TB-500 Dosage Guide: Complete Loading, Maintenance & Cycle Protocol (2026)
Not medical advice — educational only. This content has not been evaluated by the FDA and is not intended to diagnose, treat, cure, or prevent any disease. Always consult a licensed healthcare provider before beginning any peptide protocol.
TB-500 (Thymosin Beta-4) is a 43-amino-acid peptide that plays a central role in tissue repair, cell migration, and new blood vessel formation. Unlike many peptides that act primarily at the injection site, TB-500 has a systemic distribution profile — meaning it can exert healing effects throughout the entire body regardless of where it is injected. This unique characteristic, combined with its relatively long half-life, creates a dosing paradigm that differs significantly from shorter-acting peptides like BPC-157.
Getting the TB-500 dosage right requires understanding its biphasic dosing structure: a higher-dose loading phase followed by a reduced maintenance phase. This guide provides the complete framework for TB-500 dosing based on clinical evidence, expert practitioner protocols, and documented experimental outcomes.
TB-500 Mechanism of Action and Dosing Implications
TB-500 primary mechanism involves upregulating actin, a protein critical for cell structure, movement, and tissue repair. By increasing cellular actin levels, TB-500 promotes cell migration (cells move to injury sites faster), angiogenesis (new blood vessel formation improves nutrient delivery to damaged tissue), anti-inflammation (reduces inflammatory markers at injury sites), and extracellular matrix remodeling (supports connective tissue rebuilding).
These mechanisms are dose-dependent — meaning you need to reach a sufficient tissue concentration before meaningful healing effects occur. This is why TB-500 protocols use a loading phase: to rapidly achieve therapeutic tissue levels before transitioning to a lower maintenance dose.
TB-500 Dosage Ranges: Evidence-Tiered
| Evidence Tier | Loading Phase (per injection) | Maintenance Phase (per injection) | Frequency |
|---|---|---|---|
| Clinical (animal-model extrapolated) | 2.0-2.5 mg | 1.0-2.0 mg | 2x/week loading, 1x/week maintenance |
| Expert (practitioner-recommended) | 2.5 mg | 2.0-2.5 mg | 2x/week loading, 1x/week or biweekly maintenance |
| Experimental (advanced community) | 5.0 mg | 2.5 mg | 2x/week loading, 1x/week maintenance |
Key Dosing Distinction: Milligrams, Not Micrograms
Unlike BPC-157 (dosed in micrograms), TB-500 is dosed in milligrams. This is a critical distinction — confusing mg and mcg is a common and potentially significant error. Always verify your units.
| Peptide | Dose Unit | Typical Single Dose |
|---|---|---|
| BPC-157 | Micrograms (mcg) | 250-500 mcg |
| TB-500 | Milligrams (mg) | 2.0-5.0 mg |
Loading Phase Protocol
The loading phase is designed to rapidly build tissue-level concentrations of TB-500. Without adequate loading, the maintenance phase may not sustain sufficient levels for optimal healing.
Standard Loading Protocol
| Parameter | Value |
|---|---|
| Dose per injection | 2.5 mg |
| Frequency | 2x per week (e.g., Monday and Thursday) |
| Duration | 4-6 weeks |
| Total weekly dose | 5.0 mg |
| Total loading dose (4 weeks) | 20 mg |
| Total loading dose (6 weeks) | 30 mg |
Loading Phase Dosing Schedule Example
| Week | Monday | Thursday | Weekly Total |
|---|---|---|---|
| 1 | 2.5 mg | 2.5 mg | 5.0 mg |
| 2 | 2.5 mg | 2.5 mg | 5.0 mg |
| 3 | 2.5 mg | 2.5 mg | 5.0 mg |
| 4 | 2.5 mg | 2.5 mg | 5.0 mg |
After completing 4 weeks of loading, transition to maintenance.
Maintenance Phase Protocol
The maintenance phase sustains the tissue concentrations established during loading with reduced dosing frequency.
Standard Maintenance Protocol
| Parameter | Value |
|---|---|
| Dose per injection | 2.0-2.5 mg |
| Frequency | 1x per week |
| Duration | 4-8 weeks (or as needed) |
| Total weekly dose | 2.0-2.5 mg |
Extended Maintenance
Some leading practitioners advocate for extended maintenance periods at lower frequencies:
| Duration | Frequency | Dose | Use Case |
|---|---|---|---|
| 4 weeks | 1x/week | 2.5 mg | Standard post-loading maintenance |
| 8 weeks | 1x/week | 2.0 mg | Chronic injury, slow-healing tissue |
| 12+ weeks | 1x biweekly | 2.5 mg | Long-term tissue support (advanced) |
Complete TB-500 Cycle Architecture
Standard Cycle (12 Weeks Total)
| Phase | Weeks | Dose | Frequency | Purpose |
|---|---|---|---|---|
| Loading | 1-4 | 2.5 mg | 2x/week | Build tissue concentration |
| Maintenance | 5-8 | 2.5 mg | 1x/week | Sustain healing |
| Off-cycle | 9-12 | None | — | Receptor resensitization |
Aggressive Cycle (16 Weeks Total)
| Phase | Weeks | Dose | Frequency | Purpose |
|---|---|---|---|---|
| Loading | 1-6 | 2.5 mg | 2x/week | Extended saturation |
| High maintenance | 7-10 | 2.5 mg | 1x/week | Sustained high levels |
| Low maintenance | 11-12 | 2.0 mg | 1x/biweekly | Gradual taper |
| Off-cycle | 13-16 | None | — | Full reset |
Configure your exact cycle structure in the DoseCraft Protocol Builder.
Reconstitution and Dose Calculation
TB-500 is typically sold as a lyophilized powder in 2 mg or 5 mg vials.
