Imunofan vs Thymosin Alpha-1
Synthetic hexapeptide derived from thymopoietin with immunomodulatory, antioxidant, and hepatoprotective properties
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.
Written by Michael Carroll — Owner, Director of Research · Reviewed by the Peptide Initiative Research Team · Editorial standards
Quick comparison
Dose range
Imunofan
45–45 mcg
Thymosin Alpha-1
1.6–1.6 mg
Frequency
Imunofan
Once daily
Thymosin Alpha-1
Twice weekly
Administration
Imunofan
Subcutaneous injection
Thymosin Alpha-1
Subcutaneous injection
Cycle length
Imunofan
8-12 weeks
Thymosin Alpha-1
8-12 weeks
Onset speed
Imunofan
Rapid (hours to days)
Thymosin Alpha-1
Moderate (1-2 weeks)
Evidence level
Imunofan
Limited human trials
Thymosin Alpha-1
Moderate human trials (Phase 1-2)
Benefit ratings
Immune
Healing & Recovery
Anti-Aging
Immune Activation
Infection Fighting
Immune Balance
Compound specifications
Imunofan
Molecular formula
C36H61N13O10
Molecular weight
836.0 g/mol
Half-life
Approximately 2-4 hours (intranasal administration)
Bioavailability
~90-95% (subcutaneous injection)
CAS number
Not assigned (Russian pharmacopeia compound)
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
Dosing compared
Imunofan
Subcutaneous
45 mcg per dose
Once daily or every other day · Course of 5-15 injections (about 10-30 days)
Standard injectable dose per the Russian pharmacopeia product label; the single subcutaneous dose is 45 mcg with a maximum daily dose of 45 mcg. Given in courses depending on the indication [1][5].
Intramuscular
45 mcg per dose
Once daily or every other day · Course of 5-15 injections (about 10-30 days)
Same 45 mcg single dose can be given intramuscularly; identical course structure to the subcutaneous route [1][5].
Intranasal
50 mcg per dose (one spray in each nostril)
Once to twice daily · 8-15 days per course
Intranasal spray delivers 50 mcg per dose; one dose into each nasal passage once daily for 8-10 days, or twice daily for 10-15 days for certain indications [5].
Thymosin Alpha-1
Subcutaneous injection
1.6 mg
Twice weekly (3-4 days apart) · 6-12 months
Established clinical dose for thymalfasin (Zadaxin); body-surface-scaled as 900 mcg/m2 [4][6]. Phase III chronic hepatitis B trials used 1.6 mg SC twice weekly for 6-12 months [4].
1.6 mg daily, then 1.6 mg twice weekly
Daily for an initial loading period, then twice weekly · 12+ weeks
Some immune-adjuvant and acute protocols front-load with daily dosing before settling to the standard twice-weekly schedule [4][6].
Best suited for
Imunofan
Cancer Adjuvant Therapy
Imunofan enhances the body's reserve capacity to inactivate free radicals and oxidants during chemotherapy and radiation, substantially reducing toxic reactions and enabling continuity of cancer treatment. [1] Its unique ability to inhibit multiple drug resistance proteins may also improve chemotherapy drug effectiveness [3].
Chronic Viral Hepatitis
With established hepatoprotective properties and immune-restoring capabilities, Imunofan is used as adjunctive therapy in chronic hepatitis B and C, helping restore antiviral immunity and supporting liver function recovery [1].
Chronic Infections with Immunodepression
Patients with chronic infections (brucellosis, opportunistic infections in HIV) who display cell-mediated immunodepression may benefit from Imunofan's three-phase immune restoration, particularly the sustained slow-phase effect lasting up to 4 months [1][6].
Oxidative Stress Reduction
The rapid antioxidant phase makes Imunofan valuable for conditions involving elevated oxidative stress, as it directly inactivates free radicals and peroxide compounds while restoring the body's oxidative-antioxidant balance [1].
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.
Side effects
Imunofan
Common
- Injection site reaction
- Transient headache
- Nasal irritation (intranasal form)
- Transient mild fever
- Mild fatigue
- Gastrointestinal discomfort (suppository form)
Uncommon
- Allergic reaction
Serious
- Anaphylactic reaction / Severe hypersensitivity
Thymosin Alpha-1
Common
- Injection site reactions
- Mild fatigue
- Flu-like symptoms
Uncommon
- Mild fever
- Lymph node awareness
Serious
- Allergic reaction
Safety & evidence
Imunofan
Evidence level
Limited human trials
FDA status
Research compound
Safety overview
Imunofan (Iletin-alpha, a synthetic tetrapeptide) demonstrates good tolerability in Russian clinical practice spanning 20+ years [7] with oral and parenteral administration. Immunomodulatory peptides carry theoretical risks of over-stimulating autoimmune responses, but Imunofan safety data show no increased autoimmune flare rates in patients with existing autoimmune conditions. Injection site reactions and mild fever (1-3% of users) are the documented adverse events, not immunotoxicity. The mechanism of enhanced T-cell maturation appears selective and safe at therapeutic doses.
Contraindications
- Known hypersensitivity to imunofan or excipients
- Pregnancy complicated by Rh-conflict (contraindicated)
- Children under 2 years of age
- Severe allergic conditions in acute exacerbation
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
- Organ transplant recipients on immunosuppressants
- Active autoimmune disease flares
- Known allergy to thymosin peptides
- Pregnancy or breastfeeding
- Children under 18 without medical supervision
Which is right for you?
Choose Imunofan if...
- Immune system restoration and modulation
- Adjunctive therapy during chemotherapy and radiation
- Support during chronic hepatitis treatment
- Reducing oxidative stress and free radical damage
Choose Thymosin Alpha-1 if...
- Immune system strengthening
- Chronic infection support
- Cancer adjunct therapy
- Healthy aging immune support