Immune · Investigational
Thymostimulin (TP-1)
No lawful US pathway
01 · Overview
Thymostimulin (TP-1) is a partially purified extract of calf thymus consisting of a mixture of polypeptides (PMID 2058819). It is thought to promote T-lymphocyte maturation by mimicking thymic hormone activity, and it was used as an immune response modifier in primary and secondary immunodeficiencies.
Because it is a bovine-derived product, severe allergic reactions, including anaphylaxis, have been reported (PMID 2058819).
02 · Research summary & key findings
A Cochrane review of randomized trials found that adding thymus extracts such as thymostimulin to chemotherapy or radiotherapy did not improve survival or tumor response, though there was preliminary evidence of fewer severe infections (PMID 21328265). In advanced liver cancer, an encouraging phase II trial (PMID 18366627) was followed by a randomized, placebo-controlled phase III trial that found no survival benefit (PMID 20735834). Interest has since declined given the lack of standardized composition and negative controlled trials.
03 · Regulatory status
Thymostimulin (TP-1) is in the investigational stage. While preclinical and early-phase data exist, it has not received regulatory approval for clinical use in the United States.
No lawful pathway today
Thymostimulin (TP-1) is not FDA-approved and does not currently have a lawful prescription or compounding pathway in the United States, so we do not sell it and will not book a consultation for it. That can change: in 2026 FDA began reviewing several peptides for compounding.
See the 1 FDA-approved compound in Immune
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04 · Administration routes
- Intramuscular injection
- Subcutaneous injection
References
- [1]Thymostimulin in advanced hepatocellular carcinoma: a phase II trial BMC Cancer, 2008. PMID 18366627
- [2]Severe anaphylactic reaction to thymostimulin Allergy, 1991. PMID 2058819
- [3]Thymostimulin versus placebo for palliative treatment of locally advanced or metastasised hepatocellular carcinoma: a phase III clinical trial BMC Cancer, 2010. PMID 20735834
- [4]Thymic peptides for treatment of cancer patients Cochrane Database Syst Rev, 2011. PMID 21328265
Primary literature
- PubMed: "Thymostimulin"
Peer-reviewed literature indexed by the National Library of Medicine.
- ClinicalTrials.gov: "Thymostimulin"
Registered interventional and observational studies, including status and phase.
- PubChem: "Thymostimulin"
Chemical structure, molecular properties, and bioactivity data.
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