Thymulin
Also known as: Facteur Thymique Serique, FTS, Zinc-thymulin
Overview
Thymulin (facteur thymique sérique, FTS) is a nonapeptide hormone produced exclusively by thymic epithelial cells, characterized by its unique zinc-binding requirement for biological activity. Thymulin circulates in blood in free (inactive) and zinc-bound (active) forms. Its levels decline progressively from adolescence through advanced age, correlating with thymic involution and immunosenescence. Research demonstrates roles in T-cell maturation, anti-inflammatory cytokine regulation, NF-κB modulation, and potential thymic rejuvenation in aging.
Mechanism of Action
Thymulin binds to T-cell surface receptors (zinc-dependent interaction) activating calcium signaling, MAPK pathway activation, and downstream transcription factor nuclear translocation influencing T-cell survival, differentiation, and cytokine production. It modulates NF-κB signaling (IKK phosphorylation inhibition) reducing inflammatory cytokines including IL-1β, IL-2, IL-6, TNF-alpha, IFN-gamma. It also suppresses HSP70 overproduction in inflammatory states. Zinc coordination through specific amino acid residues is essential for receptor binding.
Potential Benefits
- T-cell development and maturation support in the thymus
- Anti-inflammatory via NF-κB inhibition and cytokine modulation
- Prevention of overproduction of pro-inflammatory cytokines in sepsis models
- Restoration of T-cell counts in immunosenescent animals
- Vaccine adjuvant activity enhancing antibody responses in aged mice
- Reduced severity in autoimmune encephalomyelitis (MS model)
- Bidirectional neuroendocrine-immune communication
Dosage Protocols
The following reflects doses used in published research studies. This is not medical advice. Consult a qualified healthcare professional.
| Beginner | 100 mcg 2x weekly |
| Intermediate | 250 mcg 2-3x weekly |
| Advanced | 500 mcg 3x weekly |
| Cycle Duration | 4-8 weeks |
Zn-bound nonapeptide. T-cell differentiation modulator. Requires zinc cofactor for bioactivity.
Use our Reconstitution Calculator to determine exact syringe units for your protocol.
Routes of Administration
Subcutaneous Injection High
Standard route. Ensure adequate zinc status.
Read our full Routes of Administration Guide for detailed comparison of all delivery methods.
Stacking Protocols
Popular research stacks involving Thymulin:
Thymic Support Stack
Multi-peptide thymic function support for immunosenescence.
Explore our complete Peptide Stacking Guide for more combinations and safety considerations.
Reconstitution
| Storage | Refrigerate at 2-8°C after reconstitution. Do not freeze reconstituted solution. |
|---|
Typical vial sizes: 1-5 mg. Add bac water slowly down the side of the vial, swirl gently — do not shake. Use insulin syringe for precise dosing.
Need exact syringe measurements?
Amino Acid Sequence
Pyr-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn (with pyroglutamic acid N-terminus, zinc-bound)
Side Effects & Safety
- Generally well-tolerated at therapeutic doses
- Low toxicity profile
- Injection site reactions
Safety & Contraindications
This information is for educational purposes only. Consult a qualified healthcare provider before using any peptide.
Pregnancy / Lactation
Bleeding Disorders
Active Skin Infection at Injection Site
Pharmacokinetics
| Half-Life | Not well characterized for this peptide; consult primary literature |
|---|---|
| Storage | Store lyophilized peptide at -20°C (long-term) or 2-8°C (short-term, under 30 days). Reconstituted: refrigerate at 2-8°C and use within 28-30 days. Protect from light. Do not freeze reconstituted solution. |
Synergistic Compounds
The following compounds have been studied alongside Thymulin for potential complementary or synergistic effects:
Learn More
References & Further Reading
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