Peptide Comparison
Thymulin (FTS)vsThymosin Alpha-1
Zinc-dependent thymic hormone for immune restoration and T cell maturation
Your immune system's master trainer—a naturally occurring thymus peptide that wakes up tired immune cells, helps your body fight infections, and keeps your defenses sharp as you age.
At a Glance
Quick
comparison
Dose Range
Thymulin (FTS)
100–500 mcg
Thymosin Alpha-1
1.6–3.2 mg
Frequency
Thymulin (FTS)
Once daily
Thymosin Alpha-1
Twice weekly
Administration
Thymulin (FTS)
Subcutaneous injection
Thymosin Alpha-1
Subcutaneous injection
Cycle Length
Thymulin (FTS)
4-6 weeks
Thymosin Alpha-1
8-12 weeks
Onset Speed
Thymulin (FTS)
Moderate (1-2 weeks)
Thymosin Alpha-1
Moderate (1-2 weeks)
Evidence Level
Thymulin (FTS)
Limited human trials
Thymosin Alpha-1
Moderate human trials (Phase 1-2)
Efficacy
Benefit
ratings
Immune Restoration
Anti-Inflammatory
Age-Related Immune Decline
Immune Activation
Infection Fighting
Immune Balance
Technical Data
Compound
specifications
Thymulin (FTS)
Molecular Formula
C33H54N12O15
Molecular Weight
858.9 g/mol
Half-Life
Approximately 2 hours
Bioavailability
Low oral bioavailability (injected administration required)
CAS Number
63958-90-7
Thymosin Alpha-1
Molecular Formula
C129H215N33O55
Molecular Weight
3108.32 g/mol
Half-Life
Approximately 2 hours
Bioavailability
High when injected subcutaneously (rapid absorption, peak at ~2 hours)
CAS Number
62304-98-7
Protocols
Dosing
tiers
Thymulin (FTS)
Thymosin Alpha-1
Applications
Best
suited for
Thymulin (FTS)
Age-Related Immune Decline
Thymulin levels naturally drop significantly in elderly populations. Supplementation can restore T cell maturation and immune responsiveness in aging. Research shows thymulin can reverse age-related thymic involution and restore helper/suppressor T cell balance.
Recovery from Severe Malnutrition
In severely malnourished individuals, the thymus shrinks and T cell development is impaired. In vitro studies show thymulin can restore T cell maturation even in those with thymic involution, making it useful in recovery protocols.
Chronic Inflammatory Conditions
Thymulin inhibits NF-κB activation and suppresses pro-inflammatory cytokines (IL-6, TNF-α, IL-8). Animal models show effectiveness in lung diseases, inflammatory pain, and neuroinflammation. Anti-inflammatory effects work through p38 MAPK suppression.
Thymosin Alpha-1
Chronic Hepatitis B or C Support
Thymosin Alpha-1 has its strongest clinical evidence here. Multiple trials show it helps clear viral loads and normalize liver enzymes, especially when combined with antiviral medications. It's approved in over 30 countries specifically for hepatitis treatment.
Cancer Treatment Support
When used alongside chemotherapy, Thymosin Alpha-1 may help maintain immune function that chemo tends to suppress. Research in lung cancer, melanoma, and liver cancer shows improved outcomes when added to standard treatments. It helps your immune system keep fighting even during tough treatments.
Age-Related Immune Decline
As you age, your thymus shrinks and produces less thymosin naturally—a process called immunosenescence. Supplementing with Thymosin Alpha-1 may help compensate, keeping your immune defenses more youthful and responsive. Think of it as replacing what your body makes less of over time.
Severe Infection Recovery
In sepsis and critical infections, Thymosin Alpha-1 has shown promise for reducing mortality by helping restore immune balance. It's particularly interesting because it modulates immunity rather than just boosting it—calming overreaction while enhancing pathogen-fighting ability.
Safety Profile
Side
effects
Thymulin (FTS)
Common
- Local injection site reactions
- Mild fatigue or lethargy
- Transient headache
Uncommon
- Mild fever or chills
- Sleep disturbance or vivid dreams
- Appetite changes
- Transient lymph node swelling
Serious
- Severe allergic reaction
- Uncontrolled immune activation
Thymosin Alpha-1
Common
- Injection site reactions
- Mild fatigue
- Flu-like symptoms
Uncommon
- Mild fever
- Lymph node awareness
Serious
- Allergic reaction
Research Status
Safety
& evidence
Thymulin (FTS)
Evidence Level
Limited human trials
FDA Status
Research compound
Safety Overview
Thymulin is a naturally occurring thymic hormone with favorable safety profile in research. No reported serious adverse events in animal models even at high doses. Limited human safety data but observed studies suggest good tolerability. Requires concurrent zinc supplementation for biological activity and additional safety assurance. Most concerns relate to immune overactivation in susceptible individuals, not direct peptide toxicity.
Contraindications
- xUncontrolled autoimmune disease
- xSevere zinc deficiency requiring IV repletion
- xThymic tumors or malignancies
- xPregnancy (limited safety data)
Thymosin Alpha-1
Evidence Level
Moderate human trials (Phase 1-2)
FDA Status
FDA approved for other use
Safety Overview
Thymosin Alpha-1 has one of the most extensive safety records of any peptide, with decades of clinical use across multiple countries. Studies consistently report minimal side effects—mostly limited to mild injection site reactions. The 2-hour half-life means it doesn't accumulate in your system. It's been used safely in thousands of patients with hepatitis, cancer, and other serious conditions.
Contraindications
- xOrgan transplant recipients on immunosuppressants
- xActive autoimmune disease flares
- xKnown allergy to thymosin peptides
- xPregnancy or breastfeeding
- xChildren under 18 without medical supervision
Decision Guide
Which is
right for you?
Choose Thymulin (FTS) if...
- Immune system restoration
- T cell maturation in immunocompromised states
- Age-related immune decline
- Chronic inflammatory conditions
Choose Thymosin Alpha-1 if...
- Immune system strengthening
- Chronic infection support
- Cancer adjunct therapy
- Healthy aging immune support