TB-500 Dosage Guide: Loading Phase, Maintenance, Injection Protocol & Stacking (2026)
For educational purposes only. This content is not medical advice and does not diagnose, treat, cure, or prevent any disease. Always consult a licensed healthcare provider before beginning any peptide protocol.
TB-500 is a synthetic fragment of thymosin beta-4 (Tbeta4), a naturally occurring 43-amino-acid peptide present in virtually all human and animal cells. Thymosin beta-4 is one of the most abundant intracellular peptides in the body, playing a central role in cell migration, blood vessel formation, and tissue repair. TB-500 replicates the active region of this protein — specifically the actin-binding domain — making it one of the most researched peptides for recovery and healing applications.
TB-500 is the second most commonly used peptide in the DoseCraft community, appearing in 28% of all logged protocols — and over 65% of those are stacked with BPC-157.
This guide covers everything you need to know about TB-500 dosing: the science behind loading and maintenance phases, how to calculate your dose, injection technique, cycle length, stacking strategies, and the published research supporting its use.
How TB-500 Works: Mechanism of Action
TB-500 exerts its effects primarily through three mechanisms:
1. Actin Regulation (Evidence Tier: Clinical)
TB-500 upregulates the production of actin, a structural protein essential for cell motility. By increasing actin availability, TB-500 facilitates the migration of repair cells (fibroblasts, endothelial cells, keratinocytes) to damaged tissue. This is particularly significant for wound healing, where cell migration to the injury site is the rate-limiting step.
Citation-ready: Thymosin beta-4, the parent molecule of TB-500, is the primary intracellular actin-sequestering peptide in mammalian cells, regulating actin polymerization and enabling cell migration critical to wound repair processes.
2. Angiogenesis Promotion (Evidence Tier: Clinical)
Like BPC-157, TB-500 promotes the formation of new blood vessels. However, the mechanisms differ: while BPC-157 works primarily through VEGF upregulation, TB-500 promotes angiogenesis through direct endothelial cell migration and differentiation. The two pathways are complementary, which is why the BPC-157 + TB-500 stack is so widely used.
3. Anti-Inflammatory Activity (Evidence Tier: Clinical)
TB-500 has demonstrated anti-inflammatory properties in multiple research models, reducing inflammatory cytokine levels and modulating the inflammatory cascade. This dual action — promoting repair while reducing inflammation — makes it particularly relevant for injuries where chronic inflammation impedes healing.
4. Systemic Distribution (Evidence Tier: Expert)
Unlike some peptides that primarily exert local effects, TB-500 demonstrates systemic activity. Its low molecular weight and unique structure allow it to travel through tissues with high bioavailability after subcutaneous injection. This means injection site location is less critical for TB-500 than for locally-acting peptides.
Leading practitioners emphasize TB-500's systemic nature as its key differentiator — a single subcutaneous injection can influence repair processes throughout the body.
TB-500 Dosage Protocol
TB-500 dosing follows a distinct pattern: a loading phase to establish tissue saturation, followed by a lower maintenance phase. This approach is based on practitioner experience and the peptide's pharmacokinetic profile.
Loading Phase
| Parameter | Recommendation | Evidence Tier |
|---|---|---|
| Dose per injection | 2-2.5 mg | Expert |
| Frequency | 2x per week | Expert |
| Duration | 4-6 weeks | Expert |
| Total weekly dose | 4-5 mg | Expert |
Maintenance Phase
| Parameter | Recommendation | Evidence Tier |
|---|---|---|
| Dose per injection | 2-2.5 mg | Expert |
| Frequency | 1x per week or every 2 weeks | Expert |
| Duration | 4-8 weeks | Expert |
| Total weekly dose | 2-2.5 mg (or 1-1.25 mg biweekly avg) | Expert |
Weight-Based Dosing Reference
Some practitioners adjust TB-500 dosing by body weight:
| Body Weight | Loading Dose (25 mcg/kg) | Maintenance Dose (15 mcg/kg) |
|---|---|---|
| 60 kg (132 lbs) | 1,500 mcg (1.5 mg) | 900 mcg |
| 75 kg (165 lbs) | 1,875 mcg (1.88 mg) | 1,125 mcg |
| 90 kg (198 lbs) | 2,250 mcg (2.25 mg) | 1,350 mcg |
| 100 kg (220 lbs) | 2,500 mcg (2.5 mg) | 1,500 mcg |
Use the DoseCraft Calculator to convert these doses into exact syringe volumes based on your reconstitution.
