TB-500 is a synthetic 7-amino-acid fragment of thymosin beta-4, a larger peptide found throughout the body. Its sequence is Ac-LKKTETQ, which matches amino acids 17-23 of thymosin beta-4 (Tbeta-4). The fragment keeps the actin-binding region of the parent molecule but is not the same molecule as full-length Tbeta-4.

Is TB-500 the same as thymosin beta-4?

No. TB-500 is a 7-amino-acid synthetic fragment of the 43-amino-acid full-length thymosin beta-4. Most published human clinical evidence is on full-length Tbeta-4, not the TB-500 fragment. Many research-use discussions treat them as interchangeable, but the evidence does not prove that.

What is TB-500 commonly researched for?

TB-500 is most often referenced in research-use contexts focused on actin-mediated cell migration and tissue repair signaling. Preclinical animal work on the parent peptide thymosin beta-4 covers dermal wound healing, corneal injury, cardiac ischemia, and tendon/ligament repair models. Direct human clinical trials of the TB-500 fragment specifically are absent.

What is a typical TB-500 dosing pattern in research planning?

Community-referenced research planning frequently uses about 2 to 2.5 mg subcutaneous twice weekly during a 4-6 week loading phase, then about 2 to 2.5 mg once weekly for ongoing maintenance. These numbers are not validated by a human RCT of the TB-500 fragment, and they are not a personal dosing recommendation.

How is TB-500 reconstituted?

Most planners reconstitute a 10 mg vial with 2.0 mL of bacteriostatic water, which gives 5 mg/mL. On a U-100 insulin syringe, 1 unit equals 0.01 mL or about 50 mcg, and 50 units (0.5 mL) equals 2.5 mg. Add the BAC water slowly down the wall of the vial, swirl rather than shake, and refrigerate. Use the PepPal reconstitution calculator for other vial sizes.

How long is a typical TB-500 cycle?

Common research-use cycles run 4-12 weeks. The most-referenced structure is a 4-6 week loading phase at higher frequency followed by a maintenance phase at once-weekly dosing. There is no human RCT of TB-500 establishing an optimal cycle length.

Can BPC-157 and TB-500 be used together?

The BPC-157 + TB-500 combination - sometimes called the Wolverine stack - is the most common pairing in the research-use community because the proposed mechanisms are described as complementary. The combined research-use plan is detailed on the Wolverine stack page . Combined safety in humans is not established.

Is TB-500 FDA-approved?

No. TB-500 is not approved by the FDA for any human use. It was placed on Category 2 of the FDA's interim 503A bulks list in September 2023, removed from Category 2 on April 15, 2026 because nominators withdrew their nominations, and is scheduled for Pharmacy Compounding Advisory Committee review on July 23, 2026 for potential inclusion on the 503A Bulks List for wound healing. Reclassification away from Category 2 is not the same as FDA approval.

Is TB-500 banned in sport?

Yes. The World Anti-Doping Agency lists TB-500 and all thymosin beta-4 derivatives under Section S0 (Non-Approved Substances), at all times. Reported detection windows in urine and blood are around 30-45 days. NCAA, military, and most professional sport testing programs apply WADA-aligned rules. TB-500 is also prohibited in horse racing.

What are the main TB-500 observed effects?

Direct human safety data on the TB-500 fragment is essentially absent. The closest reference is a Phase 1 study of full-length thymosin beta-4 at IV doses up to 1260 mg per day for 14 days in healthy volunteers, which reported no dose-limiting toxicities. Community-reported effects with subcutaneous TB-500 are mostly mild injection-site discomfort, short-lived fatigue, or head-pressure feelings. Theoretical concerns include effects on cancer angiogenesis and long-term immune modulation, neither of which has been characterized in humans.

Who should avoid TB-500 research?

Athletes subject to drug testing should avoid TB-500 because of the WADA prohibition. People with active or prior cancer, anyone pregnant or lactating, and anyone with allergies to peptide preparations or BAC-water preservatives should avoid it. People seeking treatment for a specific medical condition should work with a clinician through approved care pathways rather than a research peptide.

