TB-500
Thymosin / Systemic Tissue RepairAlso known as: Thymosin Beta-4 (synthetic fragment) · Tβ4
A synthetic analog of Thymosin Beta-4 with systemic tissue remodeling, anti-fibrotic, & angiogenic effects. The go-to peptide for systemic recovery & cardiac tissue repair.
Typical Dose
2–2.5 mg 2x/week (loading); 1–2 mg/week (maintenance)
Route
Subcutaneous injection (abdomen preferred)
Cycle
4–8 weeks loading, then maintenance as needed
Half-life
~3–4 days (estimated; significantly longer than BPC-157)
Storage
Lyophilized: room temp or freezer. Reconstituted: 2–8°C, use within 30 days.
Overview
TB-500 is a synthetic peptide derived from the conserved actin-binding domain of Thymosin Beta-4, a 43-amino-acid protein naturally produced by platelets & found in high concentrations at sites of injury. The active fragment (amino acids 17–23, LKKTETQ) retains the full biological activity of the parent protein for most tissue repair applications.
Its mechanism centers on upregulation of actin polymerization in endothelial & smooth muscle cells, which drives cell migration, blood vessel formation, & tissue reorganization. Unlike BPC-157, which tends to exert localized effects, TB-500 distributes systemically after subcutaneous or intramuscular injection, making it particularly effective for diffuse injury patterns or post-surgical recovery.
Clinical use of Thymosin Beta-4 itself has been studied in human trials for wound healing & cardiac repair. TB-500 is the research peptide version used outside clinical trials. Notably, it appears on WADA's prohibited list due to its muscle & connective tissue repair properties.
Quick Start Guide
Reconstitute with bacteriostatic water: 1 mL per 5 mg vial gives 5000 mcg/mL.
Loading phase: inject 2–2.5 mg (0.4–0.5 mL) twice per week for 4–6 weeks.
Maintenance phase: drop to 1–2 mg once per week.
Inject subcutaneously into the abdomen. Site rotation is important given the volume.
Research Indications
Systemic soft tissue repair
Most EffectiveTB-500's systemic distribution pattern makes it uniquely suited to repair multiple injury sites simultaneously. Rodent studies show accelerated healing of muscle, tendon, ligament, & skin with consistent angiogenesis at repair sites.
Cardiac tissue repair
Most EffectiveHuman trials of Thymosin Beta-4 have been conducted for cardiac repair post-MI. TB-500 promotes cardiomyocyte migration & survival. This is one of the strongest areas of clinical translation for the thymosin class.
Anti-fibrotic effects
EffectiveTB-500 consistently reduces collagen deposition & scar tissue formation in injury models. This makes it distinct from BPC-157 (which primarily promotes new tissue growth) & especially useful for chronic injuries where fibrosis has become a limiting factor.
Tendon & ligament repair
EffectiveStudied in equine models (FDA IND obtained). Shows improved tendon fiber alignment & reduced re-injury rates. The equine data is notably robust given the commercial incentive in veterinary use.
Hair follicle activation
ModerateThymosin Beta-4 upregulates progenitor cell activity in hair follicles. Some users report hair regrowth or density improvements, though this has not been a primary research target.
Ocular surface repair
Research OnlyTopical Thymosin Beta-4 has been in clinical development for dry eye syndrome & corneal injury. This is unlikely to translate to injectable TB-500 use but reflects the breadth of the molecule's applications.
Research Protocols
Acute injury recovery (loading phase)
4–6 weeksDose
2–2.5 mg
Frequency
Twice weekly
Route
SubQ abdomen
Front-load the dose during active tissue repair. Injection at least 48 hours apart.
Post-surgical systemic recovery
6–8 weeksDose
2 mg
Frequency
Twice weekly
Route
SubQ abdomen
Often stacked with BPC-157 (250–500 mcg/day SubQ near site) for complementary local + systemic effect.
Chronic injury with fibrosis
8–12 weeksDose
2 mg
Frequency
Twice weekly
Route
SubQ abdomen
Anti-fibrotic effects are cumulative. Longer cycles are typically run for chronic injuries than for acute ones.
Maintenance & prevention
Ongoing (cycled 8 on / 4 off)Dose
1–2 mg
Frequency
Once weekly
Route
SubQ abdomen
Wolverine Stack (with BPC-157)
4–8 weeksDose
2 mg TB-500 + 250 mcg BPC-157
Frequency
TB-500 2x/week; BPC-157 daily or 2x/day
Route
Both SubQ; BPC-157 near injury site
The most widely used combination for musculoskeletal injury. BPC-157 handles the local repair cascade; TB-500 handles systemic remodeling & anti-fibrosis.
Peptide Interactions
The Wolverine Stack. BPC-157 provides local injury-site signaling (GH receptor upregulation, localized angiogenesis); TB-500 provides systemic tissue remodeling & anti-fibrotic activity. The two mechanisms are complementary & non-overlapping. Standard doses of each are used together without modification.
