TB-500 Nasal Spray 10mg

TB-500 is the research-supply name applied to a synthetic seven-residue compound whose sequence — Leu-Lys-Lys-Thr-Glu-Thr-Gln — corresponds to a region of the larger Thymosin β-4 protein. Thymosin β-4 is a 44-amino-acid intracellular protein that was first characterised in the 1980s as the principal G-actin-sequestering peptide in mammalian cells. The seven-residue fragment supplied here contains the segment most often referenced as the actin-binding motif of the parent compound.

One framing point matters before reading any of the literature on this page: most of the published biological-activity research uses the full 44-residue Thymosin β-4 protein, not the seven-residue fragment specifically. Activity inferences for the supply-form compound derive from the assumption that the binding motif retains parent function in isolation. Researchers planning new work should treat the parent literature as background context, not as direct evidence of fragment activity, and design experiments accordingly. The compound has been investigated under research-context framings rather than therapeutic-development framings.

The compound is supplied as a lyophilized white-to-off-white powder in a lyophilized in a 10 mL intranasal-spray bottle; reconstituted with the included 0.3% potassium sorbate solution. Each vial contains 10 mg of peptide. Reconstitution with bacteriostatic water is required before the peptide can be drawn into an insulin syringe. Reconstitution mechanics are covered in the Reconstitution accordion below.

The parent Thymosin β-4 has been the subject of an extensive preclinical literature spanning cardiac repair (PMID 15565145), corneal wound healing (PMID 11950239), dermal repair, angiogenesis (PMID 9194528), and musculoskeletal injury models. A 2024 review in Cells documented developmental expression patterns of Thymosin β-4 and its sibling Thymosin β-10 across human organs (PMID 38994967). A 2026 review in Peptides compiled emerging renal-research applications of the parent protein (PMID 41570941). A 2026 review in Sports Medicine covered the broader peptide-therapy landscape for musculoskeletal injuries, including discussion of regulatory status across approved and unapproved compounds in the class (PMID 41966639).

Across this body of literature the parent has appeared under several names — Thymosin β-4, Thymosin Beta 4, Tβ4, TMSB4X (the human gene symbol), and the development-era designation TB4. The supply-form fragment is typically labelled TB-500. Researchers should not assume that data on the parent translates one-to-one to the fragment without explicit pharmacokinetic and binding studies of the fragment itself.

No regulatory authority — Health Canada, the FDA, the EMA, the TGA, or any equivalent — has cleared TB-500 or the parent Thymosin β-4 for therapeutic use in humans or animals. The parent protein progressed through Phase 2 trials under RegeneRx Biopharmaceuticals for narrow wound-healing indications (notably venous stasis ulcers and epidermolysis bullosa) but has not advanced to a marketed therapeutic. Ronin Peptides ships the compound exclusively as a research-grade reagent for benchwork. Dosing protocols, treatment regimens, and administration instructions are out of scope and are not provided in any form.

The mechanistic anchor for the parent compound Thymosin β-4 is its role as the principal G-actin-sequestering peptide in mammalian cells. Research has investigated how Thymosin β-4 binds monomeric (G-form) actin and holds it in a complex that resists incorporation into filamentous (F-form) actin. By regulating the size of this G-actin pool, the parent modulates the dynamics of actin-cytoskeleton turnover, which in turn shapes cell migration, division, and adhesion remodelling. A 2001 study in the Journal of Biological Chemistry characterised the ternary complex formed between profilin, Thymosin β-4, and actin, clarifying how the parent peptide and profilin together gate the kinetics of actin polymerisation (PMID 11579089).

Cell-migration findings in the parent literature follow from this actin-pool regulation. A 1997 study in FASEB Journal reported that Thymosin β-4 stimulated directional migration of human umbilical vein endothelial cells, providing one of the foundational angiogenesis observations for the parent (PMID 9194528). Later research extended the migration findings to dermal cells, corneal epithelium, and cardiac progenitor populations.

Cardiac-research mechanism work centred on a 2004 Nature paper that reported Thymosin β-4 activates integrin-linked kinase and promoted cardiac cell migration, survival, and post-infarct repair in mouse models (PMID 15565145). The paper became a high-impact reference for the cardiac-progenitor branch of the literature and shaped subsequent therapeutic-research framing of the parent. A 2012 review in Current Pharmaceutical Design compiled the cardiac-repair findings then in development (PMID 22236126).

Angiogenesis pathway work has continued into recent years. A 2020 paper in the International Journal of Molecular Medicine described Thymosin β-4 effects on Notch and NF-κB signalling in a critical-limb-ischemia mouse model, observing parent-driven new-vessel formation and improved tissue perfusion (PMID 32945357). The Notch-NF-κB framing complemented the earlier endothelial-migration line of work and broadened the molecular framework around angiogenic activity.

