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.
Thymulin Dosage Chart, Schedule & Reconstitution Protocol
Quickstart Highlights
Thymulin is a zinc-dependent thymic nonapeptide hormone (pGlu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn), first isolated in 1977 as facteur thymique serique (FTS). It is active only when bound to zinc in a 1:1 ratio, forming the metallopeptide that drives T-cell differentiation and restrains pro-inflammatory cytokines (PMID 3262625, PMID 14580936). Circulating thymulin declines with age and with zinc deficiency, so it doubles as a marker of zinc status and immunosenescence. There is no established human dosage; published work is parenteral or central in animals, and even delivered by gene therapy, at microgram-level activity. Free thymulin's plasma half-life is only about 10 minutes, motivating nanoparticle and gene-therapy delivery. The subcutaneous reconstitution figures on this site are an educational measurement reference only. Thymulin is not FDA- or EMA-approved and is handled strictly as a research chemical; this is not medical advice.
Reconstitute: Add 2 mL bacteriostatic water → 2.5 mg/mL concentration.
Typical dose: 250-750 mcg/day SC (research only; not established in humans)
Easy measuring: At 2.5 mg/mL, 1 unit = 0.01 mL = 0.0250 mg (25 mcg) on a U-100 insulin syringe.
Storage: Lyophilized powder stored frozen at −20 °C and protected from light. Once reconstituted, refrigerate at 2-8 °C and use within about 2-4 weeks; avoid repeated freeze-thaw cycles of the reconstituted solution.
Half-life: Very short — free thymulin is cleared from plasma with a half-life of approximately 10 minutes, which is why depot, nanoparticle and gene-therapy delivery have been explored.
Route: Research routes are parenteral/central (IV, IP, SC, ICV) and gene therapy; modeled here as a subcutaneous reconstitution reference for measurement only. Requires equimolar zinc to be active.
Status: Not FDA- or EMA-approved for any indication; research/educational use only. No controlled human dosing trials. Educational content, not medical advice.
About Thymulin
Thymulin is a zinc-dependent thymic nonapeptide (pGlu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn) that becomes biologically active only after binding a single zinc ion, forming the metallopeptide that signals to T-cell precursors and tempers inflammatory cytokines [1][3]. Unlike approved injectable peptides, thymulin has no validated human therapeutic Thymulin dosage; in the literature it has been given parenterally (intravenous, intraperitoneal, subcutaneous) and centrally (intracerebroventricular) in animals, and even expressed via gene therapy, generally at microgram-level activity [6][7][8]. The subcutaneous reconstitution figures below are an educational measurement reference for research-grade lyophilized powder, not a clinically established regimen.\n\nThis guide models a 5 mg vial reconstituted with 2 mL of bacteriostatic water (2.5 mg/mL), so doses map cleanly onto a U-100 insulin syringe: 250 mcg = 10 units, 500 mcg = 20 units, and 750 mcg = 30 units. Because thymulin's plasma half-life is only about 10 minutes, research models favor once-daily dosing in short pulsed courses rather than continuous long-term use [9]. Critically, the peptide is inert without zinc, so any research protocol assumes adequate zinc status [4][5].\n\nFrequency: Inject once daily subcutaneously; research courses are commonly pulsed (for example, 10-20 consecutive days, then a break) rather than run continuously. Thymulin is not FDA- or EMA-approved and is presented here for educational purposes only, not as medical advice.
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 2 mL of bacteriostatic water into a sterile syringe (this yields a 2.5 mg/mL solution from a 5 mg vial, i.e., 25 mcg per insulin-syringe unit).
Inject the water slowly down the inner wall of the 5 mg thymulin vial; do not spray the stream directly onto the powder and do not shake.
Swirl or roll the vial gently until the solution is completely clear; brief, gentle handling protects the short nonapeptide.
Store refrigerated at 2-8 °C; draw the units for your research step (250 mcg ≈ 10 units, 500 mcg ≈ 20 units, 750 mcg ≈ 30 units on a U-100 syringe).
Swab the site, inject subcutaneously, and rotate sites. Educational note: thymulin requires equimolar zinc for biological activity, so research models ensure zinc sufficiency; this subcutaneous scheme is a measurement reference, not a validated human protocol.
Interactive Thymulin Syringe Calculator
Currently visualizing the 5 mg vial reconstituted with 2 mL bacteriostatic water. Adjust the target dose to dynamically render syringe units.
