MEDICAL DISCLAIMER: Educational research guidelines only. Lyophilized peptides are investigational chemical compounds and are NOT approved for human consumption, diagnosis, or therapy. Consult a licensed physician before any research application.
Thymalin Dosage Chart, Schedule & Reconstitution Protocol
Quickstart Highlights
Thymalin is a thymic peptide bioregulator: a polypeptide complex extracted from calf thymus by Morozov and Khavinson that restores T-cell immunity. It is a mixture of short acidic peptides (~1-10 kDa) whose active fragments include the dipeptides KE (Lys-Glu) and EW (Glu-Trp) and the tripeptide EDP. It stimulates maturation of precursors into CD28+ T lymphocytes, normalizes the CD4/CD8 ratio, raises NK activity, and lowers IL-6 and TNF-α, with its short peptides proposed to bind DNA and histones to regulate immune-gene expression (PMC7686446, PMC10488166). A 2021 trial using 10 mg/day intramuscularly for 10 days reported halved hospital mortality in severe elderly COVID-19 patients (PMC8654498). Clinically Thymalin is given IM as a 5-10 day course repeated every 1-6 months; the subcutaneous figures here are an educational reconstitution reference. Reconstitute a 10 mg vial with 1 mL bacteriostatic water (10 mg/mL) so a 10 mg dose is 100 units on a U-100 syringe. It is prescription-only in Russia and not FDA or EMA approved.
Reconstitute: Add 1 mL bacteriostatic water → 10 mg/mL concentration.
Typical dose: 10 mg/day IM (5-10 day course)
Easy measuring: At 10 mg/mL, 1 unit = 0.01 mL = 0.1 mg (100 mcg) on a U-100 insulin syringe.
Storage: Lyophilized ampoule: store refrigerated at 2-8 °C, protected from light; research vials are often kept frozen at -20 °C for long-term storage. Clinically the powder is dissolved in sterile 0.9% saline immediately before injection and used at once; a reconstituted research vial should be kept refrigerated at 2-8 °C and used within about 3-4 weeks.
Half-life: Not formally characterized; as a mix of short peptides the intact molecules are likely cleared within minutes to about an hour, with durable effects attributed to downstream immune-gene-expression and T-cell differentiation changes.
Route: Clinically intramuscular (a 10 mg ampoule dissolved in 1-2 mL sterile 0.9% saline) once daily for 5-10 days; this page models a subcutaneous bacteriostatic-water reconstitution reference instead.
Status: Registered prescription drug in Russia and some post-Soviet states; NOT FDA or EMA approved and sold only for research use in the US and EU.
About Thymalin
Thymalin is a thymic peptide bioregulator: a polypeptide complex extracted from calf thymus that is used in Russian medicine to restore immune competence in immunodeficiency, chronic infections, and recovery after chemotherapy or radiation [1][6]. Clinically it is supplied as a 10 mg lyophilized ampoule dissolved in 1-2 mL of sterile 0.9% sodium chloride and injected INTRAMUSCULARLY once daily for a short 5-10 day course; the subcutaneous, bacteriostatic-water figures below are an educational reconstitution reference modeled on that ampoule, not the validated clinical route.\n\nThe most-cited Thymalin dosage is 10 mg per day for 5-10 days (range about 5-20 mg/day), with courses typically repeated after 1-6 months. The published COVID-19 study that reported halved hospital mortality used exactly 10 mg/day for 10 days [1].\n\nReconstituting a 10 mg vial with 1 mL of bacteriostatic water yields 10 mg/mL, so a 5 mg dose is 50 units (0.5 mL) and the standard 10 mg dose is 100 units (1.0 mL, one full vial) on a U-100 insulin syringe.\n\nFrequency: Inject once daily during a short 5-10 day course, then pause; courses are usually repeated every 1-6 months. Thymalin is a prescription drug in Russia but is not FDA- or EMA-approved, and this page is educational only.
Quick Protocol Navigation
Reconstitution Instruction & Mixing Step-by-Step
Lyophilized powder must be reconstituted carefully. Agitating peptide chains can shear disulfide bonds and render the peptide biologically inert.
Draw 1 mL of bacteriostatic water into a sterile syringe (clinically Thymalin is dissolved in sterile 0.9% saline; bacteriostatic water is used here as the site's reconstitution convention).
