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.
TB-500 Dosage Chart, Schedule & Reconstitution Protocol
Quickstart Highlights
TB-500 is a synthetic version of the N-terminal 17-amino-acid actin-binding fragment of thymosin beta-4 (containing the conserved LKKTETQ motif that defines beta-thymosin family actin sequestration), the principal G-actin sequestering peptide in mammalian cytoplasm and the most abundant cytosolic protein in many cell types. It binds monomeric G-actin and modulates the dynamic equilibrium between G-actin and filamentous F-actin, promoting cell migration, angiogenesis through upregulation of VEGF, downregulation of inflammatory cytokines including TNF-alpha and IL-1 beta, and recruitment of CD34-positive endothelial progenitor cells to sites of tissue injury. Native thymosin beta-4 has been evaluated in clinical trials (RegeneRx) for diabetic neurotrophic keratopathy, epidermolysis bullosa wounds, pressure ulcers, and post-myocardial infarction repair. Researchers study TB-500 for tendon, ligament, and muscle injury recovery in animal models and in unsupervised human use. Foundational work appears in PMID 12714043 (Smart 2003) and PMID 17204577 (Goldstein 2005).
Reconstitute: Add 3 mL bacteriostatic water → 1.67 mg/mL concentration.
Easy measuring: At 1.67 mg/mL, 1 unit = 0.01 mL = 0.0167 mg (17 mcg) on a U-100 insulin syringe.
Storage: Lyophilized frozen; reconstituted refrigerated; avoid freeze–thaw cycles of reconstituted solution.
Plasma half-life: Approximately 2 to 3 days for the fragment, with tissue retention longer due to actin binding. Twice-weekly dosing is common in research protocols based on this prolonged exposure profile.
Onset: Cellular effects on actin dynamics and endothelial migration occur within hours in vitro; clinical wound-healing effects in animal models are typically assessed at 7 to 21 days of dosing.
Regulatory status: Not approved by FDA, EMA, or other major regulators. Prohibited in-competition and out-of-competition by the World Anti-Doping Agency (WADA) under S2 (peptide hormones, growth factors, and related substances).
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 3.0 mL bacteriostatic water with a sterile syringe.
Inject slowly down the vial wall; avoid foaming.
Gently swirl/roll until dissolved (do not shake).
Inject slowly; wait a few seconds before withdrawing the needle to prevent backflow.
Do not aspirate for subcutaneous injections; inject slowly and steadily[14].
Interactive TB-500 Syringe Calculator
Currently visualizing the 5 mg vial reconstituted with 3 mL bacteriostatic water. Adjust the target dose to dynamically render syringe units.
Reconstitution Calculation: 5mg dry powder in 3mL water yields 1.67 mg/mL. To evaluate a 250mcg dose, pull to 15.0 units (15 syringe ticks).
U-100 Syringe Representation
15.0 Units (15 Ticks)
Educational reference visual. Assumes standard U-100 insulin syringe where 1.0 mL volume = 100 units.
Titration & Dose Escalation Schedules
| Phase | Daily Dose (mcg) | Units (per injection) (mL) |
|---|---|---|
| Weeks 1–2 | 500 mcg | 30 units (0.30 mL) |
| Weeks 3–4 | 600 mcg | 36 units (0.36 mL) |
| Weeks 5–8 | 750 mcg | 45 units (0.45 mL) |
| Weeks 9–12 | 1000 mcg | 60 units (0.60 mL) |
Administration guidelines: Refer to guidelines | 3 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 (TB‑500, 5 mg each):
- check8 weeks ≈ 8 vials
- check12 weeks ≈ 12 vials
- check16 weeks ≈ 16 vials
Insulin Syringes (U‑100):
- checkPer week: 7 syringes (1/day)
- check8 weeks: 56 syringes
- check12 weeks: 84 syringes
- check16 weeks: 112 syringes
Bacteriostatic Water (10 mL bottles): Use ~3.0 mL per vial for reconstitution.
- check8 weeks (8 vials): 24 mL → 3 × 10 mL bottles
- check12 weeks (12 vials): 36 mL → 4 × 10 mL bottles
- check16 weeks (16 vials): 48 mL → 5 × 10 mL bottles
Alcohol Swabs: One for the vial stopper + one for the injection site each day.
