Skip to content
Limited human dataNot FDA approved

Thymalin

Also known as: Timalin · Тималин · Thymus extract · Thymus polypeptides

Updated 19 sources

A Russian immune drug made from calf thymus: a mix of small peptides, not one molecule. Registered in Russia for immune deficiency at 5 to 20 mg into muscle daily for 3 to 10 days. Its fame comes from Khavinson's longevity cohort, which reported half the mortality with thymalin and lower still when combined with epithalamin, the extract behind epitalon. That data comes from one research group and has not been replicated in the West.
Calculate with ThymalinDosage chart

Quick facts

Routes
  • Intramuscular injection
  • Subcutaneous injection
Forms
  • Vial (powder)
Reported dose ranges
  • 5 to 20 mg (intramuscular injection)
  • 5 to 10 mg (subcutaneous injection)
Vial sizes
  • 10 mg, 15 mg, 20 mg
FDA status
  • Not FDA approved
WADA
  • Not confirmed

What people use Thymalin for

  • Immune recovery after infection, chemotherapy or radiotherapy
  • Anti-ageing bioregulator courses, classically with epitalon
  • Short courses 2 to 4 times a year for immune maintenance
  • Add-on in severe COVID-19, in small Russian studies

How it is thought to work. Russian label: it restores impaired immune reactivity, rebalances T and B lymphocytes and boosts cellular immunity and phagocytosis. Its developers name two dipeptides, KE (Lys-Glu) and EW (Glu-Trp), as its active parts. In cell work, thymalin lowered IL-1b, IL-6 and TNF-a output and pushed stem cells toward mature CD28+ T cells.

Thymalin dosing

10 protocols from studies, guides and community reports, grouped by goal. Tap a source badge to see where a number came from.

Immune restoration2

Immune restoration

Amount
5 to 10 mg
How often
Once daily
Route
IM, vial (powder)
Cycle
3 to 10 day course
Rest
May repeat after 1 to 6 months

Immune restoration (community)

Amount
5 to 10 mg
How often
Once daily
Route
IM, vial (powder)
Cycle
5 to 10 days, 2 to 4 times a year
Timing and details

Loading…

Other protocols: injected8

Immune deficiency treatment (Russian label)

Amount
5 to 20 mg
How often
Once daily
Route
IM, vial (powder)
Cycle
3 to 10 days by severity, 30 to 100 mg per course
Rest
Repeat course after 1 to 6 months if needed
Timing and details

Loading…

Prevention (Russian label)

Amount
5 to 10 mg
How often
Once daily
Route
IM, vial (powder)
Cycle
3 to 5 days
Timing and details

Loading…

Khavinson anti-ageing course

Amount
10 mg
How often
Once daily for 10 days in a row
Route
IM, vial (powder)
Cycle
10 days, every 6 months
Timing and details

Loading…

Chemotherapy support

Amount
5 to 10 mg
How often
Once daily
Route
IM, vial (powder)
Cycle
5 to 7 days, during or between chemotherapy cycles
Timing and details

Loading…

Recovery after infection

Amount
5 mg
How often
Once daily
Route
IM, vial (powder)
Cycle
3 to 5 days; repeat if immune markers stay low

Short courses (Russian clinical use)

Amount
5 to 10 mg
How often
Daily
Route
IM, vial (powder)
Cycle
5 to 10 days
Timing and details

Loading…

Anti-ageing maintenance (community)

Amount
5 to 10 mg
How often
Once daily
Route
SubQ, vial (powder)
Cycle
10 days, every 3 to 4 months
Timing and details

Loading…

Community range

Amount
5 to 20 mg
How often
Daily
Route
IM, vial (powder)
Cycle
5 to 10 days, 1 to 2 times a year
Timing and details

Loading…

Doses shown are what sources report, labelled by origin. Not medical advice.

Full Thymalin dosage guideEvery titration step in syringe units, missed doses and how to mix.

