Best Place to Buy Thymosin Alpha-1 in 2026

Short answer: Amino Club (Bureau Score 4.8), the Bureau's first choice for Thymosin Alpha-1. Below is why, the three alternatives worth knowing, and what to check before any order. Thymosin Alpha-1 is sold by these stores for laboratory research use only, not for human use. It is also known as thymalfasin.

What to know before buying Thymosin Alpha-1

Thymosin alpha-1 is a 28 amino acid peptide first isolated from the thymus, acetylated at its N-terminal serine (sequence Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN); its synthetic form is called thymalfasin and is sold abroad as Zadaxin. It is studied as an immune modulator, in hepatitis B and C, immune deficiency, sepsis, vaccine response and as an add-on in some cancers.

Thymalfasin is approved in more than 35 countries for hepatitis B and C and as an immune enhancer, but the FDA has not approved it (no thymalfasin product in Drugs@FDA, checked 1 Nov 2026). FDA's compounding safety page (current as of 22 April 2026) lists it among peptides once placed in category 2 and later withdrawn by their nominators, citing a significant risk of immunogenicity and safety information it calls inadequate, and it was not among the seven peptides FDA's advisory committee reviewed in July 2026.

• What to match on the certificate: Match the identity line to C129H215N33O55, average molecular weight 3108.3 (monoisotopic 3106.50), with the mass spec result showing the N-terminal acetyl group, since an unacetylated 28-mer weighs about 42 less. Look for HPLC purity and a mass spec identity result on the same lot number as the vial.
• Vial sizes: Research stores sell it as 5 mg and 10 mg vials; do not confuse it with thymosin beta-4 or TB-500, which are different peptides with different sequences sold under a similar name.
• What it costs: 7 stores the Bureau reviews list Thymosin Alpha-1; on 1 November 2026 the in-stock list prices ran from $4.00 per mg (Amino Club, 10 mg vial) to $12.00 per mg (Amino USA, 5 mg vial), before any code.
• Storage: Suppliers generally state that a lyophilized peptide keeps best sealed and frozen (around -20 C), and that once reconstituted it should be refrigerated and used within a short window or split into aliquots and frozen, avoiding repeated freeze and thaw.

The alternatives

Each one stocks Thymosin Alpha-1 and has been through the Bureau's vendor review. Listed in the Bureau's own vendor order, not by price.

Side by side

Prices are list prices for single vials, read from each store by the Bureau's Vendor Watch on 1 November 2026, before any code. Prices change daily.

How the Bureau picks

The pick is the vendor at the top of the Bureau's vendor list that stocks Thymosin Alpha-1. Scores come from the scorecard, which weighs lab documentation, consistency, shipping and price, and a vendor cannot buy a score. Before any order, match the lot number on the vial to a certificate from a named third-party lab. More in the vendor scorecard and the Thymosin Alpha-1 guide.

Where-to-buy guides for other compounds, built the same way: 5-Amino-1MQ, AOD-9604, ARA-290, BPC-157, CJC-1295 and Ipamorelin, Cagrilintide, DSIP, Epitalon, GHK-Cu, GHRP-6, IGF-1 LR3, Ipamorelin, KPV, Kisspeptin, LL-37, MOTS-c, Melanotan 2, NAD+, PT-141 (Bremelanotide), Pinealon, SS-31, Selank, Semaglutide, Semax, Sermorelin, TB-500, Tesamorelin, VIP.

Frequently asked questions

Where is the best place to buy Thymosin Alpha-1?

The Bureau pick is Amino Club (Bureau Score 4.8). Batch COA on every product page from an 8-assay panel at an ISO 17025 lab. Alternatives that stock it: Ascension Peptides, NextgenPeps, Limitless Biotech.

Is there a discount code for Thymosin Alpha-1?

Reader deals checked by the Bureau: Amino Club, Code 100: 20% off; Ascension Peptides, Our link: 50% off every order; NextgenPeps, Code PEPTIDEBUREAU: 10% off.

How do I check a Thymosin Alpha-1 vendor before ordering?

Match the batch or lot number on the vial to a certificate from a named third-party lab, check the test date, and look for identity (mass spec) as well as purity (HPLC). The Bureau's scorecard records which vendors do this.

Is thymosin alpha-1 FDA approved?

No. The FDA has not approved thymalfasin (there is no thymalfasin product in Drugs@FDA), although it is approved as Zadaxin in more than 35 other countries for hepatitis B and C and as an immune enhancer. In the US it is sold by research vendors for laboratory research use only.

Is thymosin alpha-1 the same as TB-500?

No. Thymosin alpha-1 is a 28 amino acid peptide from the thymus, while TB-500 is sold as a fragment of thymosin beta-4 (FDA lists it as thymosin beta-4 fragment, LKKTETQ). They share the word thymosin but have different sequences and are studied for different things.

Sources

• Dominari et al., Thymosin alpha 1: A comprehensive review of the literature, World J Virol 2020 (PMID 33362999), read 1 November 2026
• PubChem compound 16130571 (thymalfasin): formula, weights, synonyms, read 1 November 2026
• openFDA Drugs@FDA search for thymalfasin, read 1 November 2026
• FDA, Certain bulk drug substances for use in compounding that may present significant safety risks (content current as of 22 Apr 2026), read 1 November 2026
• Foley, FDA to Consider Lifting Restrictions on Numerous Compounded Peptides (5 May 2026; the seven peptides on the 23 to 24 July 2026 PCAC agenda), read 1 November 2026

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