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    Thymosin Alpha 1 Peptide: A Provider's Guide to Identity, Vial Format, and Access

    Short answer: Thymosin alpha 1 (Tα1; nonproprietary name thymalfasin) is a 28-amino-acid, N-terminally acetylated peptide first isolated from calf thymus tissue and sequenced by Goldstein and colleagues in 1977 (Goldstein et al., 1977). PubChem lists it as CID 16130571, molecular formula C129H215N33O55, molecular weight ≈3108.3 g/mol, CAS 62304-98-7 (PubChem). For clinics, the thymosin alpha 1 peptide comes as a lyophilized powder in a sealed vial. Biomed Peptides lists THYMOSIN ALPHA-1 in a 10 mg vial for verified, licensed providers only.

    This guide covers what the compound is, where it appears on FDA's compounding pages, how it's supplied and stored, and how provider access works. Clinical decisions stay with the prescribing clinician.

    What is the thymosin alpha 1 peptide?

    Origin and name

    The "thymosins" were named after the thymus, the tissue they were first extracted from. In the 1977 paper, the group isolated thymosin alpha 1 from a calf thymus preparation called thymosin fraction 5. They described it as "a heat stable, highly acidic molecule composed of 28 amino acid residues" and proposed a naming system for the polypeptides in that fraction (Goldstein et al., 1977).

    Pharmacy and regulatory documents often use thymalfasin, the USAN/INN name. PubChem treats thymalfasin, thymosin alpha 1, thymosin α1, and Tα1 as synonyms (PubChem). FDA's compounding pages use "Thymosin-alpha 1 (Ta1)" (FDA).

    Sequence and structure

    From the full chemical name in the PubChem record, the one-letter sequence is (N-terminal acetyl group shown as Ac-):

    Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN

    Attribute Value
    Nonproprietary name Thymalfasin
    Common names Thymosin alpha 1, thymosin α1, Tα1
    Length 28 amino acids, N-terminal acetylation
    Molecular formula C129H215N33O55
    Molecular weight ≈3108.3 g/mol
    CAS (as listed in PubChem) 62304-98-7
    PubChem CID 16130571

    The sequence contains many glutamic acid (E) and aspartic acid (D) residues, which is why the original paper called it "highly acidic." Tα1 can be made by chemical synthesis. Felix and colleagues published a fragment-condensation synthesis in 1985 (Felix et al., 1985).

    These identity values are what you check on a certificate of analysis (COA). The mass spectrometry result should match the ≈3108 Da expected mass, and the sequence should match the 28 residues above, including the acetylated N-terminus.

    Regulatory context: FDA's 503A nomination pages

    Section 503A sets the rules for which bulk drug substances pharmacists and physicians may compound with. A substance generally has to have a USP or NF monograph, be a component of an FDA-approved drug, or appear on FDA's 503A bulks list. FDA also requires a valid COA and an FDA-registered (section 510) manufacturing establishment (FDA).

    Here's what FDA's own pages currently show for thymosin alpha 1:

    • FDA's page on bulk drug substances that may present significant safety risks lists Thymosin-alpha 1 (Ta1) under "Bulk drug substances nominated but withdrawn." FDA describes these as substances "previously in category 2 of the interim policies" whose nominations "were withdrawn by the nominators." The page also summarizes the concerns FDA identified at the time, and providers should read it directly. The content is marked current as of April 22, 2026 (FDA).
    • FDA's list of substances nominated under 503A (updated May 14, 2026) does not name thymosin alpha 1 in category 1, 2, or 3 (FDA nominations list).

    These pages change often. Confirm current status with your compounding pharmacy before you make any formulary decision. For background, see what a 503A pharmacy is.

    How thymosin alpha 1 is supplied to clinics

    Lyophilized vial format

    Thymosin alpha 1 ships as a lyophilized (freeze-dried) powder in a sealed vial. Manufacturer guidance says peptides shouldn't be stored in solution long term because they "may slowly undergo chemical degradation." For longer storage, it recommends keeping them as a lyophilizate in a tightly closed container (Bachem). Our lyophilized peptides guide explains the format and the clinic reconstitution workflow.

