiple aged models
Thymalin+epitalon consistently greatest longevity effect of any peptide combination
Thymalin 1 mg/kg + Epitalon 0.1 mg/kg SC × 10 days monthly in aged mice vs either alone. Same immune panel + lifespan curve, tumour incidence, organ histology.
Protocol 3: Post-immunosuppression recovery
Cyclophosphamide 200 mg/kg IP day 0 → thymalin 1 mg/kg SC days 3-14. WBC recovery kinetics, T-cell subset recovery, IL-2 production, NK cytotoxicity vs vehicle.
Protocol 4: IL-2 induction in vitro
Thymalin 1-100 ng/mL in human PBMC (anti-CD3/CD28). IL-2 ELISA, T-cell proliferation (BrdU), CD25/CD69 activation markers, NFkB p65 nuclear translocation.
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Frequently Asked Questions
What is thymalin?
Thymalin is a synthetic decapeptide thymic peptide bioregulator that restores T-cell function, upregulates IL-2, and reverses immunosenescence markers. Studied in Russian longevity research alongside epitalon.
How does thymalin differ from thymosin alpha-1?
Thymosin alpha-1 has better-characterised TLR9/TLR7 and dendritic cell activation data. Thymalin is the broader thymic bioregulator — more studied for T-cell senescence reversal and longevity combinations. They are complementary.
What is immunosenescence?
Immunosenescence is age-related immune decline: thymic involution, reduced IL-2 production, inverted CD4/CD8 ratio, reduced NK activity, and chronic inflammaging. Thymalin addresses the thymic/T-cell component.
What is the thymalin + epitalon combination?
Thymalin (immune system) + epitalon (pineal/telomerase) addresses two ageing mechanisms simultaneously. The combination shows greater lifespan extension in aged mice than either alone in Khavinson et al. studies.
What formats does QSC supply thymalin in?
QSC supplies thymalin as lyophilised research vials, ≥99% purity HPLC verified with Janoshik COA. Ships from domestic warehouses in USA, EU, UK, Canada, and Australia.
