HD5 vs Thymalin

Head-to-head comparison of HD5 (Human Alpha-Defensin 5) and Thymalin (Calf Thymus Peptide Fraction (Thymalin)) — benefits, dosing, side effects, research data, and where to buy.

Research Score

PropertyHD5Thymalin
CategoryImmune SupportImmune Support
Full NameHuman Alpha-Defensin 5Calf Thymus Peptide Fraction (Thymalin)
Molecular Weight3708 DaN/A
Half-LifeMinutes to hours; protease-sensitiveN/A
Amino Acids32N/A
Typical DoseResearch use only; no approved human dose5-20 mg
RouteOral-local gut / Research parenteralIntramuscular
Purity≥98%≥98%
Studies Count260120
Research StatusPre-clinicalClinical

HD5 Benefits

  • gut mucosal defense
  • antimicrobial activity
  • microbiome balance support
  • barrier integrity support

Thymalin Benefits

  • t-cell support
  • leukocyte recovery
  • immunomodulation
  • infection-resilience

HD5 Dosing

0.1–10 µM in vitro|1–5 mg/kg in animal models|No established human dose

Thymalin Dosing

5-10 mg IM daily|3-10 day cycles|repeat cycles after 1-4 weeks if studied

HD5 Side Effects

  • protease sensitivity
  • potential epithelial irritation at high concentrations
  • unknown systemic safety

Thymalin Side Effects

  • injection-site discomfort
  • transient fever
  • rash/allergy

Research Overview

HD5

HD5 has been widely studied in intestinal innate immunity, particularly for its role in defending crypts against bacterial invasion. Preclinical literature supports activity against multiple microbes and links altered HD5 biology with gut barrier dysfunction.

Thymalin

Thymalin appears in Soviet/Russian clinical literature as a thymus peptide complex used to normalize immune parameters after illness, surgery, or radiation exposure. Reports commonly focus on changes in lymphocyte subsets, phagocytic activity, and infection frequency rather than a single isolated peptide mechanism.

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Common Stacking Partners

HD5 stacks with:

probioticsprebioticszinc-carnosine

Thymalin stacks with:

Vitamin DZincProbiotics
alpha-defensingut-immunitymucosal-defensemicrobiomethymic-peptideimmunomodulatorclinical-literature