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Specimen Atlas of Research Peptides30 plates · MIT
Side-by-side · Research reference

ThymalinvsThymosin α-1

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

AHuman-MechanisticDraft12/40 cited
BPhase 3Reviewed8/39 cited
Thymalin
Immune restorer · Russian peptide bioregulator
5–10 mgPer cycle doseKhavinson 2002
HumanMechanisticKhavinson 2002
HoursHalf-life (est)
IM · Daily for 5–10 days · 1-2×/year
Thymosin α-1
Immune modulator · Approved (some countries)
1.6 mgPer doseIyer 2007
Phase 3Evidence levelIyer 2007Camerini 2001
~2 hrHalf-life
SQ · 2× weekly · 6+ months for chronic indications

01Mechanism of Action

Parameter
Thymalin
Thymosin α-1
Primary target
T-cell precursors + thymus-axis maturation pathwayKhavinson 2002
Toll-like receptor 9 (TLR9) + T-cell maturation pathwayCamerini 2001
Pathway
Modulation of T-cell differentiation + thymic hormone restoration in age-involuted thymusKhavinson 2002
TLR9 activation → ↑ IFN-α + IL-2 + IFN-γ → enhanced T-cell function + dendritic cell maturationIyer 2007
Downstream effect
Restored T-cell populations, improved immune surveillance, reduced infection rates in elderlyKhavinson 2002
Restored T-cell function, improved viral clearance, anti-tumour adjuvant effectsIyer 2007
Feedback intact?
Origin
Polypeptide fraction isolated from calf thymus extractKhavinson 2002
Synthetic 28-AA peptide identical to natural Tα-1 isolated from thymus extractCamerini 2001
Antibody development

02Dosage Protocols

Parameter
Thymalin
Thymosin α-1
Standard dose
5–10 mg / day IM × 5–10 daysKhavinson 2002
Frequency
Once daily during cycle
2× weekly (Mon/Thu typical)
Lower / starter dose
2.5 mg / day
0.8 mg per injection
Evidence basis
Russian clinical + in vitroKhavinson 2002
Phase 3 + approved (35+ countries as Zadaxin)Iyer 2007
Duration
5–10 day cycles, 1–2× per year
6–12 months for chronic indications
Reconstitution
Saline or bacteriostatic water
Sterile water for injection per vial label
Timing
Morning preferred
No specific time
Half-life
Hours (estimated)
~2 hours plasma; tissue effect days
Standard dose (HBV/HCV)
1.6 mg SQ 2× weekly × 6–12 monthsIyer 2007

04Side Effects & Safety

Parameter
Thymalin
Thymosin α-1
Injection site reaction
Mild erythema at IM site
Erythema, mild discomfort
Allergic reaction
Rare hypersensitivity to bovine-derived polypeptide
Autoimmune flare
Theoretical risk in active autoimmune disease
Long-term safety
Limited Western data
Pregnancy / OB
Avoid
Avoid
GI symptoms
Rare nausea
Fatigue
Common during initial weeks
Fever / flu-like
Mild interferon-like response possible
Autoimmune
Theoretical risk; caution in active autoimmune disease
Cancer risk
No signal — used as adjuvant in oncology
Absolute Contraindications
Thymalin
  • ·Pregnancy / breastfeeding
  • ·Bovine protein hypersensitivity
Thymosin α-1
  • ·Pregnancy / breastfeeding
  • ·Hypersensitivity to peptide
  • ·Concurrent immunosuppressant therapy (transplant patients)
Relative Contraindications
Thymalin
  • ·Active autoimmune disease
  • ·Concurrent immunosuppressant therapy
Thymosin α-1
  • ·Active autoimmune disease
  • ·Severe immunocompromised state without supervision

05Administration Protocol

Parameter
Thymalin
Thymosin α-1
1. Reconstitution
Add 1–2 mL saline or bacteriostatic water per 10 mg vial.
Add 1 mL sterile water per 1.6 mg vial → 1.6 mg/mL.
2. Injection site
Intramuscular — deltoid or gluteal. Rotate sites.
SQ — abdomen, thigh, or upper arm. Rotate sites.
3. Timing
Morning preferred during cycle.
2× weekly, e.g. Monday + Thursday.
4. Storage
Lyophilised: refrigerate, light-protected. Reconstituted: use immediately.
Lyophilised: refrigerate. Reconstituted: refrigerate, use within 24 h.
5. Needle
23–25G, 25–38 mm IM needle.
27–31G, 4–8 mm insulin syringe.

06Stack Synergy

Thymalin
+ Thymosin α-1
Moderate
View Thymosin α-1

Thymalin is a polypeptide complex; Thymosin α-1 is a single purified peptide. Both target the thymus-axis but at different levels — Thymalin restores broad thymic signaling; Tα-1 provides a specific molecular activator. Anecdotally combined for elderly immune support.

Thymalin
5–10 mg IM · daily × 7 days
Thymosin α-1
1.6 mg SQ · 2× weekly during the cycle
Primary benefit
Broad thymic restoration + targeted immune activation
Thymosin α-1
— no documented stacks