TB-500 is a synthetic peptide that replicates the active sequence of thymosin beta-4 (Tβ4), a 43-amino acid protein naturally present in virtually all human cells. It promotes tissue repair, reduces inflammation, accelerates injury recovery, and may improve tissue flexibility by supporting actin regulation and angiogenesis. Not FDA-approved; banned from 503A compounding pharmacies.

What is the difference between TB-500 and BPC-157?

TB-500 and BPC-157 are both research peptides studied for tissue healing but act through distinct mechanisms. TB-500 acts primarily through actin sequestration and endothelial cell migration, making it more systemic in its healing effects. BPC-157 acts more locally through growth factor signaling and NO modulation, with particular strength in gut healing. Many researchers combine both for synergistic tissue repair — they are compatible.

What is the typical TB-500 dose?

Research loading protocols commonly use 5 mg subcutaneously twice weekly for 4 weeks, followed by a maintenance phase of 2.5 mg once weekly. TB-500 is often cycled for 4–8 weeks per injury or protocol. These are research protocols only — not medical advice. TB-500 is not FDA-approved for any use.

Can you stack TB-500 with BPC-157?

TB-500 and BPC-157 are reported as compatible with potential synergistic healing effects in research contexts — they work through complementary mechanisms. BPC-157 provides local growth factor signaling and gut support; TB-500 provides systemic tissue repair via actin/angiogenesis pathways. However, there are no human clinical trials evaluating this combination. Consult a healthcare provider before combining peptides.

TB-500: Dosing, Side Effects & FDA Status

What is TB-500?

TB-500 is the active synthetic fragment of thymosin beta-4 (Tβ4), a 43-amino acid protein naturally present in virtually all human cells and critical to actin regulation, cell migration, and tissue regeneration. Research shows TB-500 promotes angiogenesis, reduces inflammation, improves tissue flexibility, and accelerates recovery from musculoskeletal injuries. Not FDA-approved; banned from 503A compounding pharmacies.

Mechanism of Action

Sequesters G-actin via thymosin β4 domain; promotes endothelial cell migration and angiogenesis; downregulates inflammatory cytokines (TNF-α, IL-1β); stimulates Wnt/β-catenin pathway

Target: G-actin, Wnt/β-catenin pathway, endothelial cells

Research / educational reference. Educational research index only — not medical advice. Literature maturity is not a verdict on whether a compound works in people. Community reports are not evidence of efficacy.

Evidence at a glance

Derived · maturity-1.0

Human efficacy is unproven unless an approved label or completed published efficacy program says otherwise. Counts reflect indexed literature volume/kind — never a verdict on effect.

Literature maturity

nascent 23/100

PubMed hits

CT.gov trials

Strong-human apps

Sample papers

Sample articles by era

pre-20182
2021-20231
2024-20262

Application grades (curated)

Human-grade apps0
Animal / in-vitro1
Mechanistic0

Does literature support studied applications?

Grades reflect cited literature posture — not a treatment recommendation. Community notes are never efficacy evidence.

Application	Cited evidence	Grade	Community
Tissue repair / actin-binding biology (preclinical)	Thymosin β4 fragment research focuses on cell migration and repair pathways in animals/cells.	Animal / in-vitro	Community reports vary; not evidence of efficacy.
Human clinical efficacy	Human efficacy remains unproven in completed published RCTs for common wellness claims.	Anecdotal only	Community reports vary; not evidence of efficacy.

Pharmacology

Mechanism of action

•Sequesters G-actin via thymosin β4 domain; promotes endothelial cell migration and angiogenesis; downregulates inflammatory cytokines (TNF-α, IL-1β); stimulates Wnt/β-catenin pathway
•Primary target framing: G-actin, Wnt/β-catenin pathway, endothelial cells

Half-life

~3 days

Identity & chemistry

CAS: 885340-08-9
PubChem: CID 62707662
Formula: C38H68N10O14
Molar mass: 889 Da
InChIKey: ADKDNDYYIZUVCZ-ZQNQAVPYSA-N

Identity cross-checked with PubChem where available. Compass HTML used only as a bootstrap checklist — not republished as product copy.

Storage & stability

Lyophilized: 2–8°C; lyophilized typical shelf 24+ months
Reconstituted: 2–8°C; in-use window often 28–45 days (product-dependent)
Tell-tale degradation: !Cloudiness, clumping, or particles after mixing
!Discoloration versus the expected clear/colorless (or labeled) solution
!Failed or incomplete reconstitution of lyophilized cake

Educational estimates. Prefer product labeling and peptide shelf-life tool.

Lab handling posture

Research / educational handling notes only. Not a substitute for an SDS.