Reconstitution Calculation: 5mg dry powder in 2mL water yields 2.50 mg/mL. To evaluate a 250mcg dose, pull to 10.0 units (10 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) |
|---|---|---|
| Weeks 1-2 — research titration start | 250 mcg | 10 units (0.10 mL) |
| Weeks 3-4 — common research level | 500 mcg | 20 units (0.20 mL) |
| Week 5+ — upper research reference | 750 mcg | 30 units (0.30 mL) |
Administration guidelines: Refer to guidelines | 2 mL Reconstitution
Research Supplies Quantity Planner
Scientific mathematical planning of syringes, bacteriostatic water and dry vials needed for extended research blocks using the 5 mg vial.
Peptide Vials (Thymulin, 5 mg each):
- checkAt 500 mcg/day, one 5 mg vial covers about 10 days of dosing (10 doses).
- check8-week continuous course ≈ 6 vials (28 mg); 12 weeks ≈ 9 vials (42 mg); 16 weeks ≈ 12 vials (56 mg).
- checkPulsed research courses (10-20 days, repeated 2-3 times per year) use far less — often only 1-2 vials per cycle.
Insulin Syringes (U-100):
- checkOnce-daily dosing: 7 syringes per week.
- check8 weeks ≈ 56 syringes; 12 weeks ≈ 84 syringes; 16 weeks ≈ 112 syringes.
- checkAll modeled doses (10-30 units) fit comfortably within a single 0.5 mL or 1 mL U-100 syringe.
Bacteriostatic Water (30 mL bottles): Use 2 mL per 5 mg vial for reconstitution.
- check8 weeks ≈ 6 vials × 2 mL ≈ 12 mL (1 bottle).
- check12 weeks ≈ 18 mL (1 bottle); 16 weeks ≈ 24 mL (1 bottle).
- checkOne 30 mL bottle comfortably covers a full continuous course at this vial size.
Alcohol Swabs:
- check1-2 swabs per dose (vial top + injection site).
- check8 weeks ≈ 56-112 swabs; 12 weeks ≈ 84-168 swabs.
- check16 weeks ≈ 112-224 swabs; keep a zinc supply on hand too, since thymulin is inactive without adequate zinc.
Mechanism of Action (MOA)
Thymulin is a nonapeptide (pGlu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn, molecular weight ~858.9 Da) secreted by thymic epithelial cells and originally isolated as facteur thymique serique (FTS) by Bach and colleagues in 1977 [1]. Its defining feature is an absolute requirement for zinc: the apopeptide is biologically inert until it binds a single Zn2+ ion in a 1:1 (equimolar) ratio, which imposes the specific three-dimensional conformation recognized by its receptor and by conformation-specific monoclonal antibodies [2][3]. Coordination involves the N-terminal pyroglutamate region together with serine-4 and asparagine-9. This is why circulating thymulin can be physically present yet functionally absent in zinc deficiency, and why thymulin bioactivity is used experimentally as a sensitive readout of zinc status [4][5].\n\nMechanistically, zinc-bound thymulin acts on T-lymphocyte precursors to promote intra- and extra-thymic T-cell differentiation, inducing maturation markers and supporting helper, cytotoxic and natural-killer-cell function [2][4]. Beyond classical immunorestoration, a major strand of research shows that thymulin and its analogues are immunomodulatory and anti-inflammatory: they restrain over-production of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) and, in models of inflammatory and neurogenic pain, reverse hyperalgesia while damping cytokine and microglial signaling [6][7]. Thymulin also participates in bidirectional thymus-neuroendocrine crosstalk with the hypothalamic-pituitary axis and follows a circadian rhythm, and thymulin-gene-therapy approaches have been used to influence pituitary and reproductive function in aging animal models [8].\n\nPharmacokinetics are the chief practical limitation. Free thymulin is cleared from plasma extremely rapidly, with a reported half-life of approximately 10 minutes, so a single bolus produces only brief exposure [9]. This short residence time is precisely why investigators have turned to sustained-delivery strategies — polybutylcyanoacrylate (PBCA) nanoparticle encapsulation, plasmid/gene-therapy expression of a synthetic met-FTS analogue, and stabilized thymulin-related peptides such as PAT — to extend activity during chronic inflammatory conditions [7][8][9]. There is no validated human absorption or bioavailability figure for a subcutaneous thymulin product, because no such product is approved.\n\nReal-world routes in the literature are parenteral or central rather than oral: intravenous, intraperitoneal, subcutaneous and intracerebroventricular injection in animals, plus gene-therapy vectors [6][7][8][9]. The subcutaneous reconstitution scheme on this page is therefore a plausible parenteral measurement model, but the specific microgram doses shown are an educational reference, not a clinically established regimen. Because the peptide is inert without its cofactor, any research use is paired with adequate zinc; supraphysiologic zinc is not required, only sufficiency [4][5]. Thymulin is not approved by the FDA, EMA or any major regulator and is handled strictly as a research chemical.
