Peptide Decoding
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Decoding

Thymosin Alpha-1_

Also known as thymalfasin, Zadaxin, Ta1

A well-studied shot that tunes up the immune system.

Immune supportImmune peptideClinical use
Common vial size5 mg
Dose1.6 mg per dose
Frequency2x per week
RouteUnder the skin (subcutaneous)
StatusApproved abroad / research in US
MixYour choice, calculate it
CycledGiven as a defined course, typically twice weekly over months

Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.

01

What is Thymosin Alpha-1?

Plain language first. The technical label stays, but it never stands alone.

Overview

Thymosin Alpha-1 is a 28-amino-acid peptide made by the thymus that helps direct immune defenses. In plain terms: it tunes up the immune system to respond better to infection, and it is well studied and used abroad as an add-on therapy.

What it's used for

A shot that tunes up your immune system, used for chronic infections, immune resilience, and as an add-on therapy abroad. It is well studied.

02

How does Thymosin Alpha-1 work?

What it does in the body, and where.

Thymosin alpha-1 is made by your thymus, the gland that trains your immune cells. It is one of the better-studied peptides here and is an approved drug in more than thirty countries.

  1. 01
    It matures and directs T cells
    T cells are the part of your immune system that recognises specific threats, and this peptide helps them develop and respond.
  2. 02
    The response is tuned, not amplified
    It appears to improve how well the immune system responds rather than simply increasing activity, which matters because more immune activity is not always better.
  3. 03
    Approved abroad, not in the US
    Used for hepatitis B and C and as an adjunct in some cancers in other countries. It has not been FDA-approved.
Where it acts
Thymus and lymph nodes

Where this compound is thought to act.

03

What else is it used for?

Each use below carries its own evidence level. Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.

  • Helping the immune system fight chronic hepatitis B, approved in more than 35 countries as Zadaxin but not in the United StatesClinical use
  • Supporting the immune system alongside cancer treatment in some countriesClinical use
  • Severe infection and sepsis, where a large 2025 trial did not show a clear benefitInvestigational
04

How much, and do you cycle it?

The range, and whether you take breaks.

1.6 mg per dose, 2x per week. Given as a defined course, typically twice weekly over monthsClinical use

Where it is registered, it is prescribed as a course rather than continuously: commonly twice-weekly injections over a set number of months for hepatitis B, or a short course alongside a vaccine. The course length comes from the indication, not from tolerance.

Compare cycling across compounds →

05

How do I dose and price it?

Enter your vial and your dose. Pick a mix. We show the draw and the cost.

The vial holds a fixed amount of drug. Adding more water does not make more drug, it just spreads it thinner, so you draw a bigger number on the syringe for the same dose.

Your vial size (mg)
Printed on the vial.
What you paid per vial
$
Used for cost per dose only.
Your dose (mg)
Commonly referenced dose: 1.6 mg per doseClinical use

Choose your mix

your own mL
units · —
Enter your own volume

Measuring the water1 mL = one full 100-unit syringe.

Your draw

64 / 100 units
Full calculator with reorder date →Read a syringe →
06

How do you store it?

Before mixing, and after.

Dry powder in the freezer or fridge. Once mixed, fridge, and use within about a month.

Unmixed lyophilized Thymosin Alpha-1 keeps for a long time cold. Once you add water the clock starts: most reconstituted vials hold up for roughly 28 to 30 days at fridge temperature. Keep it out of light, and do not freeze it after mixing.

07

What are the side effects and cautions?

Known cautions and warnings for this compound.

22 July 2026Not FDA-approved in the United States, where it holds only orphan-drug designation. It is approved and used in more than 35 other countries.

Who should avoid it

Check these before anything else.
  • Immunosuppressive therapy, including after an organ transplant
  • Pregnancy

Stop and get help

These are emergencies. Seek care.
  • Signs of an allergic reaction
  • Worsening of an autoimmune condition

Common effects

Expected, and usually mild.
  • Injection-site redness, which is the most common effect
  • Generally very well tolerated
  • Occasional short-lived fatigue

Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.

08

Is Thymosin Alpha-1 approved?

And where the numbers on this page come from.
Clinical use

Yes. Approved for clinical use.

Not FDA-approved in the United States, where it holds only orphan-drug designation. It is approved and used in more than 35 other countries.

  • DoseFrom product labeling and clinical guidelines.
  • Vial sizeFrom what vendors typically list; not a recommendation.
  • Reviewed22 July 2026
09

What else is like Thymosin Alpha-1?

Others in Immune support, side by side.

If you're weighing Thymosin Alpha-1, it's worth reading Thymalin, Vilon, and Glutathione in the same class.

YOU ARE HERE
Thymosin Alpha-1

A well-studied shot that tunes up the immune system.

Clinical use
Dose
1.6 mg per dose
How often
2x per week
THYMA
Thymalin

A thymus peptide taken in courses to refresh immune function and aging.

Research only
Dose
5 up to 10 mg per day (start low, increase slowly)
How often
10-day courses
Vilon

A tiny bioregulator taken in courses for immunity and aging, with thin evidence.

Research only
Dose
Varies (course-based)
How often
Courses
GSH
Glutathione

Your body's master antioxidant, taken for glowing skin and detox support.

OTC / supplement
Dose
250 up to 1000 mg per day (start low, increase slowly)
How often
Daily (oral)
10

What these words mean

Show glossary +
Titrate
Starting at a low dose and increasing it slowly over time so your body adjusts and side effects stay mild.
Subcutaneous
An injection just under the skin, into the fat layer, usually with a short, thin insulin needle.
Intramuscular (IM)
An injection into a muscle, using a longer needle.
Reconstitution
Mixing a powdered peptide with liquid (bacteriostatic water) so it can be drawn into a syringe.
Bacteriostatic water
Sterile water with a tiny amount of preservative, used to mix powdered peptides.
Concentration
How strong the mixed peptide is, in milligrams per milliliter (mg/mL). More water makes it weaker; less water makes it stronger.
Units (on the syringe)
The marks on an insulin syringe. 100 units equals 1 mL. They measure how much liquid you draw, not the dose in milligrams.
mcg and mg
Units of dose. 1 milligram (mg) equals 1,000 micrograms (mcg).
GLP-1
A natural gut hormone that lowers appetite and blood sugar. Drugs that copy it, like semaglutide, are used for weight loss.
Growth hormone secretagogue
A compound that nudges your body to release more of its own growth hormone, rather than injecting the hormone itself.
Half-life
How long a compound stays active in your body. A longer half-life means you inject less often.
Peptide vs small molecule
A peptide is a short chain of amino acids. A few items here (like MK-677 or methylene blue) are small molecules, not true peptides, but people use them the same way.
Research only
No approved dose or use in people. Sold for research and not reviewed by the FDA for safety or quality.
Investigational
Still being tested in clinical trials and not yet approved or legally sold for general use.
Banned in drug-tested sport
Prohibited by the World Anti-Doping Agency (WADA); using it can disqualify a competing athlete.

Last reviewed 22 July 2026