Is this medical advice?

No. This page is an educational research reference. It is not medical advice, diagnosis, or treatment guidance. TB-500 is a research peptide, not an approved medication.

TB-500 Research Protocol Reference

Phase	5 mg 1 mL water	10 mg 2 mL water
Loading — twice weekly (weeks 1–2)	—	—
Maintenance — once weekly	—	—
Acute-injury window — every 2–3 days (2 weeks)	—	—
Acute-injury window — taper, once weekly	—	—

Overview

TB‑500 is a synthetic peptide fragment corresponding to the active region of thymosin beta‑4 (Tβ4), a naturally occurring 43‑amino‑acid protein involved in tissue repair and regeneration[1][2]. This educational protocol presents a once‑daily subcutaneous approach using a practical dilution for accurate insulin‑syringe measurements in research settings. Reconstitute: Add 3.0 mL bacteriostatic water → ~1.67 mg/mL concentration. Typical daily range: 500–1000 mcg once daily (gradual titration recom

Category: Healing
Routes: subcutaneous, intramuscular

Mechanism

TB-500

Mechanism of action

TB-500 research centers on actin , a structural protein cells use to move and change shape. The parent peptide, thymosin beta-4, helps regulate the pool of actin building blocks inside cells. That matters because wound repair depends on cells moving into the right area and rebuilding tissue in an organized way. The important point: TB-500 keeps the actin-binding region of thymosin beta-4, but it does not include the rest of the parent peptide. That is why this page separates TB-500 fragment data from full-length thymosin beta-4 data. Tbeta-4 binds G-actin monomers and is one of the major regulators of the monomeric actin pool. The TB-500 fragment retains this binding motif. Preclinical work shows Tbeta-4 promotes migration of keratinocytes, endothelial cells, fibroblasts, myoblasts, and corneal epithelial cells in injury models. In animal models, Tbeta-4 promotes new blood vessel formation in dermal wounds and ischemic cardiac tissue. Tbeta-4 reduces inflammatory mediators in corneal injury models and reduces matrix metalloproteinase levels after alkali burn in animal eyes. Most of these mechanism findings are reported for full-length thymosin beta-4. Some are confirmed in fragment-only experiments; others are extrapolated.

Key research findings

01
Identity (note ambiguity): 'TB-500' is a research-chemical designation commonly associated with thymosin beta-4 (Tu03b24) or an active fragment of it; exact identity and purity are supplier-dependent.
02
In vitro / animal model: thymosin beta-4 is a naturally occurring actin-sequestering peptide involved in cell migration, with a research base spanning angiogenesis and tissue-repair processes.
03
Animal model: studies report effects on dermal wound closure, corneal/ocular surface repair, and cardiac tissue repair after injury.
04
In vitro: a short actin-binding motif (LKKTETQ) is frequently cited as central to cell-migration-related activity.
05
Human study (early phase): thymosin beta-4 itself (not the 'TB-500' research product) has been evaluated in early human trials, e.g., dermal and ocular surface repair (RegeneRx clinical program).