How to Reconstitute and Inject TB-500
Step 1: Reconstitute the Vial
TB-500 typically comes in 5 mg or 10 mg lyophilized vials.
For a 5 mg vial:
- Add 2 mL of bacteriostatic water
- Concentration = 5,000 mcg / 2 mL = 2,500 mcg/mL
For a 10 mg vial:
- Add 2 mL of bacteriostatic water
- Concentration = 10,000 mcg / 2 mL = 5,000 mcg/mL
Direct the water stream against the vial wall. Do not shake — allow the peptide to dissolve naturally with gentle swirling if needed.
Step 2: Calculate Syringe Volume
For a 2.5 mg (2,500 mcg) dose from a 5 mg vial reconstituted with 2 mL:
2,500 mcg / 2,500 mcg/mL = 1.0 mL = 100 units on a 100-unit insulin syringe
Note: This is a full syringe. Many users prefer reconstituting with less water (e.g., 1 mL) to reduce injection volume:
2,500 mcg / 5,000 mcg/mL = 0.5 mL = 50 units
Step 3: Select Injection Site
Due to TB-500's systemic nature, injection site selection is less critical than with locally-acting peptides:
| Injection Site | Notes |
|---|---|
| Lower abdominal fat pad | Most common, easy access, consistent absorption |
| Outer thigh | Alternative site for rotation |
| Upper arm (tricep area) | Less common but viable |
| Near injury site | Optional — systemic action means location is secondary |
Step 4: Administer
- Clean site with alcohol swab
- Pinch skin, insert needle at 45-degree angle
- Inject slowly over 5-10 seconds
- Remove needle, apply gentle pressure
- Rotate sites between injections
Step 5: Storage
Store reconstituted TB-500 in the refrigerator (36-46degF / 2-8degC). Use within 28 days. Do not freeze.
TB-500 Cycle Structure
Standard Cycle Template
| Phase | Duration | Dose | Frequency | Purpose |
|---|---|---|---|---|
| Loading | Weeks 1-4 | 2-2.5 mg | 2x/week | Tissue saturation |
| Transition | Week 5 | 2-2.5 mg | 1x/week | Begin tapering |
| Maintenance | Weeks 6-12 | 2-2.5 mg | Every 1-2 weeks | Sustain effects |
| Off-cycle | 4-6 weeks | None | N/A | Receptor resensitization |
Cycle by Goal
| Goal | Loading Duration | Maintenance Duration | Total Cycle |
|---|---|---|---|
| Acute injury recovery | 4 weeks | 4 weeks | 8 weeks |
| Chronic injury / tendon | 6 weeks | 6-8 weeks | 12-14 weeks |
| General recovery support | 4 weeks | 4 weeks | 8 weeks |
| Post-surgical healing | 4-6 weeks | 4 weeks | 8-10 weeks |
Leading practitioners recommend reassessing at the end of the loading phase. If significant improvement is noted, transitioning to maintenance preserves gains while reducing compound usage. If improvement is minimal, extending the loading phase by 2 weeks before reassessing may be warranted.
Track your cycle progress with the DoseCraft Protocol Builder.