Mechanism research on the seven-residue fragment specifically remains comparatively thin. The supply-form compound retains the Leu-Lys-Lys-Thr-Glu-Thr-Gln segment that overlaps the parent's actin-binding region; whether the isolated fragment recapitulates the full pharmacology of the parent across the cardiac, corneal, dermal, and musculoskeletal research models remains an active investigation question. Researchers studying fragment-specific behaviour should review the most current research literature before designing experimental protocols, with attention to whether reported observations come from parent-protein experiments or from fragment-exposure experiments.

The parent Thymosin β-4 literature spans several research streams that collectively shape how the supply-form fragment is interpreted. Cardiac repair has produced one of the more extensive bodies of work, with the 2004 Nature paper on integrin-linked kinase activation (PMID 15565145) and the 2012 Current Pharmaceutical Design protein-therapy review (PMID 22236126) anchoring the early-2010s framing. Cardiac progenitor mobilisation, post-infarct migration into the injured myocardium, and survival of resident cardiac cell populations form the principal findings of this stream.

Corneal wound healing has produced a parallel research line. A 2002 study in Experimental Eye Research reported that the parent protein promoted corneal epithelial repair and reduced inflammation in a rabbit alkali-injury model (PMID 11950239). A 2016 review in Vitamins and Hormones compiled the ocular-surface findings, framing Thymosin β-4 as a candidate research compound for neurotrophic keratopathy, dry-eye, and broader ocular-surface conditions (PMID 27450739). A 2025 paper in Investigative Ophthalmology & Visual Science examined an engineered tandem variant of the parent peptide in corneal wound-healing models, extending the line of work into engineered fragment-based research (PMID 41235866).

Dermal and wound-healing research has produced both basic-science findings and clinical-trial-stage data. The clinical line is anchored by a 2007 European prospective randomised study on the parent in venous-ulcer patients, published in Annals of the New York Academy of Sciences, reporting safety and tolerability outcomes from a Phase 2 design (PMID 17495250). A 2016 review in Vitamins and Hormones compiled the dermal-healing literature on Thymosin β-4 across the basic and translational spans (PMID 27450738). A 2024 in vitro study in Aesthetic Plastic Surgery examined adipose-stem-cell regulation in the context of fat-graft survival (PMID 38409346), broadening the soft-tissue research portfolio.

Musculoskeletal-injury research forms the application bracket most often associated with the supply-form compound in the research-peptide market. A 2026 narrative review in Sports Medicine compiled studies on approved and unapproved peptide therapies for musculoskeletal injuries, including discussion of fragment-based variants in the Thymosin β-4 lineage (PMID 41966639). Researchers reading this review should attend to the regulatory framing as much as the mechanism framing — the parent compound has not been approved by any major regulatory body for musculoskeletal indications, and the review frames the fragment in the unapproved-compound bracket.

Translation to human clinical application has been narrower than the breadth of the preclinical literature would suggest. The RegeneRx Biopharmaceuticals development programme advanced the parent through Phase 2 stages for select wound-healing indications — venous ulcers, epidermolysis bullosa, dry eye — but did not produce a marketed therapeutic. The 2024 Cells developmental-expression review (PMID 38994967) and the 2026 Peptides renal-research review (PMID 41570941) represent the current expansion-era framing of the parent's research applications, with continuing work on emerging therapeutic candidates.

One specification note worth flagging: the molecular-weight figure varies across published supply-side documentation depending on whether the compound is reported as the free acid, the acetate salt, or under a different counterion convention. The 889 g/mol value above corresponds to the acetate-salt form most commonly seen in research-supply COAs. Researchers integrating this compound into mass-spec-coupled protocols should verify the salt form and monoisotopic mass against the COA returned for the specific batch in hand.

Unopened lyophilized vials hold up well under dry ambient storage; usable activity persists for several weeks even without refrigeration. The recommended container is the unopened original vial — keep the seal intact until reconstitution. Refrigeration at 2–8 °C is appropriate once the working timeline extends past a month. A standard freezer at −20 °C handles archival storage; ultra-low storage at −80 °C is rarely needed for typical bench-research timescales.

Keep vials shielded from light, ideally in their original outer packaging. Repeated temperature cycling accelerates degradation noticeably more than steady storage at any single temperature inside the recommended bands — minimise transitions between cold and ambient.

After reconstitution, refrigerate the solution at 2–8 °C without delay. The typical working window for a reconstituted preparation is four to six weeks at fridge temperature. Past that window, peptide concentration drifts downward through chemical degradation pathways even though the bacteriostatic water's benzyl alcohol still suppresses microbial growth. The 0.9% benzyl alcohol holds back bacterial contamination — the dominant spoilage path — but does not arrest the slower hydrolysis, oxidation, and aggregation processes that accumulate in any aqueous peptide solution.

When a research timeline extends past six weeks, common practice is splitting the reconstituted solution into single-use volumes and freezing them at −20 °C immediately. Ice-crystal formation during each freeze-thaw cycle inflicts mechanical damage on peptide chains, and pre-splitting eliminates the cumulative loss that comes from thawing one vial multiple times. Thaw individual aliquots overnight in a refrigerator — never at room temperature — and use them within a few days of thaw.