- checkPer week: 14 swabs (2/day)
- check8 weeks: 112 swabs → recommend 2 × 100‑count boxes
- check12 weeks: 168 swabs → recommend 2 × 100‑count boxes
- check16 weeks: 224 swabs → recommend 3 × 100‑count boxes
Mechanism of Action (MOA)
Thymosin beta-4 is the most abundant member of the beta-thymosin family and exists in millimolar concentrations within virtually every nucleated cell, where its principal known function is sequestering monomeric G-actin and preventing premature polymerization into F-actin filaments [1][3]. The full-length 43-amino-acid Tbeta4 binds G-actin in a 1:1 stoichiometry at a defined groove on the actin surface; release of G-actin from this complex permits regulated actin filament assembly during cell migration, division, and shape change. TB-500, the synthetic peptide widely used in research, corresponds to the highly conserved actin-binding fragment of Tbeta4 (residues 17-23, sequence LKKTETQ) and reproduces many of the cellular effects of the full-length molecule [2]. Beyond actin sequestration, Tbeta4 binds intracellular ATP, modulates inflammatory cytokine release, and is taken up into the nucleus and mitochondria, where additional regulatory roles have been described. Tbeta4 promotes endothelial cell migration through upregulation of VEGF and downregulation of inflammation, drives angiogenesis in ischemic tissue, accelerates re-epithelialization in skin wound models, and reduces myocardial infarct size in animal models when administered after coronary artery ligation [3][7]. The peptide has a short plasma half-life of approximately 2 hours after subcutaneous injection, but tissue retention and incorporation into wounded tissue extend the practical biological effect [8]. Common research routes include subcutaneous injection in the abdomen or thigh, intramuscular injection at injury sites, intra-articular injection in tendinopathy or arthropathy research, and topical application in ophthalmologic and dermatologic research. Dose ranges in research protocols typically follow a loading phase of 5 to 10 mg/week (divided into one or two subcutaneous doses) for 4 to 6 weeks, then a maintenance phase of 2 mg/week for an additional 4 to 12 weeks, with rest periods between cycles. Common research applications include tendon and ligament injury healing (Achilles, rotator cuff, anterior cruciate ligament), muscle strain recovery, dermatologic wound healing studies, corneal wound healing trials (with topical formulations), and cardiac repair models (post-MI). Reported outcomes include faster return to baseline function in tendon injury cohorts, reduced inflammation markers, increased granulation tissue formation in wound healing models, and improved corneal re-epithelialization rates in dry eye and corneal abrasion studies. Critical caveats include the absence of large randomized double-blind placebo-controlled trials in humans for any orthopedic indication, the lack of validated efficacy biomarkers, and the WADA prohibition that excludes use by competitive athletes. TB-500 is detectable in urine by mass spectrometry methods used in anti-doping laboratories, and the tissue incorporation of the peptide produces a longer detection window than the plasma half-life alone would predict, which makes clean-window planning before competition difficult. Combination protocols with BPC-157 are the most common use pattern in unregulated research because the two peptides act through complementary mechanisms (VEGFR2-driven angiogenesis plus actin-mediated cell migration) and have non-overlapping dosing schedules that fit a single cycle architecture. Loading doses are concentrated in the first 4 to 6 weeks to establish biological effect, after which maintenance doses sustain that effect with reduced injection burden. Topical and intra-articular formulations of TB-500 and related thymosin beta-4 peptides are being explored in ophthalmologic and orthopedic research applications, although large-scale clinical development beyond the early phase 2 ulcer trials has stalled.
Clinical Trial Efficacy Highlights
- starA European phase 2 randomized double-blind placebo-controlled study of topical thymosin beta-4 (RGN-137) in venous stasis ulcers showed complete healing in approximately 25 percent of treated patients within 3 months, with the strongest effects in small to moderate ulcers and safety comparable to placebo [5].
- starA phase 2 study of topical thymosin beta-4 in pressure ulcers reported accelerated healing time by nearly 30 days in treated patients who reached complete closure, with no serious adverse events, supporting tolerability but with modest effect size [6].
- starGoldstein and colleagues (Ann N Y Acad Sci, multiple reviews) have established the regenerative biology of Tbeta4 across wound healing, cardiac repair, corneal regeneration, and neuroprotection in preclinical models, providing the mechanistic foundation for clinical translation [1][3].
- starBock-Marquette and colleagues demonstrated in a mouse model of myocardial infarction that systemic thymosin beta-4 administered after coronary artery ligation reduced infarct size, preserved cardiac function on echocardiography, and stimulated epicardial cell migration and progenitor recruitment [7].
- starSosne and colleagues reported in phase 2 ophthalmic trials that topical thymosin beta-4 accelerated corneal re-epithelialization in dry eye disease and neurotrophic keratitis, with favorable tolerability and improvement in patient-reported symptom scores [8].
- starIn rodent skin wound models, thymosin beta-4 accelerated re-epithelialization, increased angiogenesis as measured by CD31 staining, and reduced inflammatory infiltrate, supporting the mechanism of action across multiple tissue compartments [9].
- starIn animal models of tendon and ligament injury, thymosin beta-4 administered systemically improved biomechanical recovery, collagen organization, and tendon fibroblast migration, providing the preclinical rationale for orthopedic use although no large-scale human orthopedic RCT has been completed [10].
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.