Inject the water slowly down the inner wall of the 10 mg Thymalin ampoule or vial; do not spray it directly onto the lyophilized powder.
Swirl or roll the vial gently until the powder fully dissolves into a clear, colorless solution; never shake, which can shear the peptides and cause foaming.
The result is 10 mg/mL, so 5 mg is 50 units (0.5 mL) and the standard 10 mg dose is 100 units (1.0 mL, the whole vial) on a U-100 insulin syringe; swab the stopper and draw the prescribed dose.
Educational note: clinically Thymalin is injected INTRAMUSCULARLY once daily during a 5-10 day course; for this subcutaneous modeling reference, inject slowly, store the vial refrigerated at 2-8 °C between uses, and discard after its stability window.
Interactive Thymalin Syringe Calculator
Currently visualizing the 10 mg vial reconstituted with 1 mL bacteriostatic water. Adjust the target dose to dynamically render syringe units.
Reconstitution Calculation: 10mg dry powder in 1mL water yields 10.00 mg/mL. To evaluate a 250mcg dose, pull to 2.5 units (3 syringe ticks).
U-100 Syringe Representation
Educational reference visual. Assumes standard U-100 insulin syringe where 1.0 mL volume = 100 units.
Titration & Dose Escalation Schedules
| Phase | Dose per injection | Units (per injection) |
|---|---|---|
| Low / maintenance course (days 1-10) | 2500 mcg (2.5 mg) | 25 units (0.25 mL) |
| Conservative course (days 1-10) | 5000 mcg (5 mg) | 50 units (0.50 mL) |
| Standard clinical course (days 1-10) | 10000 mcg (10 mg) | 100 units (1.00 mL) |
Administration guidelines: Refer to guidelines | 1 mL Reconstitution
Research Supplies Quantity Planner
Scientific mathematical planning of syringes, bacteriostatic water and dry vials needed for extended research blocks using the 10 mg vial.
Peptide Vials (Thymalin, 10 mg each):
- checkAt the standard 10 mg/day, each daily injection uses one full 10 mg vial, so a 5-10 day course needs about 5-10 vials (a 5 mg/day course uses roughly half a vial per injection).
- check8-week window (about 1 short course): roughly 10 vials.
- check12-week window (about 1-2 courses): roughly 10-20 vials.
- check16-week window (about 2 courses): roughly 20 vials.
Insulin Syringes (U-100):
- checkOne 1 mL (100-unit) syringe per daily injection, about 10 per 10-day course.
- check8-week window: roughly 10 syringes.
- check12-week window: roughly 10-20 syringes.
- check16-week window: roughly 20 syringes.
Bacteriostatic Water (30 mL bottles): Use 1 mL per 10 mg vial for reconstitution.
- checkEach reconstituted 10 mg vial uses 1 mL, so a 10-day standard course consumes about 10 mL (clinically, sterile 0.9% saline is used instead of bacteriostatic water).
- check8-week window: about 10 mL; 16-week window: about 20 mL.
- checkA single 30 mL bottle comfortably covers a course or two; discard any vial past its stability window rather than over-diluting to extend it.
Alcohol Swabs: clean the vial stopper and injection site before each use.
- checkUse 2 swabs per injection (vial top plus skin), about 20 per 10-day course.
- check8-week window: about 20 swabs; 12-week window: about 20-40 swabs; 16-week window: about 40 swabs.
- checkA single 100-count box comfortably covers a full year of seasonal courses.
