This page compares what is documented about TB-500 and Thymosin Alpha-1, 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 Everything here is research-use-only material and we do not publish outcome, dosing or administration content for any compound in the catalogue.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 TB-500 and what is Thymosin Alpha-1?
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.
Thymosin Alpha-1. Thymosin alpha-1 is a 28-amino-acid peptide originally isolated from thymic tissue, and it has one of the longer continuous publication records of any peptide in immunological research.
How do TB-500 and Thymosin Alpha-1 compare on price and size?
| TB-500 | Thymosin Alpha-1 | |
|---|---|---|
| Sizes carried | 5 mg, 10 mg | 5 mg, 10 mg |
| From | $54.00 | $70.00 |
| Best price per unit | $6.00 / mg | $13.00 / mg |
| Availability | Backordered — waitlist | Backordered — waitlist |
| Certificate | Lot certificate on the product page | Lot certificate on the product page |
| Molecular formula | C38H68N10O14 | C129H215N33O55 |
| Molar mass | 889 g/mol | 3,108.3 g/mol |
| Source | PubChem CID 62707662 | PubChem CID 16130571 |
| Research area | actin-regulation research | immunological research |
At their best sizes TB-500 works out at $6.00 per mg against $13.00 for Thymosin Alpha-1 — 2.2 times more for the mg. Vial prices start at $54.00 and $70.00 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 TB-500 page and the Thymosin Alpha-1 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.
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.
Thymosin Alpha-1 is studied in immunological research. Thymic peptides have been studied continuously since the 1970s, and the identity and purity methods have moved further than the biology in that time.
Studied in the same area does not make two compounds interchangeable, and the research library holds the per-compound documentation.
Thymosin Alpha-1 vs TB-500: how they differ on the bench
Thymosin Alpha-1. Short, well-characterised sequences are the easiest to verify and the easiest to mislabel, which is why every lot carries a certificate you can read rather than a claim you have to trust.
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.
What actually differs between Thymosin Alpha-1 and TB-500
Worth doing the arithmetic before comparing sizes: Thymosin Alpha-1 is 3,108.3 g/mol and TB-500 is 889 g/mol, a factor of 3.5. A milligram of TB-500 therefore contains roughly 3.5 times as many molecules as a milligram of Thymosin Alpha-1, 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. 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, Thymosin Alpha-1 or TB-500?
Neither Thymosin Alpha-1 nor TB-500 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:
- TB-500 is the cheaper of the two per mg, at $6.00 against $13.00.
- Thymosin Alpha-1 is the heavier molecule by a factor of 3.5, so equal milligrams are not equal moles.
- Both are carried in 2 sizes, and each lot carries its own certificate.
Every one of those is checkable before you buy.
Common questions
What is the difference between Thymosin Alpha-1 and TB-500?
Different molecules before anything else: Thymosin Alpha-1 is C129H215N33O55 and TB-500 is C38H68N10O14. Thymosin alpha-1 is a 28-amino-acid peptide originally isolated from thymic tissue, and it has one of the longer continuous publication records of any peptide in immunological research. 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.
Which one should I choose?
TB-500 is carried in 5 mg, 10 mg and Thymosin Alpha-1 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 TB-500 and Thymosin Alpha-1 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, Thymosin Alpha-1 or TB-500?
Per mg, TB-500 at $6.00 against $13.00, taking each one's best size. By vial they start at $54.00 for TB-500 and $70.00 for Thymosin Alpha-1, 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 TB-500 the same as a milligram of Thymosin Alpha-1?
By mass yes, by amount of substance no. Thymosin Alpha-1 is 3,108.3 g/mol and TB-500 is 889 g/mol, a factor of 3.5, so a milligram of TB-500 holds roughly 3.5 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.