•Use PPE appropriate for peptide powder/solution handling
•Avoid inhalation of lyophilized powder; handle spills per institutional policy
•Do not present research materials as medicines

Sample indexed literature

Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500, a product suspected to possess doping potential.
Drug testing and analysis · 2012 · PMID 22962027
Simultaneous quantification of TB-500 and its metabolites in in-vitro experiments and rats by UHPLC-Q-Exactive orbitrap MS/MS and their screening by wound healing activities in-vitro.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences · 2024 · PMID 38382158
TB500/TB1000 and SGF1000: A scientific approach for a better understanding of misbranded and adulterated drugs.
Drug testing and analysis · 2023 · PMID 36482504
Alkaline Phosphatase-Triggered Spatiotemporal Repair of Corneal Injury with TB500 Peptide Hydrogel.
ACS applied materials & interfaces · 2025 · PMID 41359360
Doping control analysis of TB-500, a synthetic version of an active region of thymosin β₄, in equine urine and plasma by liquid chromatography-mass spectrometry.
Journal of chromatography. A · 2012 · PMID 23084823

Research Indications

Tissue RepairMost Effective

Demonstrated acceleration of wound healing and soft tissue repair in research

Gut HealthEffective

Research shows beneficial effects on intestinal lining and GI function

Joint SupportEffective

Associated with reduced joint inflammation and improved mobility

Muscle RecoveryModerate

May support faster recovery from muscle strains and exercise stress

Research Protocols

These are commonly discussed research protocols — not medical advice. Consult a healthcare provider before use.

Goal	Dose	Frequency	Route
Loading Phase (Week 1–4)	5 mg	Twice weekly	Subcutaneous injection
Maintenance Phase (Week 5+)	2.5 mg	Once weekly	Subcutaneous injection
Acute Injury Protocol	5 mg	Twice weekly x 4 wks	Subcutaneous injection

Peptide & Drug Interactions

Always consult your healthcare provider before combining with other compounds. Use our Interaction Checker for reference.

TB-500 / BPC-157 (stack)Compatible

NSAIDs (Ibuprofen, Naproxen)Caution

CorticosteroidsCaution

AnticoagulantsMonitor

GH SecretagoguesCompatible

NAD+Compatible

How to Reconstitute & Inject

Use bacteriostatic (BAC) water only. Avoid saline — may cause precipitation. Refrigerate and use within 28 days.

1
Remove TB-500 vial from refrigeration and allow to reach room temperature (15–20 minutes)
2
Clean vial top with alcohol swab and allow to air dry completely
3
Using a sterile syringe, draw the calculated volume of bacteriostatic water (BAC water)
4
Inject BAC water slowly down the side of the vial — do not aim directly at the powder
5
Gently swirl in circular motions — DO NOT shake vigorously as this degrades the peptide
6
Allow 2–3 minutes for full dissolution — solution should be clear and colorless
7
Draw calculated dose into an insulin syringe for subcutaneous injection
8
Inject into abdomen, thigh, or upper arm. Rotate injection sites to prevent lipodystrophy
9
Store reconstituted solution refrigerated (2–8°C) and use within 28 days

What to Expect

Week 1–2

Initial anti-inflammatory effects begin. Reduced pain and swelling in target area.

Week 2–4

Improved tissue mobility and reduced discomfort. Early healing acceleration.

Week 4–8

Significant recovery milestones. Stronger tissue repair and functional improvement.

Week 8–12

Near-complete healing in many cases. Improved strength and tissue integrity.

Side Effects & Safety

Generally well-tolerated in research settings
Mild nausea with higher doses
Injection site redness or discomfort
Rare: Dizziness or lightheadedness
Potential effect on blood pressure (monitor if hypertensive)

TB-500 is not FDA-approved and cannot be prepared by 503A compounding pharmacies. PeptIQ does not sell peptides or list vendors. Talk with a licensed clinician.

FDA Status & Regulatory Info

Research Only

Rx Required: No

503A Ban: Yes

Telehealth: N/A

Full FDA Status Tracker

Frequently Asked Questions

Research References

External links for education only. We do not control third-party content.

Community-reported data

The information below reflects self-reported experiences from PeptIQ app users. It is not clinical evidence and should not replace professional medical advice.

Community Intelligence

What 103 users report

103 community reports

Overall experience

From check-in ratings — separate from side effects logged below. Side effects are logged separately from overall experience. A favorable check-in can still include nausea, fatigue, or injection-site reactions.

Favorable 38% · Mixed 62% · Unfavorable overall 0%

Most reported benefits

Benefits users selected when logging a favorable or mixed check-in.

Recovery

219

Most logged side effects

Side effects are logged separately from overall experience. A favorable check-in can still include nausea, fatigue, or injection-site reactions.

Headache

Fatigue

Self-reported dose per injection

Median bucket: 2–3 mg · Most common: 2–3 mg

Reports span 0 to ≥ 5 mg (open-ended top bucket)

0–0.01 mg

0.025–0.05 mg

0.1–0.2 mg

0.2–0.4 mg

0.4–0.6 mg

0.6–1 mg

1–2 mg

2–3 mg

3–5 mg

5+ mg

Anonymized self-reports from PeptIQ users — not prescribing guidance. Buckets group similar logged amounts; open-ended top buckets mean “at least” that dose.

Commonly stacked with

How repeat users are trending

Among repeat reporters, 57% said they felt similar to their last entry, 23% more positive, and 20% more negative.

Overall, repeat reporters leaned more positive than their previous entry.

Median gap between entries: 63 days · Based on 40 repeat reporters

Share Your Experience

Rate TB-500 in the PeptIQ app and help the community make informed decisions.

Download PeptIQ Google Play

Educational information only

This page is for educational reference. It is not medical or legal advice. PeptIQ does not sell peptides or list vendors. Consult the FDA and a licensed healthcare professional for current regulations and individualized guidance.

TB-500