This page compares what is documented about KPV and TB-500, rather than ranking them by effect. What each molecule is, the sizes and prices actually carried, what the certificate covers, and how the two differ on the bench. Everything here is research-use-only material and we do not publish outcome, dosing or administration content for any compound in the catalogue.
What is KPV and what is TB-500?
KPV. KPV is the C-terminal tripeptide of alpha-MSH, studied in gut-epithelium and inflammation models for its receptor-independent activity — three residues with a serious citation trail.
TB-500. TB-500 maps to the actin-binding domain of thymosin beta-4, a protein studied across cell-migration and repair-model research for two decades.
How do KPV and TB-500 compare on price and size?
| KPV | TB-500 | |
|---|---|---|
| Sizes carried | 10 mg | 5 mg, 10 mg |
| From | $49.00 | $54.00 |
| Best price per unit | $4.90 / mg | $6.00 / mg |
| Availability | Backordered — waitlist | Backordered — waitlist |
| Certificate | Lot certificate on the product page | Lot certificate on the product page |
| Molecular formula | C16H30N4O4 | C38H68N10O14 |
| Molar mass | 342.43 g/mol | 889 g/mol |
| Source | PubChem CID 125672 | PubChem CID 62707662 |
| Research area | inflammation-model research | actin-regulation research |
At their best sizes KPV works out at $4.90 per mg against $6.00 for TB-500 — 22% more for the mg. Vial prices start at $49.00 and $54.00 respectively, which is the number most people compare and the one that says least, because the two are not sold in the same sizes. Full sizes, tier pricing and the lot certificate sit on the KPV page and the TB-500 page.
What is each one studied for?
What the published literature investigates, which is a different question from what either will do, and the only one of the two a supplier can answer.
KPV is studied in inflammation-model research. Inflammation-model research keeps returning to alpha-MSH fragments, with KPV the most-studied of the C-terminal set.
TB-500 is studied in actin-regulation research. Actin-regulation research keeps thymosin beta-4 and its fragments in steady rotation across cell-migration studies.
Studied in the same area does not make two compounds interchangeable, and the research library holds the per-compound documentation.
TB-500 vs KPV: how they differ on the bench
TB-500. TB-500 in solution is a different molecule, stability-wise, than the sealed lyophilisate — date the vial the moment BAC water touches it.
KPV. A tripeptide leaves nowhere for impurities to hide on a chromatogram — KPV purity results are among the cleanest reads in the catalog.
What actually differs between TB-500 and KPV
Worth doing the arithmetic before comparing sizes: TB-500 is 889 g/mol and KPV is 342.43 g/mol, a factor of 2.6. A milligram of KPV therefore contains roughly 2.6 times as many molecules as a milligram of TB-500, so two vials of the same labelled mass hold quite different amounts of substance. Equal milligrams are not equal moles, which is what the molarity calculator exists to convert, and it is the reason a price-per-milligram comparison and a price-per-mole comparison can point at different vials.
Identity is the other analytical axis, and it is settled per lot rather than per compound. KPV. Catalogued as Lys-Pro-Val, and the certificate's identity test resolves to that. TB-500. Catalogued as TB-500, and the certificate's identity test resolves to that.
Both are released against a certificate reporting identity, purity by the stated method and net peptide content, readable before anything is bought.
Which is better, TB-500 or KPV?
Neither TB-500 nor KPV is ranked against the other here, and the refusal is deliberate. Better, safer and stronger are questions about effects in a living system, and we sell neither compound for use in one — why none of these pages ranks two compounds sets out the reasoning in full.
What it does instead, for these two:
- KPV is the cheaper of the two per mg, at $4.90 against $6.00.
- TB-500 is the heavier molecule by a factor of 2.6, so equal milligrams are not equal moles.
- KPV is carried in 1 size and TB-500 in 2, and each lot carries its own certificate.
Every one of those is checkable before you buy.
Common questions
What is the difference between TB-500 and KPV?
Different molecules before anything else: TB-500 is C38H68N10O14 and KPV is C16H30N4O4. TB-500 maps to the actin-binding domain of thymosin beta-4, a protein studied across cell-migration and repair-model research for two decades. KPV is the C-terminal tripeptide of alpha-MSH, studied in gut-epithelium and inflammation models for its receptor-independent activity — three residues with a serious citation trail.
Which one should I choose?
KPV is carried in 10 mg and TB-500 in 5 mg, 10 mg, each lot with its own certificate. Which of those suits the work is yours to decide; everything here is research-use-only rather than guidance for use in a human or an animal.
Do both KPV and TB-500 come with a certificate of analysis?
Neither is in stock at the moment, so in each case the certificate is the one attached to the lot that arrives. A certificate belongs to a lot, not to a product. It is linked from the product page, and reports identity, purity by the stated method, and net peptide content for the material actually in that lot.
Which is cheaper, TB-500 or KPV?
Per mg, KPV at $4.90 against $6.00, taking each one's best size. By vial they start at $49.00 for KPV and $54.00 for TB-500, which is the comparison most people make and the one that says least, because the two are not sold in the same sizes.
Is a milligram of KPV the same as a milligram of TB-500?
By mass yes, by amount of substance no. TB-500 is 889 g/mol and KPV is 342.43 g/mol, a factor of 2.6, so a milligram of KPV holds roughly 2.6 times as many molecules. Two vials with the same number on the label are not the same amount of substance, which is what the molarity calculator converts.
FOR LABORATORY AND IN-VITRO RESEARCH USE ONLY. NOT FOR HUMAN OR ANIMAL CONSUMPTION. NOT FOR PERSONAL, MEDICAL, DIAGNOSTIC, THERAPEUTIC, OR RECREATIONAL USE.