Clinical Trial Efficacy Highlights
- starDardenne, Pléau, Blouquit and Bach (PNAS, 1985) demonstrated that thymulin's biological activity and a defining monoclonal-antibody epitope are strictly zinc-dependent: the nonapeptide binds zinc in an equimolar ratio, and this metallopeptide carries the specific three-dimensional conformation required for activity, establishing thymulin as the only thymic hormone known to require a metal cofactor [3].
- starDardenne and Pléau's review of zinc-thymulin interactions (Met Based Drugs, 1994) summarizes how serum thymulin activity tracks zinc availability, falls in zinc deficiency, and is restored by zinc supplementation in vivo and in vitro, supporting thymulin bioactivity as a sensitive functional indicator of body zinc status [4].
- starPrasad and colleagues (J Clin Invest, 1988) measured serum thymulin in three human models of mild zinc deficiency — experimentally diet-induced volunteers plus zinc-deficient sickle-cell and non-sickle-cell adults — and found thymulin activity decreased with deficiency and corrected after zinc repletion, alongside a fall in the T4+/T8+ ratio and reduced IL-2 activity, directly linking zinc status to thymulin-dependent immune readouts in humans [5].
- starSafieh-Garabedian and colleagues (Neuroscience, 2003) showed that thymulin, given before an intracerebroventricular endotoxin injection in rats, dose-dependently reversed inflammatory hyperalgesia (doses of 0.1, 0.5 and 1 µg) and differentially modulated the up-regulated pro-inflammatory cytokines across brain regions, demonstrating central anti-inflammatory and anti-nociceptive activity [6].
- starSafieh-Garabedian, Dardenne, Pléau and Saadé (Br J Pharmacol, 2002) reported that a stabilized thymulin-related peptide (PAT) produced potent, dose-dependent analgesic and anti-inflammatory effects in rat models of inflammatory hyperalgesia, reducing both mechanical and thermal hyperalgesia and supporting development of thymulin analogues with improved stability over the rapidly degraded native peptide [7].
- starReggiani and colleagues (Neuroimmunomodulation, 2011) used neonatal adenoviral thymulin (met-FTS) gene therapy in athymic nude mice, a model of accelerated neuroendocrine and reproductive aging, and improved serum luteinizing hormone and follicle-stimulating hormone, illustrating that sustained thymulin expression can influence the pituitary-gonadal axis where short-lived peptide injections cannot [8].
- starNovoselova and colleagues (PLoS One, 2018) treated mice with chronic lipopolysaccharide-induced endotoxemia using thymulin (1.5 mg/kg intraperitoneally on days 1 and 5), either free or loaded into PBCA nanoparticles; both forms reduced pro-inflammatory signaling (NF-κB, PKC-θ) and heat-shock-protein responses, with the nanoparticle formulation more effective — a direct demonstration that thymulin's ~10-minute half-life limits free-peptide efficacy and motivates depot delivery [9].
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.
- warningThere are no controlled human safety trials of injectable thymulin, so its adverse-effect profile in people is not characterized; all dosing on this page is an educational research reference, not a tested clinical regimen.
- warningAs a subcutaneous injection, the most predictable effects are local: injection-site redness, swelling, bruising or transient discomfort, minimized by sterile technique and site rotation.
- warningBecause thymulin is an immunomodulatory peptide that alters T-cell differentiation and cytokine balance, theoretical risks include over- or under-stimulation of immune responses; it would be contraindicated, on first principles, in people with autoimmune disease, active malignancy, organ transplants/immunosuppression, or pregnancy, none of which has been formally studied.
- warningThymulin is biologically inert without zinc, so co-existing zinc deficiency makes dosing ineffective; conversely, layering thymulin on top of high-dose zinc supplementation should account for zinc's own toxicity (nausea, copper depletion) at excessive intakes.
- warningIts very short ~10-minute plasma half-life means free thymulin offers only brief exposure, and unverified attempts to compensate with large or frequent doses are not supported by any pharmacokinetic safety data [9].
- warningAs a peptide, thymulin carries a general risk of immunogenicity (anti-peptide antibodies) and hypersensitivity/allergic reactions, particularly with impure research-grade material.
- warningQuality is a major hazard with research chemicals: research-grade vials are not sterile pharmaceutical products and may vary in identity, purity, endotoxin content and zinc state, none of which is guaranteed.
- warningRegulatory status: thymulin is NOT approved by the FDA, EMA or any major regulator for any indication, cannot legally be marketed as a drug or dietary supplement, and is sold only for laboratory research; this content is educational and is not medical advice.
