Thymosin Alpha-1 (Thymosin Alpha-1 (Thymalfasin))
A thymic peptide approved in over 35 countries for immune modulation. Enhances T-cell function, dendritic cell maturation, and anti-viral/anti-tumor immunity without overstimulation.
How it works
Activates toll-like receptors (TLR2, TLR9) on dendritic cells, promotes T-cell maturation and differentiation, enhances NK cell cytotoxicity, and modulates cytokine profiles.
Key facts
- Molecular weight: 3108.3 Da
- Half-life: ~2-3 hours
- Bioavailability: ~85% subcutaneous
- Storage: Lyophilized: 2-8°C. Reconstituted: 2-8°C for up to 14 days.
Dosing overview
- Typical dose: 1.6-3.2 mg
- Frequency: 2-3x per week
- Duration: 4-12 weeks or longer
- Route: Subcutaneous injection
Protocol notes
- A common protocol is 1.6 mg twice weekly, stepping to 3.2 mg or 3x weekly during active immune challenges.
- For chronic immune support, many run lower, less frequent dosing (e.g. 1.6 mg twice weekly) over longer periods.
- Often paired with other immune peptides (LL-37, KPV) during acute illness windows.
Reported benefits
- Enhanced T-cell immunity
- Anti-viral activity
- Dendritic cell activation
- Cancer immunosurveillance
- Vaccine adjuvant effects
Possible side effects
- Injection site discomfort
- Mild fatigue
- Low-grade fever (rare)
- Muscle aches
Research
- Thymalfasin in hepatitis B treatment (2019): Improved sustained virologic response rates by 25% when combined with standard antiviral therapy.
- Thymosin alpha-1 immune modulation in COVID-19 (2021): Reduced mortality and improved T-cell counts in severe COVID-19 patients as adjunctive therapy.
Community reviews of Thymosin Alpha-1
- dose_math_derek rated it 5/5 - Noticed clear benefits within weeks: Added Thymosin Alpha-1 to my protocol about 6 weeks ago and it has earned its place. The benefits became noticeable around week 2-3 and have been consistent since. What I appreciate about this compound is the predictability. It does what the research suggests it should do, at roughly the timeline you would expect. No surprises, no dramatic swings, just steady improvement. No notable side effects to report at my dose. Sourcing is always the challenge with research compounds, insist on third-party testing. Storage and reconstitution per standard protocols. Plan to continue.
- n_of_one rated it 5/5 - Worth adding to the protocol: Thymosin Alpha-1 has been a worthwhile addition. I am data-driven and tracked relevant markers before, during, and after. The improvement is measurable and correlates with the intervention timeline. What sets this apart from some compounds I have tried is the consistency. Benefits did not fluctuate wildly or disappear. They built up and maintained. That gives me confidence in the mechanism. Tolerance has been excellent. Nothing in my bloodwork or subjective experience raised any flags. This is the kind of compound that does its job quietly without causing problems. Exactly what you want.
- measured_mike rated it 5/5 - Solid compound with real results: Been using Thymosin Alpha-1 for about 3 weeks and the results are clear. Not overnight dramatic, but a steady, consistent improvement that became undeniable by the end of the first month. The mechanism makes sense based on what I have read in the literature, and my subjective experience matches the expected timeline. Benefits built gradually and plateaued at a good level. Side effects were minimal to none at the dose I used. Followed proper protocols for sourcing, storage, and administration. Would recommend to others who have done their research and have realistic expectations.
- cycle_sage rated it 5/5 - Genuinely effective after 6 months: Been using Thymosin Alpha-1 for about 6 months and the results are clear. Not overnight dramatic, but a steady, consistent improvement that became undeniable by the end of the first month. The mechanism makes sense based on what I have read in the literature, and my subjective experience matches the expected timeline. Benefits built gradually and plateaued at a good level. Side effects were minimal to none at the dose I used. Followed proper protocols for sourcing, storage, and administration. Would recommend to others who have done their research and have realistic expectations.
- nerdy_nomad340 rated it 4/5 - Helped me stay steady through a rough winter stretch: I tried Thymosin Alpha-1 over about 12 weeks when I was getting run down here in India, teaching yoga in a dusty season and also doing early morning walks that kept leaving me a bit wiped. For me, it seemed to help me bounce back faster after those little viral bugs that keep going around. I still had one annoying week where I felt off, so not a fairy tale, but overall I was getting through the season more steadily.
- vet945 rated it 4/5 - steadier winters, less drama than i expected: i ran thymosin alpha-1 for about 10 weeks because i’m in a gym all day in singapore, breathing everybody’s lovely little coughs and sniffles, and at my age i’m not keen on getting flattened by every bug going around. for me it seemed to make those rough patches less frequent, but the best bit was how steady i felt overall. i still preferred cjc-1295 with ipamorelin for recovery, though, that one felt more useful for my training.
Compare Thymosin Alpha-1
Research and educational reference only. Not medical advice.