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Immune system

Thymalin

A thymus peptide preparation from the Khavinson program, meant to support the immune system, with data mostly from one research line.

2 min read 8 sources

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Thymalin vial with white powder and the black TPD label on a white podium with a glowing ring, surrounded by glass spheres in a bright lab
Compound approved · in Russia since 1982

Summary

At a glance

Sources checked on 26 Oct 2026

Older adults in the long-term study
266 people

observed for 6 to 8 years, Thymalin and Epithalamin, without placebo2

Lower mortality
2.0 -fold

Thymalin group against control, 2.0 to 2.1-fold according to the authors2

Less IL-6 in COVID-19
5.5 -fold

inflammation marker after standard care plus Thymalin, 42 patients3

Trials in the registry
0 trials

no trial with Thymalin on ClinicalTrials.gov or the WHO search portal, as of 26 Oct 20268

  • Thymalin is a mixture of peptides from the thymus of calves. It comes from the Russian Khavinson programme and has been approved there since 1982 as a medicine to support the immune system.63
  • The developer group names mainly the dipeptides KE and EW as active substances. EW later became the single peptide Thymogen.56
  • In a long-term observation of 266 older people mortality in the Thymalin group was about half that of the control group according to the authors. There was no placebo group.2
  • In 42 patients with COVID-19 inflammation and clotting values fell more with Thymalin than with standard care alone. In cell culture it promoted the maturation of stem cells into T cells.34
  • Large independent studies are missing and none is in the registry. Everything here is the state of research, not a recommendation.18
Profile

Updated May 2026

Class
Thymus peptide

bioregulator

Use
Subcutaneous

in mg

Half-life
short
Status
Data mostly from the Khavinson program
Sizes
10 to 20 mg

2 sizes in the shop

Contents 15 sections
  1. At a glance
  2. What is Thymalin?
  3. How it works
  4. What you need
  5. Reconstitution
  6. Dosing
  7. Injection
  8. What the research shows
  9. Research status
  10. Side effects
  11. Storage
  12. Related compounds
  13. FAQ
  14. Glossary
  15. Sources

What is Thymalin?

Thymalin is a peptide preparation from the thymus, the gland responsible for the maturation of immune cells (T cells). It comes from the Russian Khavinson program on peptide bioregulators and is meant to support age-related declining immune function.

Up front: most research comes from one research line, mostly from Russia.

Comparison

Mixture and single peptides

Thymalin next to the two dipeptides that act in it according to the developer group, as stated in the TPD lexicon. Tap a card to open its entry.

Peptide mixture from the thymus Thymalin KE EW 2 of 2 compounds
Dipeptide KE Vilon KE EW 1 of 2 compounds Dipeptide EW Thymogen KE EW 1 of 2 compounds

Simplified: Thymalin contains many peptides. That KE and EW are the active substances is stated by the developer group itself. 5

How it works

The thymus produces fewer active T cells with age. Thymalin is meant to support this maturation and regulate the balance of the immune system. In the available works this is associated with a better immune response and, in animal models, even a longer lifespan.

Where it acts

Where Thymalin acted in studies

Tap a point or a card. Grey = observed, no confirmed receptor is known.

  1. Blood and immune cells

    Blood stem cells matured into T cells in cell culture, CD28 raised 6.8-fold4

    Observed in trials
  2. Lungs

    COVID pneumonia: inflammation and clotting values fell more than without Thymalin3

    Observed in trials
Translucent glass gland lobe with clusters of small round cells, blue particles floating between them, part of the cells glowing brightly
Maturation of immune cells in the thymus. Symbolic image.

What you need

Supplies

2 things, numbered as in the picture

Tick off what you already have. Vial and BAC water are our real shop photos at the same size.

Thymalin vial and bacteriostatic water at the same size with the black TPD label, next to two U-100 insulin syringes, two alcohol swabs and a sharps container with a blue lid

  1. Thymalin vial

    The thymalin vial (lyophilized powder).

    In the shop

  2. Water and supplies

    Bacteriostatic water, U-100 insulin syringes, alcohol swabs.

    In the shop

Reconstitution

Use the peptide calculator. A 10mg vial with 2ml water gives 5mg per ml, 10mg is then 40 units on the U-100 syringe. Just add the water to the vial and let it dissolve.

Step by step

Dissolving the powder

Four steps, the same for every vial size.

  1. 1Wipe the cap

    Clean the rubber stopper with an alcohol swab.

  2. 2Add BAC water

    Just add it, it does not matter if it hits the powder directly.

  3. 3Swirl or shake

    Until everything has dissolved, both are fine.

  4. 4Draw up

    With the U-100 insulin syringe.