Adding a GH secretagogue increases circulating IGF-1, which potentiates downstream repair signaling initiated by TB-500. Common in post-surgical recovery stacks.
GHK-Cu promotes collagen synthesis & has independent angiogenic activity. Combined with TB-500's anti-fibrotic & cell migration effects, this is a theoretically strong wound-healing stack.
Compatible; no known interaction. Occasionally stacked for a GH + repair peptide protocol.
Side Effects & Safety
Common
- Injection site redness or mild swelling (typically resolves within 24 hours)
- Fatigue or lethargy on injection days (especially early in a loading phase)
- Flu-like symptoms during the first 1–2 weeks (systemic immune activation; typically self-limiting)
Uncommon
- Headache
- Transient dizziness
- Mild nausea
- Hair growth in unexpected areas (mechanism: follicle progenitor activation)
When to Stop
- Fever above 38.5°C persisting beyond 48 hours
- Signs of allergic reaction: hives, difficulty breathing, angioedema
- Persistent injection site abscess or cellulitis
- Known or suspected malignancy (TB-500 promotes cell migration & proliferation)
- Cardiac symptoms: new chest pain, palpitations, or dyspnea
How to Reconstitute
Clean the vial stopper with an alcohol swab & allow to dry for 30 seconds.
Draw 1 mL of bacteriostatic water into a 3 mL syringe.
Insert the needle at a 45° angle & inject the BAC water slowly down the inner wall of the vial. Do not spray onto the powder.
Gently swirl (do not shake) for 30–60 seconds until fully dissolved.
The solution should be clear & colorless. Label with date.
Refrigerate at 2–8°C. Use within 30 days.
For a 2 mg dose with this 1 mL / 5 mg reconstitution (5000 mcg/mL): draw 0.4 mL. For 2.5 mg: draw 0.5 mL.
Dosing math: Standard dilution is 1 mL BAC water per 5 mg vial, yielding 5000 mcg/mL. Adjust water volume if a different concentration is preferred. For a 2 mg dose: 0.4 mL.
Quality Indicators
Good — use as normal
- Crystal clear, colorless solution after reconstitution
- Lyophilized powder is white, fluffy, & adheres to the vial base
- Dissolves fully within 60 seconds with gentle swirling
Acceptable
- Very faint yellow tint (mild oxidation at trace level; acceptable from reputable manufacturers)
- Minor clumping that fully dissolves with continued swirling
Discard immediately
- Cloudy or milky solution that does not clear
- Visible undissolved particulate after thorough swirling
- Brown, orange, or strongly yellow coloration after reconstitution
- Gel-like or fused lyophilized cake (indicates moisture contamination)
- Reconstituted solution stored at room temperature more than 48 hours
What to Expect
Week 1–2
Systemic distribution begins immediately. Some users experience flu-like symptoms in the first week as the immune system responds to the peptide. Fatigue on injection days is common during loading. Injury site pain may begin to reduce by the end of week 2.
Week 3–4
The most frequently reported window for first meaningful functional improvement: reduced stiffness, improved range of motion, & subjective reduction in scar tissue feel at chronic injury sites. Anti-fibrotic effects are accumulating.
Week 5–8
Continued tissue remodeling. New capillary networks from weeks 1–4 are now supporting improved perfusion at repair sites. Users with chronic injuries often notice the most dramatic change in this window. Transition to maintenance dosing typically happens at week 6–8.
Week 9–12 (maintenance)
On maintenance dosing (1–2 mg/week), effects plateau & consolidate. Some users cycle off entirely after week 8 & observe that structural improvements are durable. Others maintain low-dose ongoing.
Post-cycle
Effects appear to be durable — the anti-fibrotic remodeling & new vasculature that formed do not reverse. A 4-week washout before re-starting a loading phase is standard practice.
Community Insights
Self-reported. Reflects user experience, not clinical outcomes.
Research References
Kidney International · 2010
Demonstrates Thymosin Beta-4's anti-fibrotic mechanism in kidney tissue, showing reduction of TGF-beta-mediated fibrosis. Directly relevant to TB-500's anti-fibrotic reputation across tissue types.
doi:10.1038/ki.2010.166 →Nature · 2004
Landmark paper establishing TB4's role in cardiac progenitor cell activation & post-MI repair. This study forms the foundation for ongoing human cardiac trials.
doi:10.1038/nature02762 →Neurobiology of Disease · 2011
Shows nerve regeneration promotion by Thymosin Beta-4, including axon sprouting & remyelination. Relevant for TB-500 users with injury-related neuropathy.
doi:10.1016/j.nbd.2011.09.009 →Annals of the New York Academy of Sciences · 2012
Human clinical trial demonstrating statistical improvement in chronic wound healing with systemic Thymosin Beta-4 administration versus placebo.
doi:10.1111/j.1749-6632.2012.06717.x →Verify what you have
Information on this page applies to pharmaceutical-grade peptides. Purity & identity of research-grade products vary. Certipep provides independent ESI-TOF-MS & HPLC analysis with a signed analytical report.
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