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 Thymulin dosage?expand_more
There is no established human Thymulin dosage, because no thymulin product is approved and there are no controlled human dosing trials. In the published literature it has been given parenterally and centrally in animals at microgram-level activity (for example, 0.1-1 µg intracerebroventricular in rat pain studies, and 1.5 mg/kg intraperitoneally in mice). The educational subcutaneous reference on this site models a research range of roughly 250-750 mcg once daily from a 5 mg vial reconstituted with 2 mL of bacteriostatic water (2.5 mg/mL), where 250 mcg = 10 units, 500 mcg = 20 units, and 750 mcg = 30 units on a U-100 syringe. These figures are a measurement reference only, not medical advice.
Is Thymulin FDA approved?expand_more
No. Thymulin is not approved by the FDA, the EMA or any major regulator for any indication. It is a research compound studied largely in cell and animal models; it cannot legally be sold as a drug or marketed as a dietary supplement, and research-grade vials are intended for laboratory use only. Everything on this page is educational and is not a recommendation to use thymulin.
What is the half-life of Thymulin?expand_more
Free thymulin has a very short plasma half-life of approximately 10 minutes, so a single injection produces only brief exposure. This rapid clearance is the main pharmacokinetic limitation of the peptide and is why researchers have explored sustained-delivery approaches such as PBCA nanoparticle encapsulation, gene-therapy expression of a met-FTS analogue, and stabilized thymulin-related peptides (e.g., PAT) to prolong activity during chronic inflammatory conditions.
How is Thymulin reconstituted and administered in this educational model?expand_more
In the literature thymulin is given by injection (intravenous, intraperitoneal, subcutaneous) or centrally, not orally. For the subcutaneous measurement model here, a 5 mg vial is mixed with 2 mL of bacteriostatic water to give 2.5 mg/mL (25 mcg per insulin-syringe unit). Draw the water slowly down the vial wall, swirl gently until clear, do not shake, and refrigerate at 2-8 °C. At that concentration, 250 mcg measures 10 units, 500 mcg measures 20 units, and 750 mcg measures 30 units on a U-100 syringe.
Does Thymulin need zinc, and can it be stacked with zinc or other peptides?expand_more
Yes — zinc is essential. Thymulin is biologically inert until it binds a zinc ion in a 1:1 ratio, so in zinc deficiency the peptide is present but inactive, and research models always assume adequate zinc status. That makes zinc sufficiency (not megadosing) a practical prerequisite rather than an optional add-on. Beyond zinc, thymulin is sometimes discussed alongside other thymic peptides in research contexts, but there is no validated stacking protocol and no human safety data for any combination; treat any such use as experimental.
Related Guides & Tools
Step-by-step references for reconstituting, measuring, and storing Thymulin, plus the universal dosing calculator.
Academic References & Study Citations
Thymulin. Wikipedia (encyclopedic overview: sequence pGlu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn, molecular weight ~858.9 g/mol, discovery by Bach 1977 as facteur thymique serique, zinc dependence, T-cell and neuroendocrine roles). View Scientific Paper →
Dardenne M, Bach JF. Thymulin, a zinc-dependent hormone. Med Oncol Tumor Pharmacother. 1989;6(1):25-29. View Scientific Paper →
Dardenne M, Pléau JM, Blouquit JY, Bach JF. A zinc-dependent epitope on the molecule of thymulin, a thymic hormone. Proc Natl Acad Sci U S A. 1985;82(20):7035-7038. View Scientific Paper →
Dardenne M, Pléau JM. Interactions between zinc and thymulin. Met Based Drugs. 1994;1(2-3):233-239. View Scientific Paper →
Prasad AS, Meftah S, Abdallah J, et al. Serum thymulin in human zinc deficiency. J Clin Invest. 1988;82(4):1202-1210. View Scientific Paper →
Safieh-Garabedian B, Ochoa-Chaar CI, Poole S, et al. Thymulin reverses inflammatory hyperalgesia and modulates the increased concentration of proinflammatory cytokines induced by i.c.v. endotoxin injection. Neuroscience. 2003;121(4):865-873. View Scientific Paper →
Safieh-Garabedian B, Dardenne M, Pléau JM, Saadé NE. Potent analgesic and anti-inflammatory actions of a novel thymulin-related peptide in the rat. Br J Pharmacol. 2002;136(6):947-955. View Scientific Paper →
Reggiani PC, Poch B, Cónsole GM, et al. Thymulin-based gene therapy and pituitary function in animal models of aging. Neuroimmunomodulation. 2011;18(5):350-356. View Scientific Paper →
Novoselova EG, Lunin SM, Glushkova OV, et al. Thymulin, free or bound to PBCA nanoparticles, protects mice against chronic septic inflammation. PLoS One. 2018;13(5):e0197601 (states free thymulin half-life is approximately 10 min). View Scientific Paper →