Thymosin Alpha-1 is a 28-residue peptide, which puts it in a different class from the three- and four-residue sequences that make up much of the search demand for research peptides. The checks a buyer should run on a listing change accordingly. Sequence errors are harder to spot by eye, the terminal modification matters as much as the residues, and a milligram figure covers roughly ten times fewer molecules than the same figure on a tripeptide vial. This guide is for a United States laboratory deciding where to buy Thymosin Alpha-1: what the compound is, what to look for on any listing, how our 5 mg vial is specified and priced, and how it is shipped and paid for.
The sequence and the acetyl group
Thymosin Alpha-1 is the N-terminally acetylated 28-residue peptide Ac-Ser-Asp-Ala-Ala-Val-Asp-Thr-Ser-Ser-Glu-Ile-Thr-Thr-Lys-Asp-Leu-Lys-Glu-Lys-Lys-Glu-Val-Val-Glu-Glu-Ala-Glu-Asn-OH, written Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN-OH in one-letter code, with a free C-terminal acid. Its molecular formula is C129H215N33O55, its average mass is approximately 3108.3 g/mol, and its CAS registry number is 62304-98-7. The sequence corresponds to the first 28 residues of prothymosin alpha, and the acetyl group on the N-terminal serine is part of the defined structure, not an optional modification: the same 28 residues without the acetyl group are a different compound with a mass about 42 g/mol lower. Our research article What Is Thymosin Alpha-1? Sequence and Identity Reference sets out the registry entries and the analytical consequences of the acetylation.
Two analytical features follow from the composition. The sequence contains no tryptophan, tyrosine or phenylalanine, so it is close to invisible at 280 nm and must be read at 214 nm. And with six glutamates, three aspartates and a free C-terminal acid against four lysines, it is strongly acidic and retains weakly on C18 under a standard trifluoroacetic acid gradient, eluting earlier than its size might suggest. Both points matter when you read a supplier’s chromatogram.
What to look for on any Thymosin Alpha-1 listing
- The acetyl group is stated. A listing that gives 28 residues without “Ac-” or “N-acetyl” has either omitted it or is describing the unacetylated analog. The stated mass settles it: approximately 3108 with the acetyl group, approximately 3066 without.
- The CAS number is 62304-98-7. A different number, or none, is a reason to ask.
- The purity method names a wavelength. For this sequence only 214 nm, or a nearby low-UV wavelength, gives a meaningful area-percent figure.
- The analyst is named as independent or in-house. A chromatogram the seller ran on its own material is not the same evidence as one from a laboratory with no stake in the sale.
- The vial size is stated in milligrams and the price is per vial. Thymosin Alpha-1 is sold in several fills across the market; compare per milligram only after you have confirmed the sequence and the testing claim, because a cheaper milligram of an unconfirmed material is not a saving.
- Ships-from, tracking, free-shipping line and payment routes are stated on the page rather than discovered at checkout.
Our Thymosin Alpha-1 5mg
| Row on the product page | Stated value |
|---|---|
| Sequence | Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN-OH, 28 residues, N-acetylated, free C-terminal acid |
| Molecular formula | C129H215N33O55 |
| Average mass | approx. 3108.3 g/mol |
| CAS number | 62304-98-7 |
| Amount per vial | 5 mg, lyophilized powder, sealed vial |
| HPLC purity | 98 percent or higher by area |
| Shelf life | 36 months in the sealed vial |
The analysis behind the purity row is reverse-phase HPLC performed by an independent laboratory. We do not run it ourselves, and we do not claim mass spectrometry, endotoxin or sterility testing; nothing we sell is represented as sterile. Our vials carry no lot number. The crimp color and cap color identify the result on file for the vials they were applied to, and we send that result on request against the product name and the colors, before or after an order. The method and its limits, including why an area-percent figure is not a measure of net peptide content, are explained on how we test research peptides. The Thymosin Alpha-1 5mg product page carries the full table with identity references.
Price per vial and by quantity
Thymosin Alpha-1 5mg is listed at $60.00 per vial. The bulk tiers are applied automatically to the number of vials of this product in the cart and need no code.
| Vials | Per vial | Note |
|---|---|---|
| 1 | $60.00 | Below the free-shipping line; standard rate charged |
| 2 to 4 | $57.00 | 5 percent off; two vials clear $100 and ship free |
| 5 to 9 | $51.00 | 15 percent off |
| 10 or more | $48.00 | 20 percent off, applied automatically |
A discount code entered at checkout turns bulk pricing off for that order, so the two are never added together. Prices were read from the live catalog on 14 November 2026; the product page shows the current figure.
US shipping, payment and institutional ordering
We ship only within the United States, from inside the United States, so there is no customs stage. Every parcel is tracked and the number is emailed at dispatch, which follows within 1 to 2 business days of payment. Standard delivery typically takes 3 to 7 business days, expedited 1 to 3. Standard shipping is free when the subtotal, after any discount, exceeds $100.
Checkout accepts credit cards and offers “Pay after check out”, under which the order is placed with its prices locked and then settled by Zelle, Apple Cash, Venmo, bank wire, cryptocurrency or a mailed check, quoting the order number. Purchase orders in an institution’s name are accepted. We sell to research institutions, licensed researchers, universities and laboratory R&D purchasers and not to consumers. Sales are final except as our Refund Policy provides for transit damage reported within 48 hours, parcels confirmed lost and products that fail an independent purity test commissioned by the buyer; the shipping and payments FAQ gives the procedure for each.
If you are also looking at TB-500
Buyers sometimes take Thymosin Alpha-1 and TB-500 for variants of one compound because both carry the word thymosin. They are unrelated sequences. TB-500 is a fragment of thymosin beta-4, a different protein, and the two have different lengths, formulas and masses. Each is specified separately on its own product page, and the checks above apply to either. Thymosin Alpha-1 is listed in our Antimicrobial and Cytokine-Pathway Peptides category together with ARA-290 and LL-37, each with sequence, formula and mass on the page.
All products are sold for laboratory research use only and are not for human or animal use. Nothing on this page is preparation, handling or dosing guidance.