TB-500 Stacking Protocols
TB-500 + BPC-157 (The Healing Stack)
This is the most popular and well-documented peptide stack in the community. The synergy comes from complementary mechanisms:
- TB-500: Systemic — upregulates actin, promotes cell migration throughout the body
- BPC-157: Local + systemic — promotes angiogenesis via VEGF, local tissue repair
| Compound | Loading Dose | Loading Freq | Maintenance Dose | Maintenance Freq |
|---|---|---|---|---|
| TB-500 | 2-2.5 mg | 2x/week | 2-2.5 mg | 1x/week |
| BPC-157 | 250-500 mcg | 2x/day | 250 mcg | 1-2x/day |
Evidence tier: Expert (widely practitioner-endorsed)
This stack is detailed in the DoseCraft Stacking Guide.
TB-500 + GHK-Cu (Tissue Regeneration Stack)
For deep tissue repair and collagen remodeling:
| Compound | Dose | Frequency |
|---|---|---|
| TB-500 | 2 mg | 2x/week |
| GHK-Cu | 200-600 mcg | Daily |
Evidence tier: Experimental
TB-500 + Pentosan Polysulfate (Joint Stack)
For joint and cartilage support:
| Compound | Dose | Frequency |
|---|---|---|
| TB-500 | 2 mg | 2x/week |
| Pentosan | Per practitioner guidance | Weekly |
Evidence tier: Experimental
TB-500 vs. Thymosin Beta-4: What's the Difference?
A common source of confusion:
| Feature | TB-500 | Thymosin Beta-4 (Tbeta4) |
|---|---|---|
| Length | 43 amino acids (same as Tbeta4) | 43 amino acids |
| Origin | Synthetic | Endogenous (naturally produced) |
| Active region | Contains the actin-binding domain | Contains the actin-binding domain |
| Availability | Research peptide suppliers | Less commonly available |
| Naming | Often used interchangeably | The parent molecule |
| Research | Extensive (by both names) | Extensive |
In practice, TB-500 and thymosin beta-4 are used interchangeably in most protocols. TB-500 is technically a synthetic version of the full Tbeta4 sequence, with the active actin-binding region intact.
TB-500 Research Evidence
Published Research Summary
| Research Area | Key Finding | Species | Evidence Tier |
|---|---|---|---|
| Cardiac repair | Reduced infarct size, improved cardiac function | Mouse | Clinical |
| Wound healing | Accelerated wound closure, increased angiogenesis | Mouse/Rat | Clinical |
| Corneal repair | Enhanced corneal wound healing | Rat | Clinical |
| Dermal repair | Improved keratinocyte migration | In vitro | Clinical |
| Hair growth | Stimulated hair follicle stem cell migration | Mouse | Clinical |
| Neuroprotection | Reduced brain damage after stroke | Rat | Clinical |
| Tendon repair | Improved tendon healing markers | Rat | Clinical |
Key Research Citations
- Thymosin beta-4 has been demonstrated to activate cardiac progenitor cells, promote angiogenesis, and reduce scar formation following myocardial infarction in rodent models. (Circulation Research)
- In dermal wound models, thymosin beta-4 increased the rate of wound closure by 40-50% compared to controls, primarily through enhanced keratinocyte and endothelial cell migration. (FASEB Journal)
Important: As with most peptide research, the majority of published TB-500/Tbeta4 studies are in animal models. Human clinical trials are limited but ongoing.
Potential Side Effects
Commonly Reported (from community data and clinical literature)
| Side Effect | Frequency | Severity | Management |
|---|---|---|---|
| Injection site redness | Common | Mild | Resolves in hours |
| Temporary lethargy | Occasional | Mild | Usually subsides after 1-2 weeks |
| Head rush after injection | Occasional | Mild | Inject slowly, remain seated |
| Mild headache | Uncommon | Mild | Hydration, acetaminophen |
Safety Considerations
- Cancer history: Like BPC-157, TB-500 promotes angiogenesis. Individuals with active cancer or cancer history should consult an oncologist before use.
- Pregnancy/breastfeeding: No safety data. Avoid.
