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Research information only. Not medical advice. 18+ only. Not FDA-approved for human therapeutic use.

Thymalin

Also known as: thymic polypeptide extract, thymus polypeptide factor, thymic factor, cytomedin (thymus), thymus peptide complex

Polypeptide complex / thymic immunomodulator (extracted from mammalian thymus gland)

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What it is

Thymalin is a polypeptide complex isolated from the thymus gland that regulates immune system function. Its active components include the KE and EW dipeptides. KE stimulates cellular immunity and nonspecific resistance, activating macrophages, blood lymphocytes, thymocytes, and neutrophils; EW reduces angiotensin-induced vasoconstriction and preserves endothelium-dependent vascular relaxation by inhibiting ACE2. Thymalin reduces expression of CD44 and CD117 (stem cell and intermediate differentiation markers) and increases CD28 expression (marker of mature T lymphocytes) by 6.8-fold, suggesting stimulation of hematopoietic stem cell differentiation into mature T lymphocytes. KE and EW dipeptides interact with double-stranded DNA, potentially regulating gene expression of proteins including AKT1 and AKT2 involved in cytokine storm development; in vitro, Thymalin and its dipeptide components reduce synthesis of IL-1β, IL-6, and TNF-α in human peripheral blood mononuclear cells by 1.4–6.0 times under inflammatory conditions. Thymalin also normalizes the LDH isoenzyme spectrum and cyclase system in lymphocytes and contributes to expression of differentiation antigens on T-lymphocyte surfaces. In the monocyte/macrophage THP-1 cell line, the Thymalin peptide complex modulates key proliferative patterns, increases tyrosine phosphorylation of mitogen-activated cytoplasmic kinases, and inhibits TNF and IL-6 expression stimulated by LPS. Thymalin was also found to be present endogenously in human thymic epithelium, airway epithelium, and epidermis, with levels declining with age (PMID 36169363, PMID 12937685, PMID 12447484).

Class: Polypeptide complex / thymic immunomodulator (extracted from mammalian thymus gland)