    Thymosin alpha 1 5mg vs. 10 mg vials

    People search "thymosin alpha 1 5mg" because 5 mg is a common vial strength across the market. Vial strength is the amount of peptide in the sealed vial. It doesn't change the molecule. The Biomed Peptides lyophilized catalog currently lists THYMOSIN ALPHA-1 as a 10 mg vial. If your practice orders by a different strength, ask our team before you order, and make sure the vial label, the COA, and your records all show the same strength.

    Storage on receipt

    • Keep vials sealed, dry, and protected from light. Follow the product label first.
    • For long-term holding, Bachem recommends storing peptide lyophilizates below −15 °C, with lower temperatures preferred. Refrigeration at 4 °C is acceptable for short-term use (Bachem).
    • Peptides are hygroscopic. Let a cold vial reach room temperature before you open it, so moisture doesn't condense on the powder (Bachem).
    • Bachem notes that peptides containing Asn, Gln, Met, Cys, and/or Trp have limited shelf lives. Tα1 ends in asparagine (N), which is one more reason to follow the labeled expiration and storage conditions.

    Our lyophilized peptides storage guide covers each step in detail. For the diluent, see bacteriostatic water for peptides.

    Documentation to request

    Ask for these with every thymosin alpha 1 lot:

    • Lot-specific COA with an identity result (typically mass spectrometry matching ≈3108 Da), HPLC purity, and peptide content where reported
    • Endotoxin results where applicable
    • Manufacturer and site information, since 503A requires a section 510-registered establishment for bulk drug substances (FDA)
    • Labeled storage conditions and expiration

    Our peptide COA and third-party testing guide explains how to read each section of a COA and match it to the vial in hand.

    Thymosin alpha 1 price and where to buy: provider access

    A lot of the results for "thymosin alpha 1 price" and "thymosin alpha 1 where to buy" are consumer storefronts. Biomed Peptides works differently. We supply physician-use product only to licensed healthcare providers, and we don't sell to patients or consumers.

    What affects provider pricing, in general terms:

    • Vial strength. More peptide per vial costs more per vial.
    • Documentation depth. Lot-specific identity, purity, and endotoxin testing all add cost.
    • Order profile. Office-use stock and patient-specific fulfillment are priced differently.

    Wholesale pricing is visible only to approved accounts. How access works:

    1. Submit the provider application.
    2. Our team verifies your credentials, usually within 24–48 hours.
    3. Approved accounts can view pricing, the full lyophilized catalog, and lot documentation.
    4. Order for office use or patient-specific fulfillment, with shipping to all 50 states.

    Source thymosin alpha 1 for your practice

    Licensed practices and med spas can apply for provider access to view THYMOSIN ALPHA-1 pricing and COAs, or browse the lyophilized catalog to plan their formulary.

    FAQ

    What is the thymosin alpha 1 peptide?

    Thymosin alpha 1 (thymalfasin) is a 28-amino-acid, N-terminally acetylated peptide first isolated from calf thymus and sequenced in 1977. PubChem lists its molecular weight as about 3108.3 g/mol (CID 16130571).

    Is thymalfasin the same as thymosin alpha 1?

    Yes. Thymalfasin is the nonproprietary (USAN/INN) name for thymosin alpha 1. PubChem lists them as synonyms.

    What is thymosin alpha 1's status on FDA's 503A pages?

    FDA's significant-safety-risks page (current as of April 22, 2026) lists Thymosin-alpha 1 (Ta1) among substances previously in category 2 whose nominations were withdrawn. FDA's May 14, 2026 nominations list does not name it in categories 1–3. Confirm current status with your compounding pharmacy.

    Does Biomed Peptides carry thymosin alpha 1 5mg?

    The catalog currently lists THYMOSIN ALPHA-1 as a 10 mg lyophilized vial. Contact our team about other strengths.

    Where can a practice buy thymosin alpha 1?

    From a provider-only supplier that verifies licensure. Biomed Peptides supplies THYMOSIN ALPHA-1 to approved providers. Apply at /apply to see pricing and documentation.

    Sources

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