Immune Peptides

Thymulin

Commonly used for
Immune SupportHealthy Aging
What is it?
Thymulin (Serum Thymic Factor, FTS) is a nonapeptide hormone produced by the thymus that plays a role in T-lymphocyte maturation and immune regulation. It is zinc-dependent for its biological activity.
Mechanism of action: Supports T-lymphocyte differentiation and maturation; Zinc-dependent immunoregulatory activity; May modulate inflammatory cytokine signaling
What do people use it for?
Proposed indications: Immune regulation; T-cell function support; Inflammation
How is it used? / Dosing
Typical clinical dosing schedule: No established clinical dosing. Human use has been limited to early-phase research.
Administration: Subcutaneous or intramuscular injection (research settings) — No established clinical dosing
How does it compare?
Compare with:
How well does it work? / Evidence
? Emerging / limited evidence
An "emerging / limited evidence" rating means rigorous research hasn't caught up yet -- not that this peptide doesn't work. Many peptides in this category are newer or simply understudied rather than proven ineffective.
Evidence rating: ⭐⭐⭐☆☆ — Preclinical and mechanistic research supports a role in T-cell regulation; modern human clinical trial data are limited.
Safety & side effects
Common side effects: Human safety profile remains incompletely characterized.
Serious risks: Unknown long-term safety.
Legal & regulatory status
Legal status: Not FDA-approved for human use. This is a research compound, not a medication — any use should only occur under the direction of a licensed healthcare provider, and its legal availability varies and changes frequently. Verify current status independently before considering use.
Regulatory status: Research peptide • Not FDA approved
Who should avoid it?
Contraindications: Not established. Avoid in:; Pregnancy; Active malignancy; Uncontrolled illness outside research settings
Pregnancy & breastfeeding: Avoid.
Research & references
Bach JF, Dardenne M. (1989). Thymulin, a zinc-dependent hormone. Medical Oncology and Tumor Pharmacotherapy. Dardenne M, Pleau JM. (1994). Interactions between zinc and thymulin. Metal-Based Drugs.