What it's studied for

  • COVID-19 (severe) — immunomodulation and reduction of cytokine storm Human observational
    • In a retrospective study of severe COVID-19 patients (middle-aged and elderly), Thymalin (added to basic therapy) was associated with hospital mortality of 20.6% vs 40.9% in the standard-therapy control group. Thymalin increased lymphocyte and monocyte counts by 2-fold and leukocyte count by 1.3-fold, decreased fibrino PMID 36169363 Kuznik et al., Advances in gerontology, 2022
    • Thymalin and its active KE and EW dipeptides reduced synthesis of IL-1β, IL-6, and TNF-α in LPS-stimulated human peripheral blood mononuclear cells by 1.4–6.0 times in vitro. Molecular docking and bioinformatics identified potential regulatory targets in COVID-19 cytokine storm pathways. PMID 37686182 Linkova et al., International Journal of Molecular Sciences, 2023
    • Thymalin reduced CD44 and CD117 expression by 2–3-fold and increased CD28 expression by 6.8-fold in cultured human hematopoietic stem cells, suggesting stimulation of T-lymphocyte differentiation relevant to COVID-19 immunity. PMID 33237528 Khavinson et al., Bulletin of Experimental Biology and Medicine, 2020
  • Geroprotection / longevity in elderly individuals Human RCT
    • In a clinical trial of 266 elderly and older persons followed for 6–8 years (bioregulators applied during the first 2–3 years), Thymalin-treated group showed 2.0–2.1-fold decreased mortality. Combined Thymalin + Epithalamin annual treatment over 6 years showed 4.1-fold mortality decrease vs control. Improvements seen i PMID 14523363 Khavinson & Morozov, Neuro Endocrinology Letters, 2003
    • Corroborating data from the same 266-person, 6–8-year observation: Thymalin-treated group had 2.0–2.1-fold reduction in mortality; Thymalin + Epithalamin group had 2.5-fold reduction; combined annual regimen for 6 years showed 4.1-fold reduction. PMID 12577695 Khavinson & Morozov, Advances in gerontology, 2002
  • Immunomodulation in inflammatory and infectious diseases Human observational
    • Thymalin treatment in 32 burn patients (III–IV degree) promoted resolution of disseminated intravascular coagulation, normalized fibrinolysis, influenced pro- and anti-inflammatory cytokines, shortened first autodermoplasty by ~5 days, and reduced hospital stay by 11 days. PMID 11188814 Kuznik et al., Vestnik khirurgii, 2000
    • Differential administration of thymalin combined with chemotherapy in 60 cases of destructive pulmonary tuberculosis greatly shortened hospital stay and increased treatment efficacy, with normalizing influence on immune system recovery. PMID 2080155 Kogosova et al., Problemy tuberkuleza, 1990
    • Thymalin (5 ml, 4–6 injections per course) added to standard treatment in 21 of 35 patients with non-specific pulmonary diseases corrected decreased cellular immunity characteristics and normalized lymphocyte count and OKT-4+/OKT-8+ subpopulations. PMID 2741122 Dovnar et al., Terapevticheskii arkhiv, 1989
  • Oncology — immunocorrection as adjunct to cancer treatment Human observational
    • In 38 advanced cervical carcinoma patients, radiation supplemented with thymalin immunotherapy showed clear advantage over radiotherapy alone (control n=58), allowing wider application of radical surgery and better results in previously considered incurable patients. PMID 2014686 Vishnevskaya et al., Voprosy onkologii, 1991
    • 35 of 111 endometrial cancer patients received Thymalin as part of complex treatment (hormonotherapy + surgery); positive effects on cell immunity and clinico-morphological parameters were registered. PMID 2245808 Bakhidze & Bokhman, European Journal of Gynaecological Oncology, 1990
    • Inclusion of thymalin (with or without plasmapheresis) in treatment of chronic lymphoid leukemia patients improved functional activity of lymphoid cells and reduced time to clinico-hematological remission compared to chemotherapy alone. PMID 9670669 Tretiak et al., Likars'ka sprava, 1998
  • Reparative osteogenesis / bone defect healing Animal studies only
    • In 48 WAG rats with simulated mandibular bone defects, combined use of hydroxyapatite-containing bone graft (Biomin GT) + thymalin soft-tissue injection significantly stimulated reparative osteogenesis vs either treatment alone or untreated control, with accelerated clearance of necrotic tissue, modulation of immune ce PMID 38431810 Boiko et al., Wiadomosci lekarskie, 2024
  • In vitro immunomodulation of monocyte/macrophage inflammatory pathways In vitro only
    • In THP-1 human monocytic cells, the Thymalin peptide complex increased tyrosine phosphorylation of mitogen-activated cytoplasmic kinases, inhibited TNF and IL-6 expression stimulated by LPS in terminally differentiated macrophages, and reduced adhesion to LPS-activated endothelial cells. PMID 35408963 Avolio et al., International Journal of Molecular Sciences, 2022
  • Ischemic heart disease — adjunct therapy Human observational
    • Thymalin in multimodality therapy of CHD patients with angina pectoris normalized cellular and humoral immunity, slowed blood coagulation, decreased fibrinogen and FDP concentration, and enhanced fibrinolysis. More rapid disappearance of pain syndrome observed vs patients not receiving the drug. PMID 3488603 Kuznik et al., Terapevticheskii arkhiv, 1986
    • In 156 patients with exertion stenocardia (II–IV functional class), complex treatment including thymalin resulted in increased thymic factor levels, normalization of lipid metabolism, and increased contractile function of the myocardium. PMID 1481512 Shustval', Likars'ka sprava, 1992
  • Multiple sclerosis — homeostatic correction Human observational
    • Arginine-vasopressin combined with thymalin was found advisable for correction of homeostatic abnormalities and secondary disease prophylaxis in multiple sclerosis patients. Thymalin sensitivity of lymphocytes was studied. PMID 2160161 Akimov et al., Zhurnal nevropatologii i psikhiatrii, 1990
  • Therapy-resistant schizophrenia — adjunct immunomodulation Human observational
    • Thymalin combined with psychotropic drugs in 36 therapeutically resistant schizophrenia patients with pronounced immune abnormalities led to considerable enhancement of treatment efficacy: elimination or amelioration of psychic disorders, activation of patients, and reduction of neuroleptic complications. Positive clin PMID 2163147 Govorin & Stupina, Zhurnal nevropatologii i psikhiatrii, 1990
  • Herpetic infections (ophthalmic herpes, herpetic stomatitis) Human observational
    • Therapeutic efficacies of thymalin and T-activin were assessed in 80 patients with ophthalmic herpes; thymic hormone preparations were recommended for treatment of protracted conditions. PMID 1763455 Mal'khanov et al., Vestnik oftalmologii, 1991
    • Thymalin (polypeptide drug from cattle thymus) used in 44 children with acute and relapsing herpetic stomatitis; did not accelerate acute symptom abatement but achieved a stable anti-relapse effect in children at high risk of recurrences. PMID 8191521 Kazantseva & Bikbulatov, Stomatologiia, 1994
  • Psoriasis — immunomodulation and hemostasis normalization Human observational
    • Use of thymalin in combined therapy of disseminated psoriasis patients resulted in complete or incomplete normalization of immunity and hemostasis parameters, paralleled by clinical improvement. PMID 2609748 Isaeva et al., Vestnik dermatologii i venerologii, 1989
  • Parkinson's disease — adjunct therapy Human observational
    • Fifteen patients (ages 45–72) with idiopathic parkinsonism (stages 1B–2A) treated with thymalin showed positive course in general well-being, parkinsonian triad symptoms, and cerebral integrative function. EEG mapping confirmed significant decrement in alpha rhythm power in anterocentral brain regions, suggesting impro PMID 10424021 Musienko, Likars'ka sprava, 1999
  • Radiation protection / modification of radiation-induced cytogenetic effects Human observational
    • Thymalin (along with inosine, ascorbic acid, and caffeine) was found to modify radiation-induced cytogenetic effects in peripheral blood lymphocytes of healthy individuals, with protective or sensitizing action depending on concentrations, cell radiosensitivity, dose of irradiation, and relative biological effectivenes PMID 28230819 Domina, Experimental Oncology, 2016
  • Peritonitis — adjunct treatment Human observational
    • In 63 patients with acute peritonitis, thymalin used alone or combined with heparin facilitated quicker arrest of the pathological process. Combination of thymalin and heparin indicated for elderly patients and those with higher risk of thrombus formation. PMID 3754668 Kokotov et al., Vestnik khirurgii, 1986
  • Diabetes mellitus in children — adjunct immunotherapy Human observational
    • Clinico-metabolic investigations demonstrated efficacy of thymalin in multimodality therapy of diabetes mellitus in children. PMID 2695919 Kurbanov et al., Problemy endokrinologii, 1989
  • Endogenous thymalin — presence in fetal/adult tissues (basic science) In vitro only
    • Thymalin was found in young cells of airway epithelium during early embryogenesis; thymalin-positive cells diffusely spread in alveolar part; mature T cells (CD3+, CD4+, CD8+) detected in fetal lungs independent of thymic microenvironment. PMID 12937685 Khlystova et al., Bulletin of Experimental Biology and Medicine, 2003
    • Thymalin present in human epidermis and fetal reticuloepithelium (both derived from ectoderm); present only in young epidermal cells; content decreases with age, with thinned and discontinuous thymalin-containing layer by age 70. PMID 12447484 Khlystova et al., Bulletin of Experimental Biology and Medicine, 2002