Primary source: Full-length Tbeta-4, Phase 1 IV safety: Ruff et al. (2010), 40 healthy volunteers, single IV doses 42-1260 mg then daily x 14 days, no dose-limiting toxicities. Establishes that IV Tbeta-4 was tolerated short-term, not that the fragment is safe long-term subcutaneously. Full-length Tbeta-4, Phase 2 dermal wound (venous ulcers): Guarnera et al. (2010), 73 patients across 8 European sites, double-blind placebo-controlled topical 0.0001-0.03% Tbeta-4 over 12 weeks. Safety profile acceptable. About 25% complete healing in 3 months at the 0.03% dose, with stronger response in smaller wounds. Full-length Tbeta-4, Phase 2 pressure ulcer: RegeneRx-sponsored Phase 2 trial (NCT00382174) of topical 0.01-0.1% Tbeta-4. Acceleration of healing reported in patients who responded. Full-length Tbeta-4, Phase 3 ophthalmic (RGN-259): SEER-1 Phase 3 trial of 0.1% topical Tbeta-4 ophthalmic solution in neurotrophic keratopathy stages 2-3. Reported faster complete healing at 4 weeks vs. placebo, no safety issues. TB-500 fragment, preclinical only: The TB-500 fragment retains actin-binding behavior in cell-biology and in-vivo animal experiments. Specific human evidence for the fragment is absent. Cardiac preclinical: Bock-Marquette et al. (2004) showed Tbeta-4 reduces infarct volume and preserves cardiac function in mouse coronary ligation models. Subsequent work in mice and a porcine MI model has reported similar effects. No human cardiac endpoint trial has been completed for systemic Tbeta-4. Tendon and ligament preclinical: Kim & Bhatt (2013) reported improved collagen organization and fibril diameter at 4 weeks after fibrin-sealant Tbeta-4 delivery in a rat MCL transection model. No human trial. Evidence boundary: The widespread research-use claim that injectable TB-500 fragment 'heals tendons and ligaments in humans' is not supported by a published human RCT. It rests on extrapolation from preclinical full-length Tbeta-4 work.

Pharmacokinetic profile

PMID:29550018

Single-dose plasma curve over 24h. Shaded band = commonly-cited therapeutic window. Illustrative only.

Researched Effects

Researched benefits

Areas of active research and investigation. Results may vary and are based on preclinical or early clinical data.

✨

Supports accelerated wound healing and tissue repair through enhanced angiogenesis and cell migration[5][6].

✨

May reduce inflammation and fibrosis indirectly via thymosin pathways observed in animal models[11].

Protocol Reference

Protocol reference

Research Use Only. PeptiJournal supports private research documentation and calculation support. It does not provide medical advice, human-use directions, or claims of safety or effectiveness.

subcutaneousintramuscular

Commonly cited research range: 500–1000 mcg, daily.

Reference figures reported in the research literature — not a dosing recommendation. For interactive vial math and scheduling, see the Calculator and Schedule tabs.

Cited protocol & reconstitution guide

Source-backed reference fields by phase, including any volume fields authored in the cited guide.

Loading — twice weekly (weeks 1–2)

2–2.5 mg

Units / volume40–50 units (0.40–0.50 mL)

Maintenance — once weekly

2–2.5 mg

Units / volume40–50 units (0.40–0.50 mL)

Acute-injury window — every 2–3 days (2 weeks)

2–2.5 mg

Units / volume40–50 units (0.40–0.50 mL)

Acute-injury window — taper, once weekly

2–2.5 mg

Units / volume40–50 units (0.40–0.50 mL)

Phase	Reference amount	Units / volume
Loading — twice weekly (weeks 1–2)	2–2.5 mg	40–50 units (0.40–0.50 mL)
Maintenance — once weekly	2–2.5 mg	40–50 units (0.40–0.50 mL)
Acute-injury window — every 2–3 days (2 weeks)	2–2.5 mg	40–50 units (0.40–0.50 mL)
Acute-injury window — taper, once weekly	2–2.5 mg	40–50 units (0.40–0.50 mL)

Titration protocol

Loading — twice weekly (weeks 1–2)Start
2–2.5 mg per dose
Subcutaneous. Rotate injection sites.
Maintenance — once weeklyBuild
2–2.5 mg per dose
Subcutaneous. Rotate injection sites.
Acute-injury window — every 2–3 days (2 weeks)Build
2–2.5 mg per dose
Subcutaneous. Rotate injection sites.
Acute-injury window — taper, once weeklyMaintenance
2–2.5 mg per dose
Subcutaneous. Rotate injection sites.

Storage & Handling

Storage requirements(typical for most peptides)

❄️

Lyophilized (powder)

-20°C (frozen)

Can be stored for extended periods. Protect from moisture.

🧊

Reconstituted

2-8°C (refrigerated)

Store in refrigerator door. Never freeze after reconstitution.

⏱️

Stability window

28-30 days after reconstitution

Label vials with reconstitution date. Discard if cloudy.

