Where to buy Thymosin Alpha-1 (also sold as Tα1, Thymalfasin, TA1): the 4 vendors below are the ones we have a dated product-page price for, ranked on documentation first and price second. Nothing here is typed from memory — every number links to a date.
Research use only. Compound Review scores vendors on documentation — laboratory certificates, lot records, pricing and company identity. Nothing on this page is guidance on human or veterinary use, dosing or health outcomes.
Reference size 5mg — the size most of these vendors sell. Other sizes we have on record are listed per vendor.
| # | Vendor | Rubric | 5mg price | Other sizes | Trustpilot | Buy |
|---|---|---|---|---|---|---|
| 1 | PS PeptidesPartner North American Diagnostics | 8/10 | $54.99 ($11.00/mg · 23 Sept 2026 · list price) | — | 4.3 (204 reviews) | HEALTH 10% off |
| 2 | Puratek PeptidesPartner ILS Laboratories (on certificates) · page credits Freedom Diagnostics | 7/10 | not sold at 5mg | 10mg $59.95 | profile removed | Visit |
| 3 | AIO Peptides Freedom Diagnostics | 6/10 | $41.25 ($8.25/mg · 1 Oct 2026 · logged in; list $55.00 struck) | — | profile removed | Visit |
| 4 | Licensed PeptidesPartner Vanguard Laboratory (printed 'Vangaurd' on COA panels) | 5/10 | $61.99 ($12.40/mg · 23 Sept 2026 · list price; 5mg; sold as 'Thymosin Alpha-1 5mg') | — | profile removed | Affiliate5 5% off |
Thymosin alpha-1 (thymalfasin) is a 28-residue peptide that is approved as a prescription product in a number of countries and sold on the research market by fewer vendors than the popular healing peptides. It is longer and more expensive to synthesise than most compounds here, and vial sizes are correspondingly smaller.
It is routinely confused with TB-500, which is a fragment of thymosin beta-4 — a different protein with a different sequence and a different research literature. Catalogs list the two near each other and the names look alike; the certificate's mass-spectrometry identity is what tells them apart.
At least one vendor we read listed it as out of stock at the time. Availability is noted per vendor, and the ordering is by rubric score first because the field is too small for a price ranking to mean much.
What we can verify
Names North American Diagnostics, and the lab's own portal returns the record for test ID NAD-0037963 (BPC-157, lot PSP-09112026BP, 99.97%, 4.88mg on a 5mg label) — looked up 3 Oct 2026. 59 certificates downloadable without an account, sized pricing across the widest GLP range we cover, card checkout (Visa/Mastercard/Amex/Discover, Afterpay, Klarna). The September '5-star from thousands' blog claim is gone, so the clean-record point is now awarded.
Net content: Measured mass vs label published (4.88mg on a 5mg label on NAD-0037963, 97.6%; 5.03mg on PSP-0028020 in Sep)
Where it falls short
Home and about pages claim 'cGMP-certified facilities' and 'accredited laboratories' while the vendor's own legit post says cGMP certificates do not exist, and no accrediting body is named. The ProSupply Services LLC name we read in September is no longer printed anywhere; 'New Jersey-based' only, no address, email-only support. Trustpilot 4.3 is still the low end of the partner set.
What we can verify
Credits Freedom Diagnostics on a certifications page listing dozens of batch-labelled certificate images viewable without login. Legal entity, address and phone published: Puratek LLC, Las Vegas, NV. Cheapest BPC-157 10mg in this batch at $29.95.
Net content: Certificate reports Net Peptide Content 10.7mg (V0) / 10.45mg (V1) vs 10mg label, 99.96% purity (lot BPC10005)
Where it falls short
Trustpilot profile removed for guideline violations (read 5 Sep 2026) — no independent review base. The certificate we opened is an ILS Laboratories report (COA-2026-413074, lot BPC10005, 10.7mg vs 10mg) with an ILS access code — while the certifications page credits Freedom Diagnostics. Purity guarantee is 99% on the homepage and 98.5% on the policy page. TB-500 and GLP products are listed without stated sizes, and the GLP compound identities are not stated.
What we can verify
Read on 1 October 2026 through a registered account (every URL still redirects to a login form logged out). Behind the wall: a COA page listing 38 lots with lot codes, each opening a Freedom Diagnostics certificate; the TB-500 10mg report (lot AIOTB326, accession 2603060239, search code AIOP2603060239, reported 7 Mar 2026) states 10.32 mg net peptide content and 99.884% purity by HPLC-UV with MS, and the lab's own lookup returned 'Document found' with the PDF served from coas.freedomdiagnosticstesting.com. A 68-product catalog with sized pricing (BPC-157 10mg $71 list / $53.25 on the 25% sitewide sale; TB-500 10mg $66 / $49.50).
Net content: Certificate reports Net Peptide Content 10.32 mg on a 10mg label (103%), purity 99.884%, identity Thymosin Beta-4 by HPLC-UV with mass spectrometry
Where it falls short
No legal entity anywhere: the terms page still reads 'governed by the laws of [Jurisdiction]' — a template placeholder — and the only contact is hello@aiopeptides.com and a Texas-area phone number. Trustpilot profile REMOVED. Login wall on every page. All sales final. Zelle or ACH earn an extra 5%; we did not examine the card rail. aiopeptidesusa.com is a lookalike (registered 18 Apr 2026, crypto wallet printed on the product page, no certificates) — AIO's own site names aiopeptides.com as its only domain.
Before you order, check the batch
A ranking tells you which vendors have good practices; it cannot tell you about the specific vial you receive. When your order arrives, compare the batch number on the label to the certificate. If they do not match, or there is no batch number, the documentation does not cover what you were sent, regardless of who you bought from. How to read a peptide COA.
As of 1 Oct 2026, 4 of the 78 vendors on our scoreboard list Thymosin Alpha-1 with a price we have read on the product page: PS Peptides, Puratek Peptides, AIO Peptides, Licensed Peptides. Every one of them is scored on the same 10-point rubric; the table above shows the score, the dated price and what you can verify before ordering.
At the 5mg size, the lowest price we have on record is AIO Peptides at $41.25 (read 1 Oct 2026) — logged in; list $55.00 struck. It scores 6/10 on documentation. Price is the second sort key on this page, not the first, because an underdosed vial at a low price is the most expensive outcome.
PS Peptides leads at 8/10: named laboratory, certificates that resolve on the laboratory's own site, measured milligrams against the label, and a published legal identity. The per-criterion evidence, with dates, is on each vendor's review page.
Thymosin Alpha-1 is sold by these vendors as a research chemical for laboratory use, not for human consumption; none of it is FDA-approved in this form. Legality of purchase varies by jurisdiction and the compound, and it is your responsibility to know your local rules. Our pages assess documentation and pricing; they are not legal or medical advice.
Rubric score first. Among equal scores, the lower verified price per milligram at 5mg. Then the larger independent review base. Affiliate partnership is not an input: 3 of the 4 vendors here are partners and they sit wherever the evidence puts them.
No. Thymosin alpha-1 is a 28-residue peptide from prothymosin alpha; TB-500 is a short fragment of thymosin beta-4. They share the word thymosin and nothing else that matters. Check the certificate's stated molecular weight if the listing is ambiguous.
Length. Synthesis cost and the chance of impurity both rise with the number of residues, and a 28-residue peptide is at the long end of what research vendors stock. Compare per milligram at the same size.