Bioregulators · Dosing reference

Thymalin dosage

What the human evidence does and does not show, how long studies ran, and the arithmetic for working with vials.

Not approved — research use onlyBLimited human dataNone established

Full research page Cycle-length evidence Compare Prefer Amiravo on Google

Regulatory status: Not approved — research use only
Human amounts: None established in humans
Route studied: Intramuscular
Frequency: Not established
Half-life: Not established
Evidence grade: Grade B · Limited human data
Vial sizes on the market: 20 mg
Other forms seen: —

What Thymalin is

A short thymic peptide of the bioregulator class, studied in laboratory research on immune function and cellular aging.

Thymalin is described as acting on the immune system rather than on a single receptor, and its investigators have pursued two linked explanations: an effect on the differentiation of hematopoietic progenitors toward mature T lymphocytes, and a cytokine-suppressing effect attributed to two dipeptides within the complex ^1,5. Hematopoietic stem cell differentiation In cultured human hematopoietic stem cells, thymalin… How it works →

Key evidence

Khavinson et al., Stem Cell Reviews and Reports · 2021 · Humans (patients with COVID-19)
Addition of thymalin to standard therapy was reported to accelerate the decline in IL-6, C-reactive protein and D-dimer and in T-cell-system measures relative to standard treatment alone. ³
Kuznik et al., Advances in Gerontology (in Russian) · 2022 · Humans (middle-aged and elderly patients with severe COVID-19)
Hospital mortality was reported as 40.9%, 28.4% and 20.6% across the three groups in the English abstract, with reported increases in lymphocytes, monocytes, leukocytes and platelets and reductions in fibrinogen, lactate dehydrogenase and D-dimer in the thymalin group. The paper's Russian-language abstract gives 40.9%, 28.8% and 16.2% for the same three groups. ⁴
Khavinson et al., Bulletin of Experimental Biology and Medicine · 2020 · Cultured human hematopoietic stem cells (in vitro)
Thymalin was reported to reduce CD44 and CD117 expression by two to three times and to increase CD28 expression 6.8-fold, interpreted by the authors as indirect evidence of stimulated differentiation toward mature T lymphocytes. ¹

All studies on the research page

What the human evidence shows

No approved or established human dose

We searched PubMed and ClinicalTrials.gov and found no human studies that administered Thymalin. The research described on its page is from cells or animals, and animal amounts do not translate to people.

How long did human studies run?

The COVID-19 trial and the HIV case series both administered thymalin for 5 days ^3,13.
In the 1989 lung-disease study, a treatment course was 4-6 injections ^14.

Cycle-length evidence for Thymalin

Who was excluded from the studies

The COVID-19 trial enrolled only hospitalized patients with moderate or severe disease, lymphopenia and CT-confirmed bilateral pneumonia; it did not report results for children or for pregnant or breastfeeding people ^3.

Thymalin draw calculator

Pick the vial strength and the water added, enter an amount, and see the concentration, the units to draw and how many draws the vial holds. Arithmetic only.

1 · Vial strength

sizes on the market

2 · Water added

3 · Amount per draw

4 · Syringe

Your mix

20 mg + 2 mL water = 10 mg/mL

10 units holds 1 mg

Draw toEnter an amount in step 3

U-100 syringe · 100 units = 1 mL

Computed from your inputs. Not a dose or a recommendation.

Compare water volumes for this vialShow

More water = lower concentration = a larger, easier-to-measure draw. Tap a row to use it.

Water	mg/mL	Draw
0.5 mL	40	—
1 mL	20	—
1.5 mL	13.33	—
2 mL	10	—
2.5 mL	8	—
3 mL	6.667	—
5 mL	4	—

Supplies and handling

Lyophilized vial
Sealed vial with the freeze-dried cake. Check the label, lot and the certificate of analysis before opening.
Sterile diluent
The diluent named on the product documentation. Bacteriostatic water contains benzyl alcohol; sterile water does not.
Graduated syringes
Sized to the volume being measured. U-100 insulin syringes are graduated in units where 100 units = 1 mL.
Alcohol prep pads
For wiping vial stoppers before each puncture.
Nitrile gloves
Clean gloves for aseptic handling.
Sharps container
Puncture-resistant container for used needles.

Step-by-step reconstitution guide Storage and transport accessories

Storage

General research-context handling only: a lyophilised protein or polypeptide fraction of animal origin is normally kept cold, dry and protected from light, and is less stable once in solution. Amiravo gives no preparation or handling instructions; defer to the supplier's documentation and to local institutional requirements, including any requirements specific to animal-derived research materials.

Lyophilized (unmixed) vials: typically stored cold and dry, away from light, as the documentation directs. Many are stable longer frozen.
Reconstituted vials: typically refrigerated (about 2–8 °C), protected from light and not frozen.
Bacteriostatic water contains benzyl alcohol, which inhibits bacterial growth in multi-use vials; sterile water has no preservative.