- warningTB-500 is generally well tolerated in published human ulcer and ophthalmic trials, with adverse event rates comparable to placebo and no serious adverse events attributable to the peptide.
- warningInjection site reactions including transient erythema, mild pain, and pruritus are the most common adverse events with subcutaneous administration; reactions typically resolve within 24 hours.
- warningMild fatigue, lethargy, and transient flu-like symptoms have been described anecdotally during the first few days of loading-phase dosing, possibly reflecting initial immune modulation, but are not consistently reported in published studies.
- warningTheoretical concerns include angiogenesis-related effects on occult malignancies; Tbeta4 promotes vascularization, which could theoretically support tumor growth, although no direct evidence of tumor promotion has been demonstrated in clinical studies.
- warningTB-500 is on the WADA Prohibited List under S2 (peptide hormones, growth factors, related substances and mimetics) and is banned in competitive sport at all times, in and out of competition; athletes face sanctions if detected.
- warningLong-term safety data are essentially absent; published human exposure is limited to short-term courses of weeks to a few months, and chronic dosing safety is not characterized.
- warningUse in pregnancy, lactation, and pediatric populations has not been adequately studied and is not recommended; no teratogenicity studies meeting modern regulatory standards have been published.
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 TB-500 dosage?expand_more
Research protocols typically use 2 to 10 mg/week subcutaneously, divided into one or two doses, during a 4 to 6 week loading phase, followed by maintenance at 2 mg/week for an additional 4 to 12 weeks. Topical and intra-articular formulations use different dose ranges depending on the specific research application.
How is TB-500 used in research protocols?expand_more
Common research applications include tendon and ligament injury, muscle strain, skin wound healing, cardiac repair models, and corneal regeneration. Outcome measures include functional return-to-activity timelines, imaging-based tissue assessment, biomarkers of inflammation, and patient-reported outcomes.
Can TB-500 be combined with other peptides?expand_more
TB-500 is commonly stacked with BPC-157 in research healing protocols on the rationale that the two peptides act through complementary mechanisms (actin-mediated cell migration plus VEGF-driven angiogenesis). Combinations with GHK-Cu and KPV in topical and injectable formulations are also studied.
What are the side effects of TB-500?expand_more
Most users report mild injection site reactions and occasional transient fatigue during loading. Theoretical concerns about angiogenesis effects on occult malignancy exist but have not been confirmed in clinical studies. Long-term safety data are sparse; use in competitive sport is prohibited by WADA.
Is TB-500 FDA approved?expand_more
No. TB-500 is not approved by the FDA, EMA, or other major Western regulators for any indication. It is used only in research contexts and is banned by the World Anti-Doping Agency under category S2 of the Prohibited List.
Academic References & Study Citations
Goldstein AL, Hannappel E, Kleinman HK. Thymosin beta4: actin-sequestering protein moonlights to repair injured tissues. Trends Mol Med. 2005;11(9):421-429. View Scientific Paper →
Crockford D, Turjman N, Allan C, Angel J. Thymosin beta4: structure, function, and biological properties supporting current and future clinical applications. Ann N Y Acad Sci. 2010;1194:179-189. View Scientific Paper →
Goldstein AL, Hannappel E, Sosne G, Kleinman HK. Thymosin beta4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opin Biol Ther. 2012;12(1):37-51. View Scientific Paper →
Philp D, Goldstein AL, Kleinman HK. Thymosin beta4 promotes angiogenesis, wound healing, and hair follicle development. Mech Ageing Dev. 2004;125(2):113-115. View Scientific Paper →
Guarnera G, DeRosa A, Camerini R. The effect of thymosin treatment of venous ulcers. Ann N Y Acad Sci. 2010;1194:207-212. View Scientific Paper →
Treadwell T, Kleinman HK, Crockford D, Hardy MA, Guarnera GT, Goldstein AL. The regenerative peptide thymosin beta4 accelerates the rate of dermal healing in preclinical animal models and in patients. Ann N Y Acad Sci. 2012;1270:37-44. View Scientific Paper →
Bock-Marquette I, Saxena A, White MD, Dimaio JM, Srivastava D. Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. 2004;432(7016):466-472. View Scientific Paper →
Sosne G, Qiu P, Goldstein AL, Wheater M. Biological activities of thymosin beta4 defined by active sites in short peptide sequences. FASEB J. 2010;24(7):2144-2151. View Scientific Paper →
Malinda KM, Sidhu GS, Mani H, et al. Thymosin beta4 accelerates wound healing. J Invest Dermatol. 1999;113(3):364-368. View Scientific Paper →
Xu TJ, Wang Q, Ma XW, Zhang Z, Zhang W, Xue XC, Zhang C, Hao Q, Li WN, Zhang YQ, Li M. A novel dimeric thymosin beta4 with enhanced activities accelerates the rate of wound healing. Drug Des Devel Ther. 2013;7:1075-1088. View Scientific Paper →