Community-reported dosing

RouteDoseFrequency / DurationPopulation / contextSource tier
Not specified (described as 'administration')5 ml, 4–6 injections per treatment courseSingle course (number of days not specified)humanResearch PMID 2741122
Soft tissue injection (perilesional)Not specified (injected into surrounding soft tissues of mandibular bone defect)Not specifiedanimalResearch PMID 38431810
Intraosseous (intraosteal lavage)Not stated in abstractNot stated in abstracthumanResearch PMID 2029618
subcutaneous injection10 mgdailybiohackers and longevity-focused adults seeking immune system restoration and anti-aging effects[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection10 mgdailyanti-aging biohackers stacking with Epithalon or other Khavinson peptides[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection5 mgdailybiohackers new to Thymalin or those preferring a conservative starting dose[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection10 mgdailyolder adults (50+) and longevity-focused biohackers on a less aggressive maintenance schedule[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection10 mgdailylongevity biohackers running combined Khavinson peptide protocols[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection20 mgdailybiohackers seeking a compressed high-dose course, often due to scheduling constraints[S] Claude Sonnet 4.6 — synthesized from aggregate training data

Tier key: Research = PMID-cited study · [C] = scraped community source · [S] = model-synthesized from aggregate community reports (softer evidence). How we source.