Handling mistakes and troubleshooting

Added the wrong volume of diluent: The concentration changes, not the amount of compound in the vial. Recalculate with the volume actually added and relabel the vial.
Shook the vial and it foamed: Let it settle in the refrigerator. Foam is a sign of agitation; some peptides aggregate when shaken. Note it on the label.
The solution is cloudy or has particles: Do not use it. Cloudiness can indicate incomplete dissolution, contamination or degradation. Record the lot and contact the supplier with the certificate of analysis.
The powder cake looks melted or shrunken before reconstitution: This can indicate the vial was exposed to heat or moisture. Record the lot and condition on arrival.
Liquid sprayed back when the needle was removed: Pressure built up in the vial. Withdraw a small volume of air while adding diluent to keep pressure neutral.

Regulatory status

Status: Not approved by the FDA for any use; no approved application and no structured product label were identified ^7,8. Reports describe it as a registered peptide drug in Russia, but that status was not verified against a primary regulatory source for this entry ^3,4.
United States (FDA): No approved application for this substance was identified in Drugs@FDA, and no structured product label for it was identified in DailyMed ^7,8. It does not appear in any of the three categories of FDA's 503A bulk drug substances list as updated May 14, 2026 (Category 1, substances under evaluation; Category 2, substances raising significant safety risks; Category 3, substances nominated without adequate support) ^11.
Sport (WADA): Thymalin is not named in the WADA 2026 Prohibited List ^12. Absence of a name is not a clearance, and it carries less weight than usual here: thymalin is a thymus polypeptide complex whose investigators identify Lys-Glu and Glu-Trp as active components ^5, and the List's classes are written as open categories using wording such as "including, but not limited to", while section S0 is described so as to cover pharmacological substances not addressed elsewhere that have no current approval from a governmental health authority for human therapeutic use ^12. A mixture can also raise questions under more than one class at once. Whether thymalin or any of its components falls within a prohibited class is a determination for anti-doping authorities.

Status varies by country and changes over time. How we describe regulatory status.

Thymalin compared with related compounds

Compound	Status	Evidence	Human amounts	Half-life
Thymalin	Not approved — research use only	B	None established	—
Vesugen	Not approved — research use only	C	None established	—
Vilon	Not approved — research use only	C	None established	—
Thymagen	Not approved — research use only	—	None established	—
Cortagen	Not approved — research use only	C	None established	—
Pinealon	Not approved — research use only	C	None established	—

Frequently asked questions

What doses of Thymalin have been studied in humans?

None that establish an amount. Thymalin is not approved anywhere and we found no human studies that administered it. Amiravo does not publish community or vendor figures.

Is there an established Thymalin cycle length?

No cycle length or break has been established. Human studies administered Thymalin for the periods listed on this page; those are study durations, not a recommended course.

How much bacteriostatic water should be added to a Thymalin vial?

There is no compound-specific volume. The diluent volume only sets the concentration: concentration = mass in the vial ÷ volume added (for example, 10 mg in 2 mL gives 5 mg/mL). The calculator on this page shows the arithmetic for any combination.

How many units is a given amount on an insulin syringe?

On a U-100 syringe, 100 units = 1 mL. Units for an amount = amount ÷ (concentration per unit). The calculator converts any amount you enter at the concentration you choose; a unit is a volume mark, not an amount of compound.

Is Thymalin FDA-approved?

Not approved — research use only. Not approved by the FDA for any use; no approved application and no structured product label were identified ^7,8. Reports describe it as a registered peptide drug in Russia, but that status was not verified against a primary regulatory source for this entry ^3,4.

References

Thymalin: Activation of Differentiation of Human Hematopoietic Stem Cells Bull Exp Biol Med. 2020
Expression features of T-lymphocytes, B-lymphocytes and macrophages in the post-traumatic regenerate of the mandible rats under conditions of filling a bone defect with hydroxyapatite-containing osteotropic material and thymalin injecting the surrounding soft tissues Pol Merkur Lekarski. 2024
Results and Prospects of Using Activator of Hematopoietic Stem Cell Differentiation in Complex Therapy for Patients with COVID-19 Stem Cell Rev Rep. 2021
[Morphological compound and indicators of the blood clotting system in severe COVID-19 patients of middle aged and elderly during treatment of Tocilizumab and Thymalin] Adv Gerontol. 2022
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
[Treatment of secretory otitis media in children, depending on the stage of the process and on the background of the pathological conditions] Georgian Med News. 2019
Drugs@FDA: FDA-Approved Drugs (search of approved applications) FDA Drugs@FDA / openFDA drug/drugsfda. 2026
DailyMed label search (structured product labels) NLM DailyMed. 2026
[Age-related characteristics of the thymus and adrenal cortex function in CBA mice immunized by T-dependent antigen] Fiziol Zh. 2005
Peptides Regulating Proliferative Activity and Inflammatory Pathways in the Monocyte/Macrophage THP-1 Cell Line Int J Mol Sci. 2022
Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the FD&C Act, updated May 14, 2026 FDA. 2026
World Anti-Doping Code International Standard: Prohibited List 2026 WADA. 2026
[HIV infection in servicemen (the work experience of a specialized hospital department)] Voen Med Zh. 1995
[Effect of thymalin on immunologic reactivity of patients with non-specific lung diseases] Ter Arkh. 1989
Peptides of pineal gland and thymus prolong human life Neuro Endocrinol Lett. 2003

Last reviewed October 23, 2026 by the Amiravo editorial team. Editorial policy · Report an error