The reconstituted product should be visually clear and colourless. Discard any vial showing turbidity, suspended particulate, yellowing, or visible precipitate. The diluent of choice is USP-grade bacteriostatic water containing 0.9% benzyl alcohol — see the bacteriostatic water product page for reconstitution-grade water.

TB-500 and BPC-157 are the two most-studied tissue-repair peptides in the research-peptide segment and are often examined together — see the BPC-157 + TB-500 blend for combined-compound research convenience. The mechanisms are non-overlapping: TB-500's parent regulates actin-cytoskeleton dynamics, while BPC-157 acts on vascular signalling pathways through VEGFR2. GHK-Cu and KPV cover separate repair niches and are typically investigated as standalone compounds.

This nasal spray ships unreconstituted. The peptide is supplied lyophilized in a 10 mL intranasal-spray bottle together with the 0.3% potassium sorbate solution required to reconstitute it (included) — potassium sorbate acts as a preservative suited to an intranasal solution. Add the full 10 mL of the included solution to reconstitute; the resulting concentration is the bottle’s peptide load divided by 10 mL. A typical metered intranasal actuation delivers approximately 0.1 mL, so each spray delivers roughly one-hundredth of the total peptide load.

1. Bring the spray bottle and the included 0.3% potassium sorbate solution to room temperature.
2. Sanitise the stoppers with an alcohol swab.
3. Add the full 10 mL of the included 0.3% potassium sorbate solution to the lyophilized peptide, directing the liquid against the inner wall — never onto the lyophilized cake.
4. Invert slowly or swirl gently until dissolved. Do not vortex or shake.
5. Attach the spray pump to the bottle and prime it before first use.
6. Store the reconstituted solution refrigerated at 2–8 °C and avoid repeated freeze–thaw cycles.

1. Yarmola EG et al. Formation and implications of a ternary complex of profilin, thymosin beta 4, and actin. J Biol Chem. 2001;276(49):45555-45563. PMID: 11579089 | doi:10.1074/jbc.M105723200
2. Malinda KM et al. Thymosin beta 4 stimulates directional migration of human umbilical vein endothelial cells. FASEB J. 1997;11(6):474-481. PMID: 9194528 | doi:10.1096/fasebj.11.6.9194528
3. Sosne G et al. Thymosin beta 4 promotes corneal wound healing and decreases inflammation in vivo following alkali injury. Exp Eye Res. 2002;74(2):293-299. PMID: 11950239 | doi:10.1006/exer.2001.1125
4. Bock-Marquette I et al. Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. 2004;432(7016):466-472. PMID: 15565145 | doi:10.1038/nature03000
5. Guarnera G et al. Thymosin beta-4 and venous ulcers: clinical remarks on a European prospective, randomized study on safety, tolerability. Ann N Y Acad Sci. 2007;1112:407-412. PMID: 17495250 | doi:10.1196/annals.1415.003
6. Dubé KN et al. Thymosin β4 protein therapy for cardiac repair. Curr Pharm Des. 2012;18(6):799-806. PMID: 22236126 | doi:10.2174/138161212799277699
7. Kleinman HK et al. Thymosin β4 Promotes Dermal Healing. Vitam Horm. 2016;102:251-275. PMID: 27450738 | doi:10.1016/bs.vh.2016.04.005
8. Sosne G et al. Thymosin Beta 4: A Potential Novel Therapy for Neurotrophic Keratopathy, Dry Eye, and Ocular Surface Diseases. Vitam Horm. 2016;102:277-306. PMID: 27450739 | doi:10.1016/bs.vh.2016.04.012
9. Lv S et al. Thymosin-β4 induces angiogenesis in critical limb ischemia mice via regulating Notch/NF-κB. Int J Mol Med. 2020;46(4):1347-1358. PMID: 32945357 | doi:10.3892/ijmm.2020.4701
10. Faa G et al. Thymosin β(4) and β(10) Expression in Human Organs during Development: A Review. Cells. 2024;13(13):1115. PMID: 38994967 | doi:10.3390/cells13131115
11. Li W et al. In Vitro Study of Thymosin Beta 4 Promoting Transplanted Fat Survival by Regulating Adipose-derived stem cells. Aesthetic Plast Surg. 2024. PMID: 38409346 | doi:10.1007/s00266-024-03861-1
12. Nguyen J et al. Engineered Tandem Thymosin Peptide Promotes Corneal Wound Healing. Invest Ophthalmol Vis Sci. 2025;66(14):31. PMID: 41235866 | doi:10.1167/iovs.66.14.31
13. Di H et al. Thymosin beta 4: An emerging therapeutic candidate for kidney diseases. Peptides. 2026. PMID: 41570941 | doi:10.1016/j.peptides.2026.171467
14. Mendias CL et al. Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries. Sports Med. 2026. PMID: 41966639 | doi:10.1007/s40279-026-02437-0