Thymalin vs HD5

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

Research Score

PropertyThymalinHD5
CategoryImmune SupportImmune Support
Full NameCalf Thymus Peptide Fraction (Thymalin)Human Alpha-Defensin 5
Molecular WeightN/A3708 Da
Half-LifeN/AMinutes to hours; protease-sensitive
Amino AcidsN/A32
Typical Dose5-20 mgResearch use only; no approved human dose
RouteIntramuscularOral-local gut / Research parenteral
Purity≥98%≥98%
Studies Count120260
Research StatusClinicalPre-clinical

Thymalin Benefits

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

HD5 Benefits

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

Thymalin Dosing

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

HD5 Dosing

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

Thymalin Side Effects

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

HD5 Side Effects

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

Research Overview

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.

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.

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Common Stacking Partners

Thymalin stacks with:

Vitamin DZincProbiotics

HD5 stacks with:

probioticsprebioticszinc-carnosine
thymic-peptideimmunomodulatorclinical-literaturealpha-defensingut-immunitymucosal-defensemicrobiome