Buy Thymosin alpha-1 for Research: 2 Vendors Compared (Prices, COAs)
Checked, not rated · Updated 3 October 2026
Thymosin alpha-1 is not approved by FDA for human use, and it is sold in the US labelled for research use only. 2 of the 3 vendors I check sell it online (Spartan Peptides and BioEdge Research Labs), from $88 for a 10 mg vial as of 3 October 2026.
FDA says it has approved no drug product containing thymosin alpha-1.
The table compares vendors on FDA record, testing lab, batch COAs and price. Before buying from anyone, run my vendor checklist.
- Class
- Immune-modulating peptide (28 amino acids)
- Background
- Licensed in a number of countries, classically for chronic hepatitis B.
- Human evidence
- Strong human evidence
The evidence, risks and legal detail: my Thymosin alpha-1 guide. Dosing and vial maths: Thymosin alpha-1 dosage.
Thymosin alpha-1 vendors compared
The checklist results come from my review of each vendor and cover the whole store. A vendor can publish COAs for some products and not others. The featured vendor is pinned first; the order is not a ranking.
| Vendor | Product | Price | FDA record | Names its lab | Batch COAs | Card payment | Link |
|---|---|---|---|---|---|---|---|
| Spartan PeptidesFeaturedMy Spartan Peptides review | 5 mg vial | $99.00as of 3 October 2026 | No warning letter found | Yes | Not verified | Not verified | View product → |
| BioEdge Research LabsMy BioEdge Research Labs review | 10 mg vial | $88.00as of 3 October 2026 | No warning letter found | Yes | Yes | Not verified | View product → |
Prices are for the product named, as shown on the vendor's own product page on the date given. They change often. Checklist results were verified on 3 October 2026. All vendors and how they compare.
What a Thymosin alpha-1 COA should show
A certificate of analysis (COA) is the lab report for one batch. For thymosin alpha-1, check these:
- Identity by mass spectrometry, with the expected and the measured mass side by side. For thymosin alpha-1, expect about 3,108.3 Da (C129H215N33O55); the sequence is 28 amino acids, SDAAVDTSSEITTKDLKEKKEVVEEAEN.
- Thymosin alpha-1 (thymalfasin) has an acetylated N-terminus. A COA for thymosin beta-4 or TB-500 is for a different peptide.
- Purity by HPLC for this batch, shown as a chromatogram as well as a percentage.
- A lot number that matches your vial or pack, the test date and the lab's name, so you can confirm the certificate on the lab's own site.
A purity figure does not cover sterility or bacterial endotoxins; a COA covers those only if it reports separate tests for them. Line by line: how to read a peptide COA.
Red flags when buying thymosin alpha-1
- A vial presented as Zadaxin. Zadaxin is SciClone's licensed product abroad, and a research vial is not it.
- No certificate of analysis for the batch you will receive, or one without a lot number or a named lab.
- Dosing instructions or treatment claims for people on the product page.
- An FDA warning letter naming the seller. Search fda.gov before you pay.
- No way to pay with buyer protection, such as a credit card.
Common questions
Where can I buy thymosin alpha-1?
Online, from research vendors that label it for laboratory use only. I list 2 checked vendors: Spartan Peptides and BioEdge Research Labs, from $88 for a 10 mg vial as of 3 October 2026. Before you pay, confirm the batch COA on the testing lab's own site.
Is thymosin alpha-1 for sale legally?
Thymosin alpha-1 is sold in the US labelled for laboratory research use only. It is not approved by FDA for human use, and it cannot lawfully be marketed as a supplement or a medicine. This is general information, not legal advice.
Do I need a prescription for thymosin alpha-1?
No US-approved thymosin alpha-1 product exists for a doctor to prescribe. Research vendors sell it without a prescription, labelled for laboratory use only. It is sold in some other countries as Zadaxin (SciClone Pharmaceuticals), classically for chronic hepatitis B. FDA says it is not approved in Japan or in Europe, except Italy.
How much does thymosin alpha-1 cost?
On the vendors' own product pages: Spartan Peptides, 5 mg vial, $99.00 (as of 3 October 2026); BioEdge Research Labs, 10 mg vial, $88.00 (as of 3 October 2026). Prices change often, so check the product page before you rely on one.
How do I know if thymosin alpha-1 is real?
Only a lab test can tell you. Ask for the certificate of analysis (COA) for your batch, and confirm it on the testing lab's own site. The mass spectrometry result should match the expected mass of thymosin alpha-1, about 3,108.3 daltons (C129H215N33O55). A vendor's COAs for other products say nothing about this one, so check that the certificate names thymosin alpha-1 and your lot number.
Who sells the best thymosin alpha-1?
I don't rank vendors, so I don't name a best one. Compare what each lets you check: a named testing lab, a COA for your lot that the lab confirms on its own site, and no FDA warning letter. The table shows my checklist result for each vendor. A vendor that passes every check can still ship a bad batch.
Sources
- Vendor checks: my review of each vendor, on the date shown under the table. Products and prices: each vendor's own product page.
- Legal status, class and evidence: my Thymosin alpha-1 guide, which cites its sources. Formula, mass and sequence: the structure record shown on that guide, checked against two sources.