Safety signals

  • No systematic adverse event data reported across the reviewed abstracts; no serious adverse events explicitly attributed to Thymalin were described in any of the available study reports. PMID 38431810
  • Thymalin was noted to not accelerate acute symptom abatement in herpetic stomatitis, suggesting possible limitations in acute anti-infective efficacy rather than a direct safety signal. PMID 8191521
  • In dysentery patients, thymalin (unlike indomethacin) did not accelerate normalization of nonspecific lymphocyte adhesiveness and appeared to inhibit antigen-specific T-lymphocyte adhesiveness compared to indomethacin, suggesting differential immunological effects. PMID 2441548
  • Thymalin did not exert substantial effect on chemotaxis and phagocytosis of leukocytes, content of immunoglobulins, or circulating immune complexes in pulmonary disease patients, indicating selective rather than broad immune effects. PMID 2741122

Contraindications

  • No explicit contraindications are stated in the reviewed abstracts. Use in immunocompromised patients (e.g., AIDS) was described as a study population rather than a contraindicated group; formal contraindications are not established in this literature. PMID 2382426

Frequently asked

What is Thymalin and where does it come from?

Thymalin is a polypeptide complex isolated from the thymus gland (described as extracted from cattle thymus in at least one study, PMID 8191521). It is classified as a thymic immunomodulator. Its active components include the KE and EW dipeptides. Endogenous thymalin-like material has also been detected in human thymic epithelium, airway epithelium, and epidermis (PMID 12937685, PMID 12447484).

What has Thymalin been studied for?

Based on the reviewed published abstracts, Thymalin has been studied in a wide range of clinical and experimental contexts, including: severe COVID-19; geroprotection and longevity in elderly individuals; immune correction in cancer patients; burns; tuberculosis; ischemic heart disease; multiple sclerosis; Parkinson's disease; herpetic infections; psoriasis; peritonitis; diabetes mellitus in children; and bone defect healing in animals. Much of the clinical evidence comes from observational studies, many published in Russian-language journals.

What dose of Thymalin should I take?

I'm not a medical professional and can't recommend a protocol for you specifically. What research has shown: One observational study administered thymalin at 5 ml for 4–6 injections per treatment course in patients with non-specific pulmonary diseases. The geroprotection trials used the drug during the first 2–3 years of a 6–8-year observation period without specifying exact dose in the reviewed abstract. No standardized dosing regimen could be derived from the reviewed abstracts.

Is Thymalin approved by the FDA or other regulatory agencies?

The reviewed published abstracts do not explicitly state the regulatory status of Thymalin with the US FDA, Health Canada, or WADA. Manual verification with those regulatory bodies or a licensed healthcare provider is required.

How does Thymalin work at the molecular level?

Based on the reviewed abstracts: Thymalin's active KE and EW dipeptides interact with double-stranded DNA, potentially regulating gene expression of AKT1, AKT2, and other proteins involved in the cytokine storm. Thymalin reduces expression of CD44 and CD117 (stem cell markers) and increases CD28 (mature T-lymphocyte marker) expression by 6.8-fold in human hematopoietic stem cells. It also normalizes the LDH isoenzyme spectrum and cyclase system in lymphocytes and promotes expression of T-lymphocyte differentiation antigens. In THP-1 cells, it increases tyrosine phosphorylation of cytoplasmic kinases and inhibits LPS-stimulated TNF and IL-6 expression.

Was Thymalin studied for COVID-19?

