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Specimen Atlas of Research Peptides30 plates · MIT
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XXIXPlate XXIXReviewed 2026-04-25

Thymosin α-1

Synthetic 28-AA thymic peptide

also known as Tα-1, Zadaxin, Thymalfasin, thymosin alpha 1

Synthetic 28-amino-acid peptide identical to a peptide isolated from calf thymus. Approved as Zadaxin (thymalfasin) in 35+ countries for chronic hepatitis B + C, immune restoration after chemotherapy, and as an HIV/HBV vaccine adjuvant. Not FDA-approved in the US, but extensive Phase 3 data exists.

§ I

At a glance

Per dose
1.6 mg
[iyer-2007-talpha1]
Evidence level
Phase 3
[iyer-2007-talpha1][camerini-2001-talpha1]
Half-life
~2 hr
Route

SQ · 2× weekly · 6+ months for chronic indications

§ II

Mechanism

Primary target — Toll-like receptor 9 (TLR9) + T-cell maturation pathway [camerini-2001-talpha1].

Pathway — TLR9 activation → ↑ IFN-α + IL-2 + IFN-γ → enhanced T-cell function + dendritic cell maturation [iyer-2007-talpha1].

Downstream effect — Restored T-cell function, improved viral clearance, anti-tumour adjuvant effects [iyer-2007-talpha1].

Origin — Synthetic 28-AA peptide identical to natural Tα-1 isolated from thymus extract [camerini-2001-talpha1].

§ III

Dosage

Protocols described in the cited literature; not medical advice.

ParameterValue
Standard dose (HBV/HCV)1.6 mg SQ 2× weekly × 6–12 months [iyer-2007-talpha1]
Frequency2× weekly (Mon/Thu typical)
Lower / starter dose0.8 mg per injection
Evidence basisPhase 3 + approved (35+ countries as Zadaxin) [iyer-2007-talpha1]
Duration6–12 months for chronic indications
ReconstitutionSterile water for injection per vial label
TimingNo specific time
Half-life~2 hours plasma; tissue effect days
§ III · b

Reconstitution

A pure mass-to-volume utility. Enter what you have in the vial; the atlas computes the volume per dose. No prescription information.

Inputs
The calculator does pure mass-to-volume math. It does not recommend a dose. Refer to Thymosin α-1's cited literature for protocol specifics.
Volumetric outputFig. C — reconstitution math
Volume per dose
0.313mL
≈ 31.3 units on a U-100 insulin syringe
Concentration
800
mcg per mL
Doses per vial
6
at this dose
§ V

Adverse events

Severities follow the FDA / CTCAE convention.

Injection site reactionmild
Erythema, mild discomfort
GI symptomsmild
Rare nausea
Fatiguemild
Common during initial weeks
Fever / flu-likemild
Mild interferon-like response possible
Autoimmunemoderate
Theoretical risk; caution in active autoimmune disease
Cancer riskmild
No signal — used as adjuvant in oncology
Pregnancy / OBsevere
Avoid
Absolute contraindications
  • — Pregnancy / breastfeeding
  • — Hypersensitivity to peptide
  • — Concurrent immunosuppressant therapy (transplant patients)
Relative contraindications
  • — Active autoimmune disease
  • — Severe immunocompromised state without supervision
§ VI

Administration

  1. 01
    Reconstitution

    Add 1 mL sterile water per 1.6 mg vial → 1.6 mg/mL.

  2. 02
    Injection site

    SQ — abdomen, thigh, or upper arm. Rotate sites.

  3. 03
    Timing

    2× weekly, e.g. Monday + Thursday.

  4. 04
    Storage

    Lyophilised: refrigerate. Reconstituted: refrigerate, use within 24 h.

  5. 05
    Needle

    27–31G, 4–8 mm insulin syringe.

Appendix

Sources

21%

of 39 rendered claims carry a resolvable citation.

  1. [camerini-2001-talpha1]
    Camerini 2001 — Thymosin alpha-1: a clinical update
    Curr Opin Investig Drugs, 2001
    Source →
  2. [iyer-2007-talpha1]
    Iyer 2007 — Zadaxin (Thymalfasin) for chronic hepatitis B and C
    Curr Pharm Des, 2007
    Source →
Plate composed 2026-04-25 · maturity reviewed · schema v1 · Contributors: peptidesdb-core · 31 fields uncited — open contributions
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