Thymosin Alpha-1
Tα1, 28-amino-acid thymic peptide
An immune-modulating thymic peptide approved in dozens of countries, with the most substantial regulatory footprint of anything on this site.
Last reviewed · 1 references
How it works
Thymosin alpha-1 is produced by the thymus and modulates T-cell maturation and dendritic cell function. Rather than stimulating the immune system indiscriminately, it appears to restore balance — which is why it has been studied both in immune deficiency and in conditions with excessive inflammation.
Human trials. Tested in controlled human trials. Still read the sample sizes — many are small.
What the research reports
- Approved in over 30 countries for hepatitis B, hepatitis C and as a vaccine adjuvant
- Randomised trials in sepsis reporting mortality benefit
- Studied extensively during COVID-19 for immune restoration
- Reduced inflammatory markers in several trial settings
What it has not been shown to do
- Not FDA-approved in the United States
- No cognitive or mood endpoint trials
- The mental-health link is inferential, via inflammation
Dosing reference
Clinical protocols commonly use 1.6 mg subcutaneously twice weekly, under medical supervision.
Calculate my dose for Thymosin Alpha-1- Routes studied
- Subcutaneous
- Half-life
- Roughly 2 hours; immune effects persist far longer
- Cycle length in the literature
- Clinical courses run weeks to months depending on indication
Working out a draw volume from a vial? Use the free reconstitution calculator.
Side effects and contraindications
Reported side effects
- Injection-site reaction
- Transient flu-like symptoms
Do not use if
- Immunosuppressed transplant recipients — immune modulation can threaten graft tolerance
- Autoimmune disease without specialist oversight
- Pregnancy and breastfeeding
The practice that shares the mechanism
The inflammation-depression link is one of the better-supported ideas in modern psychiatry. Sleep deprivation raises inflammatory cytokines measurably within days, and chronic stress does the same — which makes rest and regulation direct interventions on the same target.
What amplifies it
- Sleep — the fastest way to raise inflammatory markers is to stop sleeping
- Omega-3 intake and resolution of inflammation
- Stress reduction, which lowers IL-6 and CRP in trial settings
Mechanism hubs
Common questions
- A great deal, on current evidence. Inflammatory cytokines including IL-6 and TNF-alpha are elevated in a meaningful subset of people with depression, and injecting healthy volunteers with inflammatory stimuli reliably produces depressive symptoms. That does not mean an immune peptide treats depression — it means inflammation is a legitimate target.
Sources & evidence notes
Tested in controlled human trials. Still read the sample sizes — many are small.
Confidence score 33/100
Limited confidence
Animal or mixed preclinical work. Enough to justify interest, not enough to predict an outcome in a person.
- 1.
Critical Care, 2013 · Source (opens in a new tab)
Human RCTStrong gradeRandomised controlled trial in people — the strongest single source type here.