Reconstitution steps

01🌡️Draw 1 mL bacteriostatic water into a sterile syringe — this 5 mg vial yields 5 mg/mL.
02🧴01 Inspect the vial — Confirm the label says TB-500, check the listed mass, and look for any cracks, contamination, or fluid in the powder vial.
03💉02 Wipe both stoppers — Use a fresh alcohol swab on the BAC-water stopper and the TB-500 vial stopper. Let the alcohol air dry before piercing.
04💧04 Inject the BAC water slowly — Insert the needle through the TB-500 vial stopper and let the BAC water run down the inside wall of the vial. Avoid forceful streams onto the powder, which can foam the peptide.
05🔄05 Swirl to dissolve — Gently swirl or roll the vial. Do not shake. The solution should be clear and colorless within a minute or two. If it looks cloudy, do not use it.
06🏷️06 Label and refrigerate — Write the reconstitution date on the vial. Store at 35.6-46.4 F (2-8 C). Use within 2-4 weeks; some references extend this to 30 days under proper refrigeration.
07❄️07 Draw the research dose — Use a fresh U-100 insulin syringe per session. Draw the planned volume, expel air bubbles, wipe the injection site, and inject subcutaneously. Rotate sites between sessions.
08💉Important: This guide is for educational purposes only and is not medical advice. For research use only. Not for human consumption.

Additional storage notes

Lyophilized (powder)

-4 F (-20 C) long-term — Refrigerator (35.6-46.4 F / 2-8 C) is acceptable for shorter-term storage; freezer is preferred for longer storage.

Reconstituted (liquid)

35.6-46.4 F (2-8 C) — Use within 2-4 weeks. Some references extend to 30 days under proper refrigeration.

In transit

Cool and dark — Brief exposure to ambient temperature is generally tolerated by lyophilized peptide; check supplier guidance for the specific product.

Light exposure

Avoid — Store both lyophilized and reconstituted vials in the original carton or a dark drawer of the refrigerator.

Clinical Evidence

Clinical evidence

Studies show enhanced healing of wounds, tendons, ligaments, and cardiac tissue. Reduces inflammation and scar tissue formation.

Full-length Tbeta-4, Phase 1 IV safety: Ruff et al. (2010), 40 healthy volunteers, single IV doses 42-1260 mg then daily x 14 days, no dose-limiting toxicities. Establishes that IV Tbeta-4 was tolerated short-term, not that the fragment is safe long-term subcutaneously. Full-length Tbeta-4, Phase 2 dermal wound (venous ulcers): Guarnera et al. (2010), 73 patients across 8 European sites, double-blind placebo-controlled topical 0.0001-0.03% Tbeta-4 over 12 weeks. Safety profile acceptable. About 25% complete healing in 3 months at the 0.03% dose, with stronger response in smaller wounds. Full-length Tbeta-4, Phase 2 pressure ulcer: RegeneRx-sponsored Phase 2 trial (NCT00382174) of topical 0.01-0.1% Tbeta-4. Acceleration of healing reported in patients who responded. Full-length Tbeta-4, Phase 3 ophthalmic (RGN-259): SEER-1 Phase 3 trial of 0.1% topical Tbeta-4 ophthalmic solution in neurotrophic keratopathy stages 2-3. Reported faster complete healing at 4 weeks vs. placebo, no safety issues. TB-500 fragment, preclinical only: The TB-500 fragment retains actin-binding behavior in cell-biology and in-vivo animal experiments. Specific human evidence for the fragment is absent. Cardiac preclinical: Bock-Marquette et al. (2004) showed Tbeta-4 reduces infarct volume and preserves cardiac function in mouse coronary ligation models. Subsequent work in mice and a porcine MI model has reported similar effects. No human cardiac endpoint trial has been completed for systemic Tbeta-4. Tendon and ligament preclinical: Kim & Bhatt (2013) reported improved collagen organization and fibril diameter at 4 weeks after fibrin-sealant Tbeta-4 delivery in a rat MCL transection model. No human trial. Evidence boundary: The widespread research-use claim that injectable TB-500 fragment 'heals tendons and ligaments in humans' is not supported by a published human RCT. It rests on extrapolation from preclinical full-length Tbeta-4 work.