Vial strengths and syringe units

Every Thymalin vial size with the water volumes sources use. Units are what to draw on a U-100 insulin syringe, worked out exactly.
Thymalin: concentration and U-100 syringe units for each vial size and water volume
WaterStrength5 mgdose, units10 mgdose, units20 mgdose, units
10 mg vial
1 mLRegulatory10 mg/mL500.5 mL1001 mL2002 mL2 draws
2 mLRegulatory5 mg/mL1001 mL2002 mL2 draws4004 mL4 draws
15 mg vial
1 mLRegulatory†15 mg/mL33.30.333 mL66.70.667 mL133.31.333 mL2 draws
2 mLRegulatory†7.5 mg/mL66.70.667 mL133.31.333 mL2 draws266.72.667 mL3 draws
20 mg vial
1 mLRegulatory†20 mg/mL250.25 mL500.5 mL1001 mL
2 mLRegulatory†10 mg/mL500.5 mL1001 mL2002 mL2 draws
Units are on a U-100 insulin syringe (100 units = 1 mL). U-50 and U-30 barrels read the same units.† Water volume sourced for a different vial size. The math is exact either way.Water volumes from

Doses shown are what sources report, labelled by origin. Not medical advice.

Calculate with this peptideYour vial, your water, your dose: Thymalin in syringe units, with the math shown.

Thymalin side effects

What trials and labels report, kept apart from what users and guides report. Frequencies are worded as each source states them.

Reported in studies and labels1

From clinical trials and regulatory documents.

  • Allergic reaction

    Possible; the only adverse effect the Russian label lists

Reported by users and guides3

From community reports and dosing guides. Not measured rates.

  • Injection-site reactions

    Reported

  • Allergy in people sensitive to beef protein

    Possible, since it is a bovine extract

  • Generally well tolerated

    Consistently described as well tolerated in community reports

All 4 Thymalin side effects and how people manage themEvery management tip, who should not use it, and side-effect questions.

Who should avoid it

  • Pregnancy and breastfeedingCondition

    Contraindicated on the Russian label.

  • Known intolerance to thymalin or glycineCondition

    Contraindicated on the label; use with caution after past severe allergies.

  • Autoimmune diseaseCondition

    Raising T-cell activity could worsen it, so guides say avoid.

  • Immunosuppression after an organ transplantCondition

    It works against the drugs that keep the transplant safe; guides urge caution.

Storage

Powder (before mixing)

Temperature
2 to 25 °C

Russian label: 2 to 25 C. An older label text says dry, dark and no warmer than 20 C, with a 3-year shelf life.

Powder (before mixing)

Temperature
-20 to 8 °C

Research vials: fridge at 2 to 8 C away from light, or the freezer at -20 C for long-term storage. Avoid repeated temperature swings.

Mixed vial

Label and one guide: dissolve right before the injection and do not keep the mixed solution.

Mixed vial

Temperature
2 to 8 °C
Use within
28 days

With bacteriostatic water, community convention is the fridge at 2 to 8 C away from light for about 28 days. No thymalin stability study backs that figure; saline has no preservative, so its window is shorter.

Mixed with: Sodium chloride 0.9% (label); community uses bacteriostatic water

Mixing. The label dissolves each vial in 1 to 2 mL of saline right before injecting into muscle. Community sites use bacteriostatic water and often inject under the skin. At label doses a 10 mg vial covers only one or two injections.

Stacks people report

Combinations from guides and community posts, with the reason given.
  • Epitalon

    The classic Khavinson pairing: thymalin for the thymus, epitalon for the pineal gland, often 10 mg of each daily for 10 days every 6 months. In the Russian cohort the combination of thymalin and epithalamin (epitalon's parent extract) gave the largest reported drop in mortality.

  • Thymosin Alpha-1

    A niche community immune stack for times of illness.

  • Pinealon

    Part of a niche community bioregulator stack with Vilon for immune, cell and brain targets.

Compare Thymalin

Evidence and legal status

Evidence: limited human data

Almost all human data come from one Russian research network. A cohort of 266 elderly people followed 6 to 8 years reported 2.0 to 2.1-fold lower mortality on thymalin and 2.5-fold on thymalin plus epithalamin; the abstract does not describe randomization. Small Russian studies used it in severe COVID-19. No Western randomized trial exists and ClinicalTrials.gov lists none.

FDA and WADA

Not FDA approved

No approval, no trial program and not on FDA's compounding lists.