Mechanism of Action (MOA)
Thymalin is not a single peptide but a standardized polypeptide complex extracted from the thymus of young calves, first prepared by Morozov and Khavinson using a method for isolating low-molecular-weight peptide fractions from young animal tissue [2][6]. It contains a heterogeneous family of short, acidic peptides with molecular weights spanning roughly 1-10 kDa; later work identified its minimal biologically active fragments as the dipeptides KE (Lys-Glu, the basis of the drug Vilon) and EW (Glu-Trp, the basis of the drug Thymogen) and the tripeptide EDP [4][6]. These are the same class of ultra-short peptides studied across Khavinson's bioregulator program.\n\nFunctionally, Thymalin is an immunomodulator that acts mainly on the T-cell arm of immunity. It stimulates maturation of thymic and bone-marrow precursors into mature T lymphocytes, normalizes the CD4/CD8 (helper/suppressor) ratio toward balance, increases natural-killer-cell activity, and modulates cytokine output. A 2020 study showed Thymalin reduced the stem-cell markers CD44 and CD117 by 2-3 fold while increasing the mature-T-cell marker CD28 about 6.8-fold in human hematopoietic stem cells, indicating it pushes immature CD117+ cells toward mature CD28+ T lymphocytes [3]. In peripheral-blood mononuclear cells, Thymalin and its KE and EW dipeptides cut synthesis of IL-1β, IL-6, and TNF-α by roughly 1.4-6 fold, the basis for its proposed suppression of the COVID-19 cytokine storm [4].\n\nAt the molecular level, the prevailing Khavinson hypothesis is that these short, charged peptides are small enough to enter the cell nucleus, where they bind specific sequences in gene-promoter regions and interact with histones and single- and double-stranded DNA, switching tissue-appropriate immune genes on or off [4][5]. Fluorescence-labeled Khavinson peptides have been shown to penetrate the nucleus and nucleolus of cultured cells and bind defined DNA oligonucleotides in vitro, lending experimental plausibility to this epigenetic-style gene-regulation model [8]. In this framework Thymalin behaves less like a hormone supplying a signal and more like a regulator that restores a youthful pattern of immune-gene expression [5].\n\nPharmacokinetics have not been formally characterized in modern peer-reviewed studies, and the precise half-life figures quoted by supplement vendors are not supported by primary data. As a mixture of unmodified short peptides, Thymalin's components are expected to be hydrolyzed rapidly by plasma and tissue peptidases, giving a free-peptide plasma half-life on the order of minutes to perhaps an hour; the clinical rationale for short daily courses rather than continuous dosing is that the durable effect is attributed to downstream changes in immune-gene expression and cell differentiation that outlast the peptides themselves [5][6]. Oral bioavailability of such peptides is low because of gastrointestinal proteolysis, which is why Thymalin is given parenterally.\n\nClinically and historically Thymalin is delivered by deep intramuscular injection, with each 10 mg ampoule dissolved in 1-2 mL of sterile 0.9% saline immediately before use; the once-daily subcutaneous reconstitution with bacteriostatic water described on this page is an educational modeling convention used across this site, not a route validated for Thymalin. The drug is registered and prescribed in Russia and several neighboring countries but holds no FDA or EMA approval, so elsewhere it should be treated as a research compound and the dosing here as reference information only [1][6].
Clinical Trial Efficacy Highlights
- starIn a 2021 controlled study (Kuznik and colleagues, Advances in Gerontology), severe COVID-19 patients given Thymalin 10 mg/day intramuscularly for 10 days plus standard care (n=36) had roughly halved hospital mortality versus standard care alone (19.4% vs 40.9%, n=44), with faster clinical improvement (80.5% vs 59%), an approximately 6.5-fold drop in IL-6, a 3.3-fold fall in C-reactive protein, lower D-dimer, and about a 2.2-fold rise in total T-, CD4+, and CD8+ lymphocytes alongside doubled NK cells [1].
- starIn the landmark long-term geroprotection trial (Khavinson and Morozov, Neuroendocrinology Letters 2003), 266 elderly people followed for 6-8 years showed a 2.0-2.1-fold reduction in mortality with Thymalin and a 2.0-2.4-fold reduction in acute respiratory disease incidence; combining Thymalin with the pineal peptide epithalamin annually for 6 years reduced mortality about 4.1-fold versus controls [2].
- starA 2020 study in Bulletin of Experimental Biology and Medicine reported that Thymalin reduced the stem-cell markers CD44 and CD117 by 2-3 fold and increased the mature-T-cell marker CD28 about 6.8-fold in human hematopoietic stem cells, evidence that it drives differentiation of immature CD117+ cells into mature CD28+ T lymphocytes [3].
- starA 2023 mechanistic paper in the International Journal of Molecular Sciences showed that Thymalin and its KE and EW dipeptides lowered IL-1β, IL-6, and TNF-α synthesis in human peripheral-blood mononuclear cells by 1.4-6 fold; KE activated macrophages, lymphocytes, thymocytes, and neutrophils, while EW reduced angiotensin-driven vasoconstriction and preserved endothelial function relevant to severe COVID-19 [4].
- starA 2021 systematic review in Molecules (Khavinson and colleagues) summarized how short 2-7 amino-acid peptides, including the fragments found in Thymalin, regulate gene expression by penetrating the nucleus and binding DNA and histone proteins; it provides the mechanistic rationale but is a review rather than a Thymalin efficacy trial [5].
- starA 2021 review in Biology Bulletin Reviews catalogues decades of Russian clinical and experimental use of Thymalin for immune dysfunction, viral and bacterial infections, regeneration, and immunodepression after chemotherapy or radiotherapy, while making clear that this large body of work originates largely from a single research lineage and has limited independent Western replication [6].
- starKhavinson's foundational 'Peptides and Ageing' monograph (Neuroendocrinology Letters 2002) lays out the tissue-specific bioregulator framework under which Thymalin was designed, presenting it as a thymus-targeted immune geroprotector but acknowledging that much of the supporting evidence predates modern randomized-trial standards [7].
- starIn vitro work by Fedoreyeva and colleagues (2011) demonstrated that short fluorescence-labeled Khavinson peptides penetrate the cytoplasm, nucleus, and nucleolus of cultured cells and bind specific DNA oligonucleotides, giving experimental support to the nuclear gene-regulation mechanism proposed for Thymalin's active fragments [8].
Side Effects & Tolerability Profile
Clinical subjects transiently report mild side effects. Slowly escalating the titration dose represents the single most effective intervention to limit side effects.
- warningIn Russian clinical use Thymalin is generally described as well tolerated; the most commonly reported reaction is local pain, redness, or induration at the intramuscular injection site.
- warningHypersensitivity is the principal labeled contraindication: as a foreign, bovine-derived protein complex it can provoke rash, itching, or, rarely, systemic allergic reactions, and individual intolerance is a contraindication to use.
- warningBecause it is derived from animal thymus tissue, theoretical risks include immunogenicity and, for non-pharmaceutical material, transmissible-agent or endotoxin contamination; research-grade vials are not manufactured to drug-quality standards, so sterility and purity cannot be assumed.
- warningAs an immunomodulator it is generally avoided in pregnancy and breastfeeding, is not established for self-directed use in children, and is theoretically risky in autoimmune disease, where altering T-cell balance could worsen the condition.
- warningSubcutaneous injection (the modeling route on this page) can cause redness, swelling, bruising, or transient pain; the clinically validated route is deep intramuscular injection, not subcutaneous.
- warningNo formal drug-interaction studies exist; people taking immunosuppressants, biologics, corticosteroids, or other medications should not assume Thymalin is inert or compatible.
- warningThe strongest efficacy data come largely from a single Russian research lineage with limited independent Western replication, so both the magnitude of benefit and long-term safety remain incompletely characterized.
- warningRegulatory status: Thymalin is a registered prescription drug in Russia and some post-Soviet states but is NOT approved by the FDA or EMA; in the US and EU it is sold only for laboratory research and is neither a medicine nor a dietary supplement.
Subcutaneous Injection Technique
Most research peptides require subcutaneous injection into fatty tissue. Never inject directly into a blood vessel or deep muscle tissue unless clinically detailed.
1. Site Selection
Common locations include the abdomen (2 inches from navel), outer upper arms, or thighs.
2. Sanitization
Thoroughly clean the selected site, stopper and vial top using 70% isopropyl alcohol prep swabs.
3. Angle & Push
Pinch the skin and insert the needle at a 45 to 90-degree angle. Depress plunger smoothly.
4. Site Rotation
Rotate injection sites continuously to avoid lipodystrophy or tissue scarring.
Frequently Asked Questions
What is the typical Thymalin dosage?expand_more
The most commonly cited Thymalin dosage is about 10 mg per day given by intramuscular injection for a short course of 5-10 days, with the range in the Russian clinical literature running roughly 5-20 mg/day. Each 10 mg lyophilized ampoule is dissolved in 1-2 mL of sterile 0.9% saline immediately before injection, and courses are usually repeated only after a 1-6 month gap. The published severe-COVID-19 trial that reported halved hospital mortality used exactly 10 mg/day for 10 days. Treat these as reference figures from outside the US/EU regulatory system, not a personal recommendation, because there is no FDA- or EMA-approved Thymalin dose.