01Identity (note ambiguity): 'TB-500' is a research-chemical designation commonly associated with thymosin beta-4 (Tu03b24) or an active fragment of it; exact identity and purity are supplier-dependent.
02In vitro / animal model: thymosin beta-4 is a naturally occurring actin-sequestering peptide involved in cell migration, with a research base spanning angiogenesis and tissue-repair processes.
03Animal model: studies report effects on dermal wound closure, corneal/ocular surface repair, and cardiac tissue repair after injury.
04In vitro: a short actin-binding motif (LKKTETQ) is frequently cited as central to cell-migration-related activity.
05Human study (early phase): thymosin beta-4 itself (not the 'TB-500' research product) has been evaluated in early human trials, e.g., dermal and ocular surface repair (RegeneRx clinical program).

Evidence maturity varies by compound; much peptide research is preclinical (in vitro or animal-model). Where human data are limited, findings should be read as research observations, not clinical conclusions.

References

Literature references

Published research articles and sources related to TB-500.

Search PubMed for TB-500

Observed Effects

Observed effects in cited research

Most commonly reported in research-use community

Mild injection-site discomfort, redness, and short-lived fatigue or head-pressure feelings in the first few days of a cycle.

Theoretical: cancer / unwanted angiogenesis

Tbeta-4 levels are elevated in some metastatic cancers and the peptide promotes angiogenesis. Whether sub-therapeutic injections of the fragment carry a meaningful risk in healthy adults has not been studied.

Theoretical: immune modulation

Tbeta-4 regulates inflammatory signaling. Long-term immune effects in repeated cycles are not characterized in humans.

Injection-site issues

Standard subcutaneous injection risks: local irritation, lipohypertrophy from poor site rotation, infection from poor technique.

Study and material context

Quality control risk

Research-use peptides are produced outside FDA-approved manufacturing pipelines. Purity, sterility, and identity vary between suppliers. A Certificate of Analysis specific to the lot is the minimum quality reference.

Research Considerations

Research considerations

Research peptide. Consult healthcare provider before use.

TB-500 is a research peptide with no FDA-approved clinical use. Decisions about personal use belong with a qualified clinician, not a research protocol page. The points below are general research-use boundaries, not a clinical eligibility list.
TB-500 and all thymosin beta-4 derivatives are explicitly prohibited by WADA under Section S0 (Non-Approved Substances), at all times. Detection windows are reported in the 30-45 day range. Athletes in WADA-tested sports, NCAA athletes, and military personnel under WADA-aligned testing should avoid use.
Tbeta-4 is associated with increased metastatic potential in some tumor models in the literature. This is a theoretical concern in active or prior cancer and is consistently flagged in research-use safety discussions, not a settled clinical risk.
There are no human data establishing safety in pregnancy or lactation. Avoid in those contexts.
Benzyl alcohol (the preservative in bacteriostatic water) can cause allergic reactions in a small number of users. Confirm tolerance before research-use protocols that involve repeated injections.
Standard injection-site cautions apply: do not inject into broken, infected, inflamed, or recently bruised skin.
TB-500 is not a treatment. People looking for clinical care for a wound, tendon injury, or cardiovascular condition should work with a clinician through approved care pathways.

Factors noted in the research literature; not patient-specific medical advice.

Regulatory Status

Regulatory status

RUO

Research Use Only. PeptiJournal supports private research documentation and calculation support. It does not provide medical advice, human-use directions, or claims of safety or effectiveness.

