EVIDENCE MATRIX / THREE FILES
Same Theme. Different Altitudes.
BPC-157, TB-500, and KPV compared by what was tested, where it acted, and how close the evidence came to people.
Read the matrix first
All three compounds are discussed under repair. They do not represent the same kind of evidence. BPC-157 has a broad preclinical program and a tiny human safety record. TB-500 has a major identity problem: the named fragment is supported largely with studies of full-length thymosin beta-4. KPV has a narrow, coherent preclinical program around inflammatory signaling, gut transport, and surface repair, but no human trial.
The comparison therefore uses five checkpoints. Identity asks whether the named molecule matches the tested molecule. Mechanism asks whether a target or pathway is shown. Model names cells, mice, rats, rabbits, or humans. Outcome separates a marker from tissue function. Maturity asks whether controlled human efficacy and meaningful safety data exist.
No compound reaches the top tier. The useful difference is where each ascent stops. BPC-157 stops after minimal human safety observations [1][2]. TB-500 stops partly at the fragment boundary [6][9]. KPV stops after focused animal and cell work [11][13][16].
The evidence matrix
| File | Molecular identity | Primary research lane | Strongest evidence in this corpus | Human evidence | Main unresolved issue |
|---|---|---|---|---|---|
| BPC-157 | Synthetic gastric pentadecapeptide | VEGFR2-linked angiogenesis, nitric oxide, gastric protection | Mixed cell and animal repair models [4][5] | Two-person safety pilot; no repair efficacy [1] | Broad claims outrun a very small human record [2] |
| TB-500 | Ac-LKKTETQ, a seven-amino-acid thymosin beta-4 fragment | Actin-linked cell movement and repair rationale | Structural and regenerative evidence largely for full-length thymosin beta-4 [8][10] | Parent-protein Phase 1 only [9] | Fragment evidence is repeatedly conflated with parent-protein evidence |
| KPV | Lys-Pro-Val, the final three residues of alpha-MSH | PepT1 uptake, NF-kB and MAP-kinase suppression | Cell systems, mouse colitis, targeted delivery, rabbit cornea [11][12][13][14][16] | None in the signed corpus | Human safety, delivery, exposure, and efficacy are untested |
Mechanism is not maturity
BPC-157 presents the broadest repair map. It touches vascular signaling, nitric oxide, stomach protection, cell migration, and growth-related pathways. The VEGFR2 work provides a defined axis [4]. The range is scientifically interesting. It also increases the number of claims that require independent human testing.
TB-500 presents the most familiar structural mechanism. Full-length thymosin beta-4 binds globular actin and controls the pool available for filament formation [10]. Reviews connect that biology with cell migration, scar formation, and angiogenesis [8]. The problem is attribution. TB-500 is only a fragment. A sound parent mechanism does not establish identical fragment behavior.
KPV presents the tightest chain. PepT1 moves the small peptide into inflamed intestinal cells. NF-kB and MAP-kinase activity falls. Cytokine secretion falls. Mouse colitis severity falls [13]. Delivery studies then target the same transporter and tissue state [11][12]. That sequence is coherent. It remains preclinical. Mechanistic clarity can guide a trial. It cannot replace one.
Human evidence: the ceiling
BPC-157 has the only direct human exposure report for the named compound in this corpus. Two healthy adults showed no observed adverse events or measured biomarker changes in a small intravenous pilot [1]. The sample cannot characterize efficacy or a reliable safety profile. A review found only three pilot studies [2].
TB-500 has no completed controlled human trial for the fragment. A forty-volunteer Phase 1 study found full-length thymosin beta-4 well tolerated under its study conditions [9]. It does not transfer automatically to Ac-LKKTETQ.
KPV has no published human trial in the corpus. Its evidence ends with in vitro systems and animal models.
That produces no clinical winner. BPC-157 is marginally higher by direct human exposure, not by proven repair benefit. KPV is stronger in mechanistic coherence, not human maturity. TB-500 carries parent evidence, not fragment confirmation. These are different strengths. None supports medical use.
Claim control
Anecdotal, not clinical evidence, is available for BPC-157 and TB-500 in research-use communities. Reported themes include musculoskeletal recovery, joint comfort, mobility, wound healing, local reactions, fatigue, and other transient symptoms. KPV has no structured signal set in this corpus. Frequency labels describe reporting patterns, not incidence. No comparison of anecdotes can rank efficacy or safety.
The correct research questions follow the gaps. For BPC-157: can a defined repair outcome be reproduced in a controlled human study, and what does longer exposure do? For TB-500: does confirmed Ac-LKKTETQ reproduce any parent-protein effect? For KPV: can a stable formulation produce measurable human exposure and a safe anti-inflammatory signal?
The ascent is not a marketing scale. It is an uncertainty map.