Quick summary
Thymopentin (TP-5) is a synthetic pentapeptide derived from thymopoietin that promotes T-cell maturation and restores cell-mediated immunity. It has been clinically used in Italy for HIV-associated immune deficiency, atopic dermatitis, and rheumatoid arthritis.
Overview
Thymopentin (TP-5) is a synthetic pentapeptide corresponding to residues 32–36 (Arg-Lys-Asp-Val-Tyr) of the thymic hormone Thymopoietin. It is an immunomodulator that promotes T-lymphocyte maturation and restores cell-mediated immune function. Thymopentin has been used clinically in Italy and other countries for HIV infection, atopic dermatitis, and rheumatoid arthritis, though it remains a research compound in the United States.
Mechanism of action
Thymopentin binds to thymopentin receptors on immature lymphoid precursors, inducing differentiation toward CD4+ and CD8+ T-cell phenotypes and expression of T-cell surface markers (including Thy-1). It promotes IL-2 production and T-helper cell activity, enhancing both cellular and humoral immunity. TP-5 also modulates NK cell activity and has been reported to normalize aberrant T-cell subset ratios in immunocompromised patients. Its mechanism reflects the active core of full-length Thymopoietin.
Dosing protocols
| Purpose | Route | Dosage | Frequency | Notes |
|---|---|---|---|---|
| immune modulation (based on clinical trial dosing) | subcutaneous | 50–50 mg | three times weekly for 4–8 weeks (per Italian protocol) | |
| immune modulation (intramuscular) | intramuscular | 50–50 mg | three times weekly |
Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.
Research summary
Multiple clinical trials conducted primarily in Italy and Eastern Europe have evaluated Thymopentin in HIV-infected patients, reporting CD4+ cell count stabilization and reduced infection frequency. Studies in atopic dermatitis showed immune rebalancing and reduced IgE levels. A Phase II trial evaluated TP-5 in rheumatoid arthritis with modest benefit. The compound was approved in Italy (brand: Timopentina) for HIV-associated immune deficiency. No FDA approval has been sought in the United States, where it remains classified as a research compound.[1][2][3][4]
Evidence grading
Each claimed benefit is graded by the strength of available evidence. Grades reflect study quality, not effect size.
Strong = multiple RCTs · Moderate = limited trials or observational · Preliminary = animal or in vitro only · Insufficient = anecdotal or no published data
Side effects
Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.
Common stacks
Peptides commonly paired with Thymopentin for synergistic effects.
Legal status
Thymopentin is approved in Italy (Timopentina) for HIV-associated immune deficiency and is a prescription drug in several European countries. In the US it is not FDA-approved and is classified as a research compound.
Sourcing & access
Research compound
Thymopentin is classified as a research compound. Regulatory status varies by jurisdiction. Always verify current legal status and source from vendors providing third-party certificates of analysis (COA).
Frequently asked questions
Thymopentin (TP-5) is a synthetic pentapeptide (Arg-Lys-Asp-Val-Tyr) corresponding to residues 32-36 of the thymic hormone thymopoietin. It is an immunomodulator that promotes T-lymphocyte maturation and has been approved in Italy under the brand name Timopentina.
Thymopentin binds to receptors on immature lymphoid precursors, inducing differentiation toward CD4+ and CD8+ T-cell phenotypes. It promotes IL-2 production, enhances T-helper cell activity, modulates NK cell function, and can normalize aberrant T-cell subset ratios in immunocompromised patients.
Common side effects include injection site redness, mild fever, transient fatigue, and rare hypersensitivity reactions. It has been used clinically in Italy and Eastern Europe with a documented safety profile from multiple clinical trials.
Clinical trials have evaluated Thymopentin in HIV-infected patients (showing CD4+ cell count stabilization), atopic dermatitis (immune rebalancing and reduced IgE), and rheumatoid arthritis. It is approved in Italy for HIV-associated immune deficiency.
Research references
- Thymopentin (TP-5) immunomodulatory effects: T-cell reconstitutionPubMed
- Thymopentin in immunodeficiency states and HIV infection: clinical trialsPubMed
- Thymopoietin pentapeptide thymopentin and T-lymphocyte subset normalizationPubMed
- Thymopentin clinical use in autoimmune disease and immunodeficiency syndromesPubMed