Peptide Comparison
GramicidinvsThymosin Alpha-1
Historic 15-amino-acid linear pentadecapeptide antibiotic with alternating D- and L-amino acids — the first commercially produced antibiotic discovered by René Dubos in 1939, forming monovalent cation-selective transmembrane channels in bacterial membranes, FDA-approved as a topical/ophthalmic antimicrobial component of Neosporin and related preparations
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
Gramicidin
0.025–0.25 mg/mL
Thymosin Alpha-1
1.6–3.2 mg
Frequency
Gramicidin
Multiple times daily
Thymosin Alpha-1
Twice weekly
Administration
Gramicidin
Topical application (primary clinical route)
Thymosin Alpha-1
Subcutaneous injection
Cycle Length
Gramicidin
8-12 weeks
Thymosin Alpha-1
8-12 weeks
Onset Speed
Gramicidin
Rapid (hours to days)
Thymosin Alpha-1
Moderate (1-2 weeks)
Evidence Level
Gramicidin
Strong human trials (Phase 3 or FDA approved)
Thymosin Alpha-1
Moderate human trials (Phase 1-2)
Efficacy
Benefit
ratings
Energy
Immune
Immune Activation
Infection Fighting
Immune Balance
Technical Data
Compound
specifications
Gramicidin
Molecular Formula
C₉₉H₁₄₀N₂₀O₁₇ (gramicidin A)
Molecular Weight
1,882.3 Da (gramicidin A); Gramicidin D mixture: ~1,880-1,900 Da average
Half-Life
Local tissue persistence: hours to days at topical application sites (protease-resistant D-amino acid structure); systemic half-life: not applicable (hemolytic — never administered systemically); single channel lifetime: ~1 second (open/close kinetics in electrophysiology)
Bioavailability
Topical: local tissue concentrations at application site; systemic absorption negligible through intact skin and eye; oral bioavailability: not applicable (not used orally for systemic effect; would cause GI hemolysis); intrinsically resistant to proteases due to D-amino acid content
CAS Number
11029-61-1 (gramicidin A); 1405-97-6 (gramicidin D mixture)
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
Gramicidin
Thymosin Alpha-1
Applications
Best
suited for
Gramicidin
Topical treatment of bacterial conjunctivitis and external eye infections (FDA-approved)
Gramicidin is particularly well-suited for individuals focused on topical treatment of bacterial conjunctivitis and external eye infections (fda-approved). Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Prophylaxis and treatment of superficial skin infections, minor cuts, scrapes, and burns (OTC topical preparations)
Gramicidin is particularly well-suited for individuals focused on prophylaxis and treatment of superficial skin infections, minor cuts, scrapes, and burns (otc topical preparations). Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Research into ion channel biophysics, single-channel electrophysiology, and membrane transport mechanisms
Gramicidin is particularly well-suited for individuals focused on research into ion channel biophysics, single-channel electrophysiology, and membrane transport mechanisms. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Combination topical antimicrobial therapy providing Gram-positive coverage alongside polymyxin B for Gram-negatives
Gramicidin is particularly well-suited for individuals focused on combination topical antimicrobial therapy providing gram-positive coverage alongside polymyxin b for gram-negatives. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
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
Gramicidin
Common
- Ophthalmic stinging/burning
- Local skin irritation
- Temporary blurred vision
- Contact sensitization
Uncommon
- Superinfection
Serious
- Hemolytic toxicity with systemic absorption
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
Gramicidin
Evidence Level
Strong human trials (Phase 3 or FDA approved)
FDA Status
FDA approved for this use
Safety Overview
Gramicidin is a cyclic peptide antibiotic derived from Bacillus brevis with a 70+ year track record of topical safety. It functions as a pore-former in bacterial membranes and shows minimal systemic absorption when applied to intact skin or mucous membranes, making it extremely low-toxicity for localized use. The primary safety concern is sensitization reactions in 1-5% of users with prolonged exposure, not organ toxicity. Gramicidin is FDA-approved for topical antibacterial applications and generally well-tolerated across age groups.
Contraindications
- xKnown hypersensitivity to gramicidin or any component of topical/ophthalmic formulations
- xSystemic administration by any route — gramicidin is hemolytic and toxic to red blood cells; strictly topical/ophthalmic use only
- xDeep puncture wounds or severe burns requiring systemic antimicrobial coverage
- xProlonged use on large open wounds — even topical gramicidin may cause hemolysis if absorbed systemically through extensive denuded skin
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 Gramicidin if...
- Topical treatment of bacterial conjunctivitis and external eye infections (FDA-approved)
- Prophylaxis and treatment of superficial skin infections, minor cuts, scrapes, and burns (OTC topical preparations)
- Research into ion channel biophysics, single-channel electrophysiology, and membrane transport mechanisms
- Combination topical antimicrobial therapy providing Gram-positive coverage alongside polymyxin B for Gram-negatives
Choose Thymosin Alpha-1 if...
- Immune system strengthening
- Chronic infection support
- Cancer adjunct therapy
- Healthy aging immune support