Not FDA approved and never evaluated by FDA. It appears on neither FDA's list of compounding bulk substances with safety risks nor its 503A nominations list, and no US trial is registered. Registered as a prescription drug in Russia.

Not approved by FDA, EMA or other major Western regulators. WADA 2026 does not name thymalin. S0 covers substances with no government approval for human use; thymalin is registered in Russia, so S0 does not appear to apply. That is our reading; no WADA ruling was found.

WADA: Not confirmed

Thymalin questions

What is thymalin?

A freeze-dried extract of calf thymus: a mixture of small peptides, not a single molecule. It is a registered prescription drug in Russia, sold as 10 mg vials for injection into muscle.

Is thymalin a dipeptide?

No. Some vendors label it a 2 to 4 amino acid peptide, which is wrong. Its developers name the dipeptides KE (Lys-Glu) and EW (Glu-Trp) as its active parts, and EW on its own is a separate drug, Thymogen.

What is the dose?

The Russian label gives adults 5 to 20 mg into muscle once daily for 3 to 10 days, 30 to 100 mg per course, repeated after 1 to 6 months if needed. For prevention it is 5 to 10 mg daily for 3 to 5 days.

How often do people run courses?

In short pulses, never continuously. Community users run 5 to 10 mg daily for 5 to 10 days, 2 to 4 times a year, or a 10-day course every 3 to 4 months, often with epitalon.

How many units is 5 mg?

With 10 mg in 1 mL (10 mg/mL), 5 mg is 0.5 mL, or 50 units on a U-100 syringe. With 10 mg in 2 mL it is 100 units, a full 1 mL syringe. Use the calculator for your own mix.

Into muscle or under the skin?

The label and published Russian use are into muscle, dissolved in saline. Community sites often inject under the skin with bacteriostatic water, which has no controlled basis.

Does thymalin extend life?

One Russian cohort of 266 older adults reported about half the mortality over 6 to 8 years with thymalin, and 2.5 times lower with thymalin plus epithalamin. The data come from the developers' own group and have not been replicated elsewhere.

Thymalin or thymosin alpha-1?

Thymosin alpha-1 is one defined peptide with international trials and approvals in several countries. Thymalin is a thymus extract backed mainly by Russian studies. Guides rate thymosin alpha-1's evidence much stronger.

Why pair it with epitalon?

Both come from Khavinson's bioregulator program: thymalin for the thymus, epitalon for the pineal gland. It is the classic community anti-ageing stack.

Was it used for COVID-19?

Small Russian studies added it to standard care for severe COVID-19 and reported faster drops in IL-6, CRP and D-dimer and higher lymphocyte counts. One reported lower hospital mortality, but its English and Russian abstracts give different figures.

What are the side effects?

The Russian label lists only possible allergic reactions. Guides add injection-site reactions and the chance of an allergy in people sensitive to beef protein. Most of the safety reporting comes from the program that developed it.

Who should avoid it?

The label rules out pregnancy, breastfeeding and known intolerance. Guides add autoimmune disease and transplant recipients on immunosuppressants.

How should I store it?

The Russian label stores the powder at 2 to 25 C and dissolves it right before the injection. Research vials are often kept in the fridge or freezer. Community users who mix with bacteriostatic water keep it 2 to 8 C for about 28 days, a convention with no stability study.

Is thymalin FDA approved?

No, and FDA has never evaluated it. It appears on neither FDA's compounding safety-risk list nor its 503A nominations list.

What is the half-life?

No source publishes one. As a mixture of peptides it has no single half-life.

Ask about Thymalin

Answers come from this site's pages only, with a link to each source.

Sources

19 sources, each checked by date. Record updated Oct 24, 2026. Numbers are restated in our own words and labelled by where they came from.

Vendor guide1

  1. How to store thymalin long termVendor guide · checked Oct 24, 2026

Competitor guide5

  1. Thymalin profilepeptideprotocolwiki.com · checked Oct 24, 2026
  2. Thymalin dosing calculatorpeptideprotocolwiki.com · checked Oct 24, 2026
  3. Thymalin reconstitution guidethepeptidecatalog.com · checked Oct 24, 2026

Community-reported1

  1. Thymalin community protocols and reportspeptideprotocolwiki.com, via a competitor guide · checked Oct 24, 2026