Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of KPV and Thymosin Alpha-1 — mechanism, side effects, legal status, and pricing.
KPV (Lys-Pro-Val) is the C-terminal tripeptide of alpha-melanocyte-stimulating hormone (alpha-MSH residues 11-13), the smallest alpha-MSH fragment retaining anti-inflammatory activity. Research-only; not FDA-approved. Evidence is primarily preclinical with no controlled human trials.
Thymosin Alpha-1 (Tα1) is a 28-amino-acid acetylated peptide (Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN) corresponding to the N-terminus of prothymosin α. Marketed as Zadaxin / thymalfasin and approved in 35+ countries for chronic hepatitis B/C and as an immune adjuvant, but NOT FDA-approved in the US — Phase 3 HCV trials ended without approval. Outside the US it is one of the most clinically validated immune-modulating peptides.
KPV
Thymosin Alpha-1
Category
Legal Status
Mechanism
Half-life
Side Effects
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
KPV
Thymosin Alpha-1
COA corpus from Disclosed Labs — independently tested batches only.
KPV
89
COAs
99.5%
Avg purity
15
Labs
Thymosin Alpha-1
69
COAs
99.6%
Avg purity
12
Labs
Dalmasso et al. (Gastroenterology 2008; PMID 18061177) demonstrated PepT1-mediated uptake of KPV and reduction of DSS- and TNBS-induced colitis in mice. Kannengiesser et al. (Inflammatory Bowel Diseases 2008; PMID 18092346) showed anti-inflammatory effects in two murine colitis models at least partly independent of MC1R signaling. Brzoska et al. (Endocrine Reviews 2008; PMID 18612139) reviewed alpha-MSH and related tripeptides, summarizing NF-kB suppression across cell types. Subsequent preclinical work (largely from the Merlin group at Georgia State) has explored oral nanoparticle and polysaccharide-hydrogel delivery for IBD. No controlled human trials have been published.
Key references
Thymosin alpha-1 has been studied in 90+ clinical trials. A meta-analysis by Yang et al. (Antiviral Research 2008, PMID 18078676) in chronic hepatitis B found antiviral efficacy comparable to interferon-alpha. Tuthill, Rios & McBeath (Ann N Y Acad Sci 2010, PMID 20536460) reviewed the global Zadaxin program across HBV, HCV, melanoma, HCC, and vaccine adjuvancy. Romani et al. (Blood 2006, PMID 16741252) established the TLR9 / IDO dendritic-cell mechanism that underlies Ta1's dual pro-inflammatory / tolerogenic effects. During the COVID-19 pandemic, Liu et al. (Clin Infect Dis 2020, PMID 32442287) reported reduced mortality (11.11% vs 30.00%, p=0.044) in severe lymphopenic COVID-19 patients via restoration of exhausted T cells. A 2024 systematic review by Dinetz & Lee (Altern Ther Health Med, PMID 38308608) covering 30+ trials and 11,000+ subjects concluded Ta1 is a well-tolerated and effective immune modulator, and argued the FDA's 2023 restriction appeared unfounded given the clinical evidence. US regulatory status: NOT FDA-approved; removed from 503A Category 2 in September 2024 after nominator withdrawal; PCAC voted AGAINST inclusion on the 503A Bulks List on December 4, 2024.
KPV and Thymosin Alpha-1 are both in the Immune category and may have overlapping mechanisms. Researchers should review both profiles carefully, understand the mechanisms of action, and monitor the relevant biomarkers when combining compounds in the same class. As always, consult a licensed healthcare provider before making any decisions about combining research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Contraindications
Lab Testing
Key references
Disclosed Labs