Less water higher concentration fewer units on the syringe Example: 10 mg + 2 ml = 5 mg/ml

Dosing

Dosing

Dosing, titration and syringe

Loading the dosing information …

  • Getting started and stepping up, drawn as a staircase
  • Units on the U-100 syringe for every step
  • How long one vial lasts

Injection

The injection is subcutaneous, into the fat layer under the skin. Common spots are the abdomen (keep about two finger-widths clear of the navel), the front and the inner side of the thigh, or the back of the upper arm.

The short version:

Injection

Where and at what angle

Pick a spot or switch the angle. Subcutaneous means: into the fat layer, not the muscle.

Rotate the spot each time, never the same one twice in a row.

90°More fat under the skin

Rule of thumb: where there is more fat under the skin, insert straight at 90 degrees. In lean people with little fat, 45 degrees, so the needle stays in the fat layer. Simplified diagram.

  1. Clean the spot with an alcohol swab and let it dry

  2. Pinch up a small fold of skin

  3. Insert the needle: at 90 degrees where there is more fat under the skin, at 45 degrees in lean people with little fat

  4. Inject slowly, wait a moment, then withdraw

  5. Put the needle straight into the sharps container

Rotate the site each time so the tissue does not get irritated. Never the same spot twice in a row.

What the research shows

The Khavinson program has published works on thymus peptides over decades (overview: Khavinson, 2002), with effects on immune function and, in animal models, on lifespan. The read must stay honest: the data come mostly from one research line, large independent studies are missing.

Study results

What the trials measured

Interactive: switch tabs, tap points, show or hide arms. Arms are named relative to each other, no dosing advice.

Inflammation and clotting in COVID-193

Change from start to after treatment, in percent, 50 against 42 patients

IL-6 (inflammatory messenger)3
Standard care -29%
Standard plus Thymalin -82%
CRP (inflammation marker)3
Standard care -40%
Standard plus Thymalin -90%
D-dimer (clotting)3
Standard care -52%
Standard plus Thymalin -82%

Calculated from the mean values in the full-text tables. Allocation by envelope, no placebo, the groups also received various other drugs. A single study from Russia.

How much less often people died2

Against the control group, 266 older people, observed for 6 to 8 years

Thymalin2
Thymalin 2.0-fold
Epithalamin2
Epithalamin 1.6-fold
Both together2
Thymalin plus Epithalamin 2.5-fold
Both yearly for 6 years2
Both yearly for 6 years 4.1-fold

Lower bound of the ranges in the abstract (2.0 to 2.1 and 1.6 to 1.8). Given in the first 2 to 3 years, no placebo group, group sizes not stated in the abstract, data from the developer group.

Maturation of stem cells into T cells4

More CD28, a marker of mature T cells, compared with cells without Thymalin

CD28 on the cells4
Cell culture with Thymalin 6.8-fold

At the same time the stem cell markers CD44 and CD117 fell to a half to a third. Human blood stem cells in cell culture, not tested in humans.

Two-lobed gland of frosted glass on a glass base next to an hourglass and a green plant at a bright window
Long-term observation in older adults, without placebo. Symbolic image.

Research status

Where the research stands

Thymalin is approved in Russia, but neither ClinicalTrials.gov nor the WHO search portal with the other registries lists a trial on it. The controlled trials in humans are publications by the developer group without a registry number. As of 26 Oct 2026. 87

  1. Preclinical Thymus extract in immune cells and animals
  2. Phase 1 no registered trial
  3. Phase 2 no registered trial
  4. Phase 3 no registered trial
  5. Approval in Russia since 1982
Approved in Russia as an immunomodulator since 1982. Not approved in the EU or the US.3
Show all 2 trials on a timelineHide timeline 2 completed 0 running 2 with results
Without phase

Bar: start to primary endpoint (planned for running trials), for published trials without a stated period the year of publication. Green = completed, blue = progress until 26 Oct 2026.

Side effects

  • Well tolerated in the available reports, mainly local reactions.
  • Solid, independent safety data are limited.

Storage

Before mixing the powder is robust, normal room temperature (around 20 to 25 degrees) is fine, ideally kept in the dark. After mixing, keep in the fridge (2 to 8 degrees), do not freeze. It stays good there for at least 4 to 6 months with barely any loss of potency, in practice considerably longer. Swirl or shake to mix, both are fine.

Shelf life

How long it keeps

Undissolved (powder) Room temperature, around 20 to 25 degrees, dark

Robust, no fridge needed.

Dissolved (mixed) Fridge, 2 to 8 degrees, do not freeze

At least 4 to 6 months with barely any loss of potency. The bacteriostatic water brings a preservative.

  • Keep it dark
  • Dissolved: 2 to 8 degrees
  • Note the mixing date on the vial
Nine vials with white powder and blue caps in the door shelf of a bright fridge
Powder dark at room temperature, once dissolved into the fridge (2 to 8 degrees), stable there for at least 4 to 6 months. Symbolic image.

Related

Related compounds

Same compounds or a different path: all in the TPD lexicon.

