How much water do I add to Thymalin?

You can reconstitute Thymalin with 0.5, 1, or 2 mL of bacteriostatic water. Each option produces a different concentration and syringe draw for the same dose. Use the calculator to see which is easiest to measure.

What does Thymalin cost per dose?

Cost per dose depends on vial size, price paid, and your dose. Enter your vendor's price in the Thymalin calculator to see cost per dose and monthly cost.

What is the reference dose for Thymalin?

The commonly referenced range is 5 up to 10 mg per day (start low, increase slowly), taken 10-day courses. This is reference information, not a recommendation. Talk to a licensed clinician.

What are the side effects of Thymalin?

Reported side effects of Thymalin include: Little Western human evidence.. Severity and frequency vary by person and dose.

Who should not take Thymalin?

Thymalin is generally not appropriate for: No formal Western contraindications established; Pregnancy; Immunosuppressive therapy, as a precaution. Talk to a licensed clinician before starting.

New?New to peptides?Start here →

Decoding

Thymalin_

Q: What is Thymalin?

Thymalin is a thymic bioregulator used for immune & aging. Thymalin is a peptide extract from the thymus, the gland that trains your immune system. In plain terms: taken in short courses, it is used to refresh immune function and support healthy aging, though Western human evidence is limited.

Q: Do you cycle Thymalin?

Taken in 10-day courses Course dosing is how this one is normally used. Where the course length comes from is the thing to check: for most compounds in this pattern it is convention rather than a tested schedule.

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

Immune & agingThymic bioregulatorResearch only

Common vial size10 mg

Dose5 up to 10 mg per day (start low, increase slowly)

Frequency10-day courses

RouteUnder the skin (subcutaneous)

StatusResearch only

MixYour choice, calculate it

CycledTaken in 10-day courses

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

What is Thymalin?

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

Overview

Thymalin is a peptide extract from the thymus, the gland that trains your immune system. In plain terms: taken in short courses, it is used to refresh immune function and support healthy aging, though Western human evidence is limited.

What it's used for

A thymus bioregulator taken in short courses to refresh immune function and support healthy aging. It is popular in longevity circles.

How does Thymalin work?

What it does in the body, and where.

Thymalin is an extract from the thymus, the gland that trains immune cells and shrinks progressively from adolescence onward.

01
It supplies thymic peptides
The premise is that supplying what an ageing thymus no longer makes restores some immune function.
02
Long-term Russian follow-up exists but is not independently replicated
Including reported mortality data from elderly cohorts, published by the originating institute and not reproduced elsewhere.

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.

Refreshing immune function with age, taken in short coursesResearch only
Healthy agingResearch only

How much, and do you cycle it?

The range, and whether you take breaks.

5 up to 10 mg per day (start low, increase slowly), 10-day courses. Taken in 10-day coursesCommunity practice

Course dosing is how this one is normally used. Where the course length comes from is the thing to check: for most compounds in this pattern it is convention rather than a tested schedule.

Compare cycling across compounds →

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 range: 5 up to 10 mg per day (start low, increase slowly)Community practice

Choose your mix

0.5 mL water25units · 20 mg/mL

Half a 100-unit syringe

1 mL water50units · 10 mg/mL

One full 100-unit syringe

Easiest

2 mL water100units · 5 mg/mL

Two full 100-unit syringes

your own mL

units · —

Enter your own volume

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

Your draw

100 / 100 units

Full calculator with reorder date →Read a syringe →

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 Thymalin 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.

What are the side effects and cautions?

Known cautions and warnings for this compound.

Who should avoid it

Check these before anything else.

No formal Western contraindications established
Pregnancy
Immunosuppressive therapy, as a precaution

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.

Reported as well tolerated in Russian studies
No modern Western controlled trials exist

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

Is Thymalin approved?

And where the numbers on this page come from.

Research only

No. Not FDA-approved.

Sold for research use only. Not cleared for human consumption or medical use.

DoseFrom research and community reports. No regulator has reviewed this dose.
Vial sizeFrom what vendors typically list; not a recommendation.
Reviewed22 July 2026

What else is like Thymalin?

Others in Immune support, side by side.

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

YOU ARE HERE

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)

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

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