- Equine regulation: TB-500 is banned in horse racing due to its healing properties. This is relevant only to equine contexts but demonstrates its recognized biological activity.
Vial Planning and Cost Analysis
Vials Needed Per Cycle
| Protocol | Weekly Dose | Duration | Total Needed | 5 mg Vials Required |
|---|---|---|---|---|
| Loading only | 5 mg | 4 weeks | 20 mg | 4 |
| Loading + maintenance | 5 mg + 2.5 mg | 4 + 4 weeks | 30 mg | 6 |
| Extended cycle | 5 mg + 2.5 mg | 6 + 6 weeks | 45 mg | 9 |
Cost Estimates
| Vial Source Tier | Price per 5 mg | 4-Week Loading | Full 8-Week Cycle |
|---|---|---|---|
| Budget | $25-35 | $100-140 | $150-210 |
| Mid-range | $35-50 | $140-200 | $210-300 |
| Premium | $50-75 | $200-300 | $300-450 |
Frequently Asked Questions
What is the standard TB-500 dosage?
The standard TB-500 dosage is 2-2.5 mg per injection during loading (twice weekly for 4-6 weeks) and 2-2.5 mg once weekly or every two weeks during maintenance. Total weekly loading dose is typically 4-5 mg. These ranges are based on leading practitioner protocols and community consensus.
How long does TB-500 take to work?
Most users report initial improvements within 1-2 weeks of starting the loading phase. More significant results typically emerge during weeks 3-6. The full benefit of a loading + maintenance cycle becomes apparent over the 8-12 week protocol timeline.
Do I need a loading phase for TB-500?
Yes. The loading phase is a core component of TB-500 protocols. Higher-frequency dosing during the first 4-6 weeks establishes tissue saturation, after which maintenance dosing sustains the effects. Skipping the loading phase and going directly to weekly dosing may produce suboptimal results.
Can I inject TB-500 anywhere?
Due to its systemic distribution properties, TB-500 can be injected subcutaneously at any standard site — abdomen, thigh, or upper arm. Unlike BPC-157, proximity to the injury site is less critical because TB-500 acts systemically. Most practitioners recommend the lower abdominal fat pad for consistency.
How does TB-500 differ from BPC-157?
TB-500 works primarily through actin upregulation and cell migration promotion, acting systemically throughout the body. BPC-157 works primarily through VEGF-mediated angiogenesis and has stronger local effects at the injection site. TB-500 is dosed at milligram levels 2x weekly, while BPC-157 is dosed at microgram levels 1-2x daily. The two are highly complementary, which is why they are frequently stacked together.
Should I stack TB-500 with BPC-157?
The BPC-157 + TB-500 stack is the most popular and well-documented peptide combination. Their complementary mechanisms — BPC-157's local angiogenesis and TB-500's systemic cell migration — create a synergy that has made this stack the go-to healing protocol for experienced peptide users. See the DoseCraft Stacking Guide for detailed protocols.
Is TB-500 legal?
TB-500 is sold as a research peptide and is not approved by the FDA for human medical use. It is banned in certain competitive sports contexts (e.g., equine racing, some athletic organizations). Legal status varies by jurisdiction. Research the regulations in your area before purchasing.
How should I store TB-500?
Lyophilized (powder) TB-500 should be stored at room temperature or refrigerated. Once reconstituted with bacteriostatic water, store in the refrigerator (36-46degF) and use within 28 days. Do not freeze reconstituted peptides.
Build Your TB-500 Protocol
Ready to plan your cycle? The DoseCraft Protocol Builder lets you configure loading and maintenance phases with automatic dose calculations. Explore the full TB-500 compound profile in the DoseCraft Library, or use the Calculator to verify your syringe measurements.
For educational purposes only. This content has not been evaluated by the FDA and is not intended to diagnose, treat, cure, or prevent any disease. Consult a qualified healthcare professional before beginning any peptide protocol.