Thymalin
Thymogen The dipeptide EW, isolated from Thymalin and rebuilt Vilon The dipeptide KE from the Khavinson programme Epitalon From the pineal gland, combined with Thymalin in the long-term study Thymulin Different peptide from the thymus Thymosin Alpha-1 Different thymus peptide Testagen Short peptide from the same programme

FAQ

Common questions about Thymalin

Short answers, each backed by the sources below.

What is Thymalin?

A mixture of peptides obtained from the thymus of calves using mild acid. It comes from the Khavinson programme in St. Petersburg and is regarded there as an immune corrector.6

Is Thymalin approved?

In Russia yes: according to the developer group approved by the Ministry of Health as an immunomodulator since 1982. Not in the EU or the US. The ClinicalTrials.gov registry lists no trial on Thymalin.38

What is the active substance?

The developer group names the dipeptides KE and EW. The dipeptide EW was isolated from Thymalin and rebuilt as Thymogen. In blood cells from four donors Thymalin, KE and EW lowered the messengers IL-1β, IL-6 and TNF-α 1.4 to 6-fold after an inflammatory stimulus.56

What does the long-term study in older adults show?

266 older people were observed for 6 to 8 years, the peptides were given in the first 2 to 3 years. In the Thymalin group mortality was 2.0 to 2.1-fold lower according to the authors and respiratory infections were less common. Placebo and independent replication are missing.2

What about COVID-19?

A Russian study gave 42 patients with COVID pneumonia Thymalin in addition, 50 received standard care only. IL-6, CRP and D-dimer fell much more with Thymalin and the lymphocyte count normalised. The study was small and without placebo.3

Which side effects are known?

There are no solid figures. The published papers give no frequencies in their abstracts. As an immunomodulator caution in autoimmune disease is plausible, but there are no data.23

Glossary

Terms explained briefly

Dotted words in the text open these explanations directly.

Blood stem cells
Cells from which all blood and immune cells arise.
D-dimer
A fragment from dissolved blood clots. High values indicate active clotting.
Dipeptide
A chain of exactly two amino acids, such as KE (lysine, glutamic acid) or EW (glutamic acid, tryptophan).
IL-6
Interleukin 6, an inflammatory messenger. Often strongly raised in severe COVID-19.
Immunomodulator
A substance meant to stimulate or dampen the body's defences.
Khavinson programme
Research around Vladimir Khavinson in St. Petersburg on peptide extracts from tissues and short synthetic peptides.
Lyophilisate
Freeze-dried powder. Without water a peptide keeps much longer.
Subcutaneous
Into the fat layer just under the skin.
T cells
White blood cells that recognise infected cells and steer the immune response.
Thymus
A gland behind the breastbone where T cells of the immune system mature. It shrinks with age.

Evidence

Sources

Show all 8 sourcesHide sources 4 Studies2 Trial registry2 Database checked 26 Oct 2026

Studies

  1. Thymalin added to standard care in COVID-19

    Khavinson et al., Stem Cell Reviews and Reports, 2021

    DOI 10.1007/s12015-020-10087-6 PMID 33575961
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed, PMC (Volltext)
  2. Thymalin and the maturation of human blood stem cells (cell culture)

    Khavinson et al., Bulletin of Experimental Biology and Medicine, 2020

    DOI 10.1007/s10517-020-05016-z PMID 33237528
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  3. The dipeptides KE and EW as active substances of Thymalin

    Linkova et al., International Journal of Molecular Sciences, 2023

    DOI 10.3390/ijms241713377 PMID 37686182
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  4. Natural and synthetic thymic peptides as immune therapeutics

    Morozov und Khavinson, International Journal of Immunopharmacology, 1997

    DOI 10.1016/s0192-0561(97)00058-1 PMID 9637345
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed

Trial registry

  1. Search on the WHO portal ICTRP (all partner registries, Thymalin, Тималин: no trial)

    WHO International Clinical Trials Registry Platform, Suche vom 26.10.2026

    Checked 26 Oct 2026 via WHO ICTRP
  2. Search on ClinicalTrials.gov (no trial with Thymalin)

    ClinicalTrials.gov, U.S. National Library of Medicine

    Checked 26 Oct 2026 via ClinicalTrials.gov API v2

Database

  1. Review of peptides and ageing from the Khavinson programme (PubMed record)

    Khavinson, Neuro Endocrinology Letters, 2002 (ohne DOI)

    PMID 12374906
    Checked 26 Oct 2026 via PubMed
  2. Thymalin and Epithalamin in 266 older adults over 6 to 8 years (PubMed record)

    Khavinson und Morozov, Neuro Endocrinology Letters, 2003 (ohne DOI)

    PMID 14523363
    Checked 26 Oct 2026 via PubMed

In the shop

Thymalin in the catalog

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