Peptide Medicine
Thymosin Alpha-1: Immune Support, Evidence, and Safety
Evidence checked by HealthRX.com Editorial Team · Last evidence check
What is thymosin alpha-1?
Thymosin alpha-1 is a peptide originally derived from the thymus gland, which trains the immune system. A synthetic version is used as an immune modulator and is sold in many countries as Zadaxin.
How does thymosin alpha-1 work?
Thymosin alpha-1 helps mature and regulate T cells, a central part of the immune system, and can influence the balance of immune signaling. This is why it has been studied as an add-on in infections and as a vaccine adjuvant. [1]
What does the research show?
Thymosin alpha-1 is approved and used in many countries for hepatitis B and C and as an immune adjuvant, and it has been studied in sepsis and other conditions. Evidence quality varies by indication, and it is not FDA approved in the United States. [1]
How is thymosin alpha-1 dosed?
Where approved, thymosin alpha-1 is given as a subcutaneous injection, often twice weekly, with the dose set by the treating clinician and indication. Compounded or off-label regimens vary and should be provider-directed.
Is thymosin alpha-1 safe?
Thymosin alpha-1 is generally well tolerated where it is used clinically, with injection-site reactions the most common complaint. As an immune modulator, it should be used under medical supervision, particularly in people with autoimmune conditions.
Is thymosin alpha-1 legal and FDA approved?
Thymosin alpha-1 is approved in some countries but is not FDA approved in the United States. Its 503A nomination was withdrawn, which does not erase FDA's published safety concerns or create a compounding permission.
How to get Thymosin Alpha-1 online
Thymosin Alpha-1 is available through HealthRX.com after an online visit with a licensed provider, who reviews your history and, when appropriate, issues a prescription that a licensed US pharmacy dispenses and ships to you. Thymosin Alpha-1 starts at $224 per 5mg vial.
Because Thymosin Alpha-1 is a immune-modulating peptide and prescription-only, it cannot be bought over the counter. What you pay depends on the dose and quantity your provider recommends. You can begin the online visit in a few minutes and are only prescribed if a provider determines it is appropriate.
Frequently asked questions
Is thymosin alpha-1 FDA approved?
No. It is approved in some countries as Zadaxin but is not FDA approved in the United States. Its 503A nomination was withdrawn.
What is thymosin alpha-1 used for?
Abroad it is used for hepatitis B and C and as an immune adjuvant, and it has been studied in other conditions such as sepsis.
Is thymosin alpha-1 safe?
It is generally well tolerated where used clinically, with injection-site reactions most common. People with autoimmune conditions should be especially cautious.
Citations
This guide is educational and is not a substitute for individualized medical advice. Thymosin Alpha-1 is prescription-only and requires evaluation by a licensed provider.