Reconstitution Table
| Vial Size | BAC Water | Concentration | 2.0 mg = | 2.5 mg = | 5.0 mg = |
|---|---|---|---|---|---|
| 2 mg | 1 mL | 2 mg/mL | 100 units (full syringe) | N/A | N/A |
| 5 mg | 1 mL | 5 mg/mL | 40 units | 50 units | 100 units |
| 5 mg | 2 mL | 2.5 mg/mL | 80 units | 100 units | N/A |
| 5 mg | 0.5 mL | 10 mg/mL | 20 units | 25 units | 50 units |
Practical tip: For 2.5 mg doses from a 5 mg vial, reconstituting with 1 mL BAC water gives 50 units per dose — easy to measure accurately. Use the DoseCraft Calculator for instant calculations.
Injection Protocol
Subcutaneous Administration (Preferred)
- Needle: 29-31 gauge, 1/2 inch insulin syringe
- Sites: Abdominal fat (most common), upper thigh, back of arm
- Technique: Pinch skin, insert at 45-degree angle, inject slowly, release
Injection Site Considerations
Because TB-500 distributes systemically, the injection site matters less than with locally-acting peptides. However, site rotation remains important. Rotate between at least 4 sites, avoid injecting the same site more than once per week, and use abdominal quadrant rotation as the simplest system. Track sites in the DoseCraft app to prevent repetition.
TB-500 Stacking Protocols
TB-500 + BPC-157 (Gold Standard Healing Stack)
The synergy between TB-500 systemic cell migration and BPC-157 local angiogenesis makes this the most widely documented peptide combination.
| Compound | Loading Dose | Maintenance Dose | Frequency |
|---|---|---|---|
| TB-500 | 2.5 mg | 2.5 mg | 2x/week loading, 1x/week maintenance |
| BPC-157 | 500 mcg | 250 mcg | 2x/day throughout |
TB-500 + GHK-Cu (Tissue Remodeling Stack)
| Compound | Dose | Frequency | Target |
|---|---|---|---|
| TB-500 | 2.5 mg | 2x/week | Systemic repair |
| GHK-Cu | 200 mcg | 1x/day SubQ | Collagen synthesis, skin/tissue quality |
Explore stacking options in the DoseCraft Library.
Monitoring and Safety
What to Track
- Weekly progress measurements (pain scale, range of motion, functional capacity)
- Injection times, doses, and sites
- Any side effects (headache, nausea, lightheadedness, injection site redness)
- Bloodwork markers at baseline, mid-cycle, and post-cycle
Bloodwork Panel
| Marker | Purpose | Timing |
|---|---|---|
| CRP | Inflammation tracking | Pre, mid, post |
| CBC | General health | Pre, post |
| Liver enzymes (AST/ALT) | Safety monitoring | Pre, post |
| IGF-1 | Growth factor assessment | Pre, post |
Known Side Effects
TB-500 is generally well-tolerated. Reported side effects from community and clinical data include temporary head rush or lightheadedness after injection (common, transient), mild headache (infrequent), injection site redness or irritation (rare with proper technique), temporary fatigue (infrequent), and nausea (rare).
Vial Quantity Planning
| Protocol Phase | Duration | Weekly Dose | Total Dose | 5 mg Vials Needed |
|---|---|---|---|---|
| Loading (4 weeks) | 4 weeks | 5.0 mg | 20 mg | 4 |
| Maintenance (4 weeks) | 4 weeks | 2.5 mg | 10 mg | 2 |
| Full 8-week cycle | 8 weeks | — | 30 mg | 6 |
Plan your vial inventory upfront to avoid interrupting your protocol mid-cycle. The DoseCraft Protocol Builder calculates this automatically.
Common TB-500 Dosing Mistakes
| Mistake | Consequence | Solution |
|---|---|---|
| Skipping loading phase | Never reaches therapeutic tissue levels | Follow full 4-week loading protocol |
| Confusing mg with mcg | 1000x dosing error | Always verify units on vial label |
| Injecting same site repeatedly | Tissue irritation, lipodystrophy | Rotate sites using 4+ positions |
| Too short off-cycle | Receptor desensitization | Minimum 4-week break between cycles |
| Not tracking doses | Cannot assess protocol effectiveness | Log every injection in DoseCraft |
| Shaking vial during reconstitution | Denatures peptide | Swirl gently, never shake |
Frequently Asked Questions
What is the standard TB-500 dosage?
The most widely recommended TB-500 dosage is 2.5 mg injected subcutaneously twice per week during the loading phase (4-6 weeks), followed by 2.0-2.5 mg once per week during maintenance (4-8 weeks). This protocol is endorsed by multiple leading practitioners based on clinical observation and experimental data.
How long does TB-500 take to work?
Most users report initial effects within 1-2 weeks of beginning the loading phase, with significant improvements becoming apparent by weeks 3-4. Full benefits typically manifest over the complete 8-12 week cycle. Individual response varies based on injury severity, overall health, and protocol compliance.
Can I inject TB-500 anywhere on my body?
Yes. Unlike BPC-157, which has stronger local effects, TB-500 distributes systemically regardless of injection site. Subcutaneous abdominal injections are most common due to convenience. Some practitioners recommend occasional injection near the primary injury site, but systemic distribution means any SubQ site is effective.
Is TB-500 the same as Thymosin Beta-4?
TB-500 is a synthetic version of the active region of Thymosin Beta-4 (TB4), a naturally occurring 43-amino-acid peptide. They are functionally similar, though full-length TB4 and the TB-500 fragment may have slight pharmacological differences. In practical use, the terms are often used interchangeably.
How should I store TB-500?
Store lyophilized (powder) TB-500 refrigerated or at controlled room temperature. Once reconstituted with bacteriostatