Thymalin
Calf Thymus Polypeptide Complex | Immune Reconstitution & Geroprotection
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What is Thymalin?
Thymalin is a polypeptide mixture extracted from calf thymus tissue, developed by Russian researchers and registered as a pharmaceutical in Russia since the 1980s. Published research — mostly from one research group — has studied its effects on immune-cell development and inflammation markers, including a small clinical trial in hospitalized patients. Thymalin is not FDA- or Health-Canada-approved, and research-grade material sold here is intended strictly for laboratory study, not human use.
Key terms:
Thymalin is a polypeptide complex from calf thymus tissue.
Thymalin is a polypeptide mix from calf thymus, developed in the 1970s by V.G. Morozov and V.Kh. Khavinson at St. Petersburg's Institute of Bioregulation and Gerontology. Russia registered it as a drug in 1982 (Samson-Med, Roszdravnadzor LS-000267). Unlike Thymulin, one nonapeptide, Thymalin is a mixture whose fragments sell separately: Glu-Trp (Thymogen), Lys-Glu (Vilon), Glu-Asp-Pro (Crystagen). Reported: faster T-cell maturation from CD117+ progenitors, restored B/T ratios, epigenetic shifts in TNF-alpha, IL-6, IL-1beta. Russian clinical use: immunodeficiency, immune recovery after radio- or chemotherapy, bronchial asthma, poor tissue repair. A 2021 open-label RCT (n=92) found lower inflammatory markers in hospitalized COVID-19 patients; a 6-8 year observational study (n=266) reported lower all-cause mortality in older adults. Nearly all evidence is Khavinson-group work; no independent Western replication.
Key research areas
- Immune reconstitution
- T-cell maturation from progenitors
- Modulation of pro-inflammatory cytokines
- Supportive use during/after immunosuppressive therapy
Researched dosing
This table reflects the dosing courses used in the cited Russian clinical studies for Thymalin — presented as research-methodology reference, not personal usage guidance.
| Phase | Dose | Frequency | Route |
|---|---|---|---|
| Russian label (adult immunodeficiency) | 5-20 mg | Once daily for 3-10 days (total course 30-100 mg) | IM |
| COVID-19 RCT protocol | 10 mg | Once daily for 10 days | IM |
| Geroprotective (annual course) | 5-10 mg/day | Once daily for 5-10 days, repeated annually | IM |
| Pediatric (Russian label, 7–14 yr) | 3-5 mg | Once daily for 3-10 days | IM |
Commonly cycled 2 weeks on, 12+ weeks off.
How it works
At the cell level, Thymalin research looks at how its component peptide fragments may help guide immature immune cells into mature, functioning ones, and how they interact with inflammation-related genes — the terms below describe those same biological steps.
Accelerates differentiation of CD117+ hematopoietic progenitors into mature CD28+ T-lymphocytes. Constituent EW and KE dipeptides bind specific DNA motifs (GGAG and GCGC respectively) and act as epigenetic modulators of cytokine gene expression. Downstream effects include reduced TNF-alpha, IL-6, and IL-1beta, restored CD4+/CD8+ ratios, and increased phagocytic activity.
Pharmacokinetics
This chart is a modeled estimate based on the short-lived peptide fragments Thymalin contains — no full human pharmacokinetic study of Thymalin itself has been published, so treat the curve as a research reference point.
- Peak
- 0.05 hr
- Half-life
- 0.5 hrs
- Cleared
- ~2.5 hrs
Khavinson et al. 2021 Biology Bulletin Reviews
Research applications
This section summarizes the research areas — immune-cell development, inflammation markers, and related outcomes studied mostly by one Russian research group — a summary of published research, not medical claims verified by independent replication.
Immunity
Approved Russian indication for immunodeficiency in elderly populations, linked to the 6-8 year geroprotective trial showing reduced respiratory infection incidence. Approved Russian indication for immune support during oncology treatment to mitigate treatment-induced lymphopenia. In vitro evidence in human HSCs shows 2-3-fold reduction in CD117 (progenitor marker) and 6.8-fold increase in CD28 (mature T-cell marker).
Inflammation
Downstream modulation of pro-inflammatory cytokines including TNF-alpha, IL-6, and IL-1beta. COVID-19 RCT showed IL-6 reduced 5.5-fold and CRP reduced 9.7-fold versus standard care.
Longevity
Longitudinal geroprotective study reported 2.0-2.5-fold reduction in all-cause mortality for Thymalin alone over 6 years. Annual courses in elderly subjects associated with reduced acute respiratory infections.
Recovery
Used as adjunct support in post-chemotherapy and post-radiotherapy immune recovery per Russian pharmaceutical approval.
Dosage reference
- Doses used in research
- 5–20 mg per dose (Russian label)
- Frequency in studies
- Once daily for a 3-10 day course
- Handling
- Reconstituted solution — research use only; not for administration
- Timeline reported in studies
- Lymphocyte and CD4+ shifts measurable within 7-10 days in the COVID-19 RCT. Geroprotective effects assessed over 6+ years.
- Storage
- Lyophilized: 2-8°C. Reconstituted: use immediately, do not store.
- Cycle length
- 3-10 days per course; 30-100 mg total per course
- Break between cycles
- Standard interval is every 3-6 months, or annual cycles for geroprotective protocols
Interactions
This list shows which other compounds and peptides researchers flag alongside Thymalin, and why.
Reconstitution & storage
This is the laboratory method the Russian product label specifies for turning Thymalin powder into a solution, using sterile saline rather than the bacteriostatic water common to other peptides.
- Allow vial to reach room temperature for 5-10 minutes
- Reconstitute with 1-2 mL of 0.9% sodium chloride immediately
- Add solvent slowly down the vial wall; do not shake
- Gently swirl until fully dissolved (solution should be clear)
- Draw the full reconstituted volume into a single syringe
- Do not store reconstituted product; use the same day
Lyophilized: 2-8°C, use within As per manufacturer expiry (Samson-Med)
Reconstituted: 2-6°C, use within Use immediately; do not store reconstituted solution
Open the Thymalin reconstitution calculatorQuality indicators
These are the checks — original packaging, batch documentation, solution clarity — researchers and buyers use to confirm a Thymalin sample is genuine and hasn't degraded.
White lyophilized powder - Legitimate Thymalin appears as a white to off-white lyophilized powder. Discoloration, browning, or visible moisture indicates degradation.
Sealed vial with Samson-Med label - Original Russian product carries Samson-Med branding, batch number, expiry date, and Roszdravnadzor registration LS-000267. Inspect seals and labeling for tampering.
Clear reconstituted solution - Reconstituted Thymalin should be completely clear and colorless. Cloudiness, particulates, or precipitate after gentle swirling indicate impurity or degradation.
Refrigerated cold chain - Lyophilized vials require 2-8°C storage. Verify the product has not been exposed to freezing or room temperature shipping without cold packs.
Verify product is Thymalin, not Thymulin - Vendors sometimes mislabel or confuse the two. Confirm the vial label, COA, and product page specifically say Thymalin (polypeptide complex), not Thymulin (FTS nonapeptide).
Batch variability for an extract - Thymalin is a multi-peptide extract rather than a defined single peptide. Batch-to-batch consistency from non-Samson-Med sources cannot be assumed. Prefer pharmacy-channel material with batch documentation.
Reconstitute with sterile saline, not BAC water - The Russian label specifies 0.9% sodium chloride. Use the labeled solvent and inject the full volume the same session; do not store reconstituted product.
Cloudy, yellow, or particulate solution - Discard. Indicates degradation, contamination, or incorrect reconstitution.
What to expect
This timeline summarizes what the cited clinical and observational studies report at each stage — research context for comparing studies, not a personal-results promise, and nearly all of it comes from one research group without independent replication.
No immediately perceptible effects expected
In the COVID-19 RCT, lymphocyte and CD4+ counts increased and IL-6 / CRP / D-dimer decreased over this window
Effects on infection rates and immune markers reported over weeks to months
Outcomes assessed over multiple annual cycles, not single courses
Safety notes
This section covers regulatory status and handling cautions for Thymalin — it is not FDA- or EMA-approved, and this is research-use-only scope, not medical advice.
- Russian label contraindications: known hypersensitivity to thymic proteins, pregnancy, lactation
- Not studied in solid organ or bone marrow transplant recipients on immunosuppression
- Not studied in active autoimmune disease; theoretical concern with pro-T-cell mechanism
- Use during oncology treatment should be coordinated with the treating oncologist
- Not FDA-approved or EMA-approved
- Registered pharmaceutical in Russia since 1982 (Roszdravnadzor LS-000267)
- AE reporting in published trials does not meet modern ICH/CTCAE standards
Regulatory status
- Not approved by the FDA for any indication.
- Supplied and described for laboratory research use only — not for human or veterinary use.
Community data
Community Insights
Based on data the community reported. Not clinical proof.
References
Randomized controlled trial in 42 Thymalin-treated and 50 control COVID-19 patients. Thymalin arm showed lymphocytes +55%, T-lymphocytes +63.8%, CD4+ cells +88.9%, IL-6 reduced 5.5-fold, D-dimer reduced 5.7-fold, CRP reduced 9.7-fold versus standard care.
Longitudinal study of elderly subjects receiving annual courses of Thymalin versus untreated controls. Reported 2.0-2.5-fold reduction in all-cause mortality for Thymalin alone and 4.1-fold for combined Thymalin+Epithalamin regimen over 6 years, plus 2.0-2.4-fold reduction in acute respiratory infections.
Thymalin reduced CD44 and CD117 (stem/progenitor markers) by 2-3-fold and increased CD28 (mature T-cell marker) by 6.8-fold in cultured human hematopoietic stem cells, supporting the hypothesis that Thymalin accelerates maturation of CD117+ progenitors into functional T-lymphocytes.