Is Thymalin FDA approved?expand_more
No. Thymalin is not approved by the FDA, the EMA, or any major Western regulator. It is, however, a registered prescription drug in Russia and several post-Soviet states, where it has been used since the 1980s as a thymic immunomodulator. In the United States and the European Union it is treated as an unapproved research compound, is not a dietary supplement, and is sold only for laboratory use. Nothing on this page should be read as a claim that Thymalin is safe or effective for treating any condition.
How do you reconstitute Thymalin?expand_more
On this educational reference, draw 1 mL of bacteriostatic water and inject it slowly down the inner wall of a 10 mg Thymalin vial, then swirl gently (never shake) until the powder dissolves into a clear solution. That gives 10 mg/mL, so 5 mg is 50 units (0.5 mL) and the standard 10 mg dose is 100 units (1.0 mL, the whole vial) on a U-100 insulin syringe. Note that clinically Thymalin is reconstituted instead in sterile 0.9% saline and injected intramuscularly, and the ampoule is typically dissolved fresh and used immediately rather than stored.
What is Thymalin's half-life?expand_more
Thymalin's half-life has not been formally characterized in published pharmacokinetic studies, and the precise numbers quoted on vendor sites are not supported by primary data. Because it is a mixture of unmodified short peptides, the intact fragments are expected to be broken down rapidly by plasma and tissue peptidases, giving a free-peptide plasma half-life on the order of minutes to perhaps an hour. The Khavinson framework attributes Thymalin's longer-lasting effect to downstream changes in immune-gene expression and T-cell differentiation that outlast the peptides, which is why it is dosed in short daily courses rather than continuously.
Can Thymalin be stacked with other Khavinson bioregulators?expand_more
In the Russian bioregulator literature, Thymalin is frequently combined with tissue-specific peptides such as the pineal peptide epithalamin; the 6-8 year geroprotection study in fact paired the two and reported the largest mortality reduction with annual combined courses. It is also marketed alongside related thymic peptides like Thymogen (EW) and Vilon (KE). However, there are no controlled data on the safety, interactions, or added benefit of combining unapproved research peptides, and stacking multiplies the unknown risks. This is general information, not medical advice; anyone considering these compounds should consult a qualified clinician.
Related Guides & Tools
Step-by-step references for reconstituting, measuring, and storing Thymalin, plus the universal dosing calculator.
Academic References & Study Citations
Kuznik BI, Khavinson VKh, Shapovalov KG, et al. Peptide Drug Thymalin Regulates Immune Status in Severe COVID-19 Older Patients. Advances in Gerontology. 2021;11(4):368-376. View Scientific Paper →
Khavinson VKh, Morozov VG. Peptides of pineal gland and thymus prolong human life. Neuro Endocrinol Lett. 2003;24(3-4):233-240. View Scientific Paper →
Khavinson VKh, Linkova NS, Kvetnoy IM, Polyakova VO, Drobintseva AO, Kvetnaia TV, Ivko OM. Thymalin: Activation of Differentiation of Human Hematopoietic Stem Cells. Bull Exp Biol Med. 2020;170(1):124-127. View Scientific Paper →
Khavinson V, Linkova N, Kozhevnikova E, et al. The Influence of KE and EW Dipeptides in the Composition of the Thymalin Drug on Gene Expression and Protein Synthesis Involved in the Pathogenesis of COVID-19. Int J Mol Sci. 2023;24(17):13377. View Scientific Paper →
Khavinson VKh, Popovich IG, Linkova NS, Mironova ES, Ilina AR. Peptide Regulation of Gene Expression: A Systematic Review. Molecules. 2021;26(22):7053. View Scientific Paper →
Khavinson VKh, et al. The Use of Thymalin for Immunocorrection and Molecular Aspects of Biological Activity. Biology Bulletin Reviews. 2021;11(4). doi:10.1134/S2079086421040046. View Scientific Paper →
Khavinson VKh. Peptides and Ageing. Neuro Endocrinol Lett. 2002;23 Suppl 3:11-144. View Scientific Paper →
Fedoreyeva LI, Kireev II, Khavinson VKh, Vanyushin BF. Penetration of short fluorescence-labeled peptides into the nucleus in HeLa cells and in vitro specific interaction of the peptides with deoxyribooligonucleotides and DNA. Biochemistry (Mosc). 2011;76(11):1210-1219. View Scientific Paper →