Yes. A retrospective study of severe COVID-19 patients (middle-aged and elderly) found that Thymalin added to basic therapy was associated with hospital mortality of 20.6%, compared to 40.9% with standard therapy alone and 28.4% with Tocilizumab. Thymalin increased lymphocyte and monocyte counts and decreased fibrinogen, LDH, and D-dimer levels. In vitro, Thymalin and its KE and EW dipeptide components reduced IL-1β, IL-6, and TNF-α synthesis by 1.4–6.0-fold in LPS-stimulated human mononuclear cells. Thymalin also increased CD28 expression in human hematopoietic stem cells, which may be relevant given that CD28+ T-lymphocytes are depleted in severe COVID-19. These are observational and in vitro findings; no randomized controlled trial specifically for COVID-19 was identified in the reviewed abstracts.

Can Thymalin extend lifespan or slow aging?

A clinical study (described as a randomized controlled trial) followed 266 elderly persons over 6–8 years and reported that Thymalin-treated patients had a 2.0–2.1-fold reduction in mortality compared to controls; annual combined Thymalin + Epithalamin treatment over 6 years was associated with a 4.1-fold mortality reduction. Improvements were also reported in cardiovascular, endocrine, immune, and nervous system indices, and a 2.0–2.4-fold decrease in acute respiratory disease incidence. These findings are promising but come from a specific research group and context; independent replication in diverse populations is not documented in the reviewed abstracts.

What routes of administration have been reported in studies?

The reviewed abstracts report: intramuscular injection, subcutaneous injection, soft tissue (perilesional) injection, intraosseous/intraosteal lavage, and intralymphatic (endolymphatic) administration. The specific route for most other clinical studies was not detailed in the available abstract text.

Can I combine Thymalin with other peptides or drugs?

I can't recommend combining compounds — that's a prescribing decision. Here's what has been studied individually: Thymalin has been studied in combination with Epithalamin (pineal peptide bioregulator) in a geroprotection trial; with heparin in peritonitis; with arginine-vasopressin in multiple sclerosis; with standard chemotherapy in tuberculosis and leukemia; and with basic COVID-19 therapy. Each of these was studied in specific clinical contexts.

Are there any known safety concerns or side effects with Thymalin?

The reviewed abstracts do not report systematic adverse event data or formal safety monitoring for Thymalin. No serious adverse events explicitly attributed to Thymalin were described. One study noted Thymalin did not accelerate acute symptom resolution in herpetic stomatitis. Another found Thymalin had no substantial effect on chemotaxis, phagocytosis, immunoglobulins, or circulating immune complexes, suggesting selective immune effects. Thymalin is derived from bovine thymus; risks associated with animal-derived biologics such as contamination or batch variability are not discussed in the reviewed abstracts. Consult a licensed healthcare provider for individual safety assessment.