Comparisons

Compound	Mechanism	Route	Status
TB-500this	Upregulates actin, promotes cell migration, reduces inflammation, and stimulates wound healing and tissue repair.	subcutaneous, intramuscular	Investigational / RUO
BPC-157	Promotes angiogenesis, accelerates wound healing, and protects organs. Interacts with growth hormone receptors and NO system.	subcutaneous, intramuscular	Investigational / RUO
GHK-Cu	Stimulates collagen and glycosaminoglycan synthesis, promotes angiogenesis, and acts as antioxidant and anti-inflammatory agent.	subcutaneous, topical	Investigational / RUO
KPV	A C-terminal tripeptide fragment of alpha-melanocyte-stimulating hormone (Lys-Pro-Val) studied for anti-inflammatory activity, proposed to act through intracellular pathways (e.g., NF-kB modulation) without melanocortin pigmentary activity.	subcutaneous	Investigational / RUO
LL-37	The sole human cathelicidin-derived cationic antimicrobial peptide (37 residues), studied for broad-spectrum antimicrobial activity, immune modulation, and roles in wound healing and angiogenesis.	subcutaneous	Investigational / RUO
Tesamorelin	Binds to GHRH receptors to stimulate endogenous GH production. Preferentially reduces abdominal fat accumulation.	subcutaneous	Investigational / RUO
Testagen	A synthetic tetrapeptide bioregulator (Lys-Glu-Asp-Gly) studied for modulation of endocrine function, particularly pituitary-gonadal regulatory pathways.	subcutaneous	Investigational / RUO

Attributes shown for research comparison only; not a statement of efficacy or therapeutic equivalence.

Related Protocols

Healing4 tags

BPC-157

Body Protection Compound-157

A synthetic peptide derived from a protective protein found in the stomach. Known for its healing and regenerative properties.

Range: 250–500 mcg
Freq: daily
Cycle: 6 wk

Healing4 tags

GHK-Cu

Copper Peptide

A naturally occurring copper complex that promotes healing, collagen synthesis, and tissue remodeling.

Range: 1–3 mg
Freq: daily
Cycle: 8 wk

Healing

KPV

KPV (Lysine–Proline–Valine) is a C‑terminal tripeptide fragment of α‑melanocyte‑stimulating hormone (α‑MSH) studied for its potent anti‑inflammatory properties without melanotropic side effects[1][...

Range: 200–500 mcg
Freq: daily
Cycle: 12 wk

Healing

LL-37

LL-37 (also known as CAP-18) is a 37-amino-acid cationic antimicrobial peptide derived from the C-terminal of human cathelicidin (hCAP18)[1]. It is the only known human cathelicidin, exhibiting bro...

Range: 50–400 mcg
Freq: daily
Cycle: 16 wk

Growth Hormone3 tags

Tesamorelin

Growth Hormone Releasing Hormone Analog

A GHRH analog that specifically reduces visceral adipose tissue while increasing IGF-1.

Range: 1–2 mg
Freq: daily
Cycle: 12 wk

Longevity

Testagen

Testagen is a synthetic tetrapeptide with the sequence Lys‑Glu‑Asp‑Gly (KEDG), an anterior pituitary‑derived bioregulator studied for its role in modulating endocrine function, particularly the pit...

Range: 100–300 mcg
Freq: daily
Cycle: 16 wk

TB-500.

Calculated-volume support unavailable

Cited protocol & reconstitution guide

Reconstitution by vial size

Overview

Overview

Mechanism

TB-500

Mechanism of action

Key research findings

Pharmacokinetic profile

Researched Effects

Researched benefits

Protocol Reference

Protocol reference

Cited protocol & reconstitution guide

Titration protocol

Storage & Handling

Storage requirements(typical for most peptides)

Reconstitution steps

Additional storage notes

Clinical Evidence

Clinical evidence

References

Literature references

Observed Effects

Observed effects in cited research

Most commonly reported in research-use community

Theoretical: cancer / unwanted angiogenesis

Theoretical: immune modulation

Injection-site issues

Study and material context

Quality control risk

Research Considerations

Research considerations

Regulatory Status

Regulatory status

Comparisons

Comparisons

Related Protocols

BPC-157

GHK-Cu

KPV

LL-37

Tesamorelin

Testagen

FAQ

Frequently asked questions

Research-use notice