References

  1. [1] PMID 36169363 — In a retrospective study of severe COVID-19 patients (middle-aged and elderly), Thymalin (added to basic therapy) was associated with hospital mortality of 20.6
  2. [2] PMID 37686182 — Thymalin and its active KE and EW dipeptides reduced synthesis of IL-1β, IL-6, and TNF-α in LPS-stimulated human peripheral blood mononuclear cells by 1.4–6.0 t
  3. [3] PMID 33237528 — Thymalin reduced CD44 and CD117 expression by 2–3-fold and increased CD28 expression by 6.8-fold in cultured human hematopoietic stem cells, suggesting stimulat
  4. [4] PMID 14523363 — In a clinical trial of 266 elderly and older persons followed for 6–8 years (bioregulators applied during the first 2–3 years), Thymalin-treated group showed 2.
  5. [5] PMID 12577695 — Corroborating data from the same 266-person, 6–8-year observation: Thymalin-treated group had 2.0–2.1-fold reduction in mortality; Thymalin + Epithalamin group
  6. [6] PMID 11188814 — Thymalin treatment in 32 burn patients (III–IV degree) promoted resolution of disseminated intravascular coagulation, normalized fibrinolysis, influenced pro- a
  7. [7] PMID 2080155 — Differential administration of thymalin combined with chemotherapy in 60 cases of destructive pulmonary tuberculosis greatly shortened hospital stay and increas
  8. [8] PMID 2741122 — Thymalin (5 ml, 4–6 injections per course) added to standard treatment in 21 of 35 patients with non-specific pulmonary diseases corrected decreased cellular im
  9. [9] PMID 2014686 — In 38 advanced cervical carcinoma patients, radiation supplemented with thymalin immunotherapy showed clear advantage over radiotherapy alone (control n=58), al
  10. [10] PMID 2245808 — 35 of 111 endometrial cancer patients received Thymalin as part of complex treatment (hormonotherapy + surgery); positive effects on cell immunity and clinico-m
  11. [11] PMID 9670669 — Inclusion of thymalin (with or without plasmapheresis) in treatment of chronic lymphoid leukemia patients improved functional activity of lymphoid cells and red
  12. [12] PMID 38431810 — In 48 WAG rats with simulated mandibular bone defects, combined use of hydroxyapatite-containing bone graft (Biomin GT) + thymalin soft-tissue injection signifi
  13. [13] PMID 35408963 — In THP-1 human monocytic cells, the Thymalin peptide complex increased tyrosine phosphorylation of mitogen-activated cytoplasmic kinases, inhibited TNF and IL-6
  14. [14] PMID 3488603 — Thymalin in multimodality therapy of CHD patients with angina pectoris normalized cellular and humoral immunity, slowed blood coagulation, decreased fibrinogen
  15. [15] PMID 1481512 — In 156 patients with exertion stenocardia (II–IV functional class), complex treatment including thymalin resulted in increased thymic factor levels, normalizati
  16. [16] PMID 2160161 — Arginine-vasopressin combined with thymalin was found advisable for correction of homeostatic abnormalities and secondary disease prophylaxis in multiple sclero
  17. [17] PMID 2163147 — Thymalin combined with psychotropic drugs in 36 therapeutically resistant schizophrenia patients with pronounced immune abnormalities led to considerable enhanc
  18. [18] PMID 1763455 — Therapeutic efficacies of thymalin and T-activin were assessed in 80 patients with ophthalmic herpes; thymic hormone preparations were recommended for treatment
  19. [19] PMID 8191521 — Thymalin (polypeptide drug from cattle thymus) used in 44 children with acute and relapsing herpetic stomatitis; did not accelerate acute symptom abatement but
  20. [20] PMID 2609748 — Use of thymalin in combined therapy of disseminated psoriasis patients resulted in complete or incomplete normalization of immunity and hemostasis parameters, p
  21. [21] PMID 10424021 — Fifteen patients (ages 45–72) with idiopathic parkinsonism (stages 1B–2A) treated with thymalin showed positive course in general well-being, parkinsonian triad
  22. [22] PMID 28230819 — Thymalin (along with inosine, ascorbic acid, and caffeine) was found to modify radiation-induced cytogenetic effects in peripheral blood lymphocytes of healthy
  23. [23] PMID 3754668 — In 63 patients with acute peritonitis, thymalin used alone or combined with heparin facilitated quicker arrest of the pathological process. Combination of thyma
  24. [24] PMID 2695919 — Clinico-metabolic investigations demonstrated efficacy of thymalin in multimodality therapy of diabetes mellitus in children.
  25. [25] PMID 12937685 — Thymalin was found in young cells of airway epithelium during early embryogenesis; thymalin-positive cells diffusely spread in alveolar part; mature T cells (CD
  26. [26] PMID 12447484 — Thymalin present in human epidermis and fetal reticuloepithelium (both derived from ectoderm); present only in young epidermal cells; content decreases with age
  27. [27] PMID 2029618 — Not stated in abstract Intraosseous (intraosteal lavage) (human)
  28. [28] PMID 2441548 — In dysentery patients, thymalin (unlike indomethacin) did not accelerate normalization of nonspecific lymphocyte adhesiveness and appeared to inhibit antigen-sp
  29. [29] PMID 2382426 — No explicit contraindications are stated in the reviewed abstracts. Use in immunocompromised patients (e.g., AIDS) was described as a study population rather th
  30. [30] PMID 2326818 — in-prose reference
  31. [31] PMID 3754913 — in-prose reference
  32. [32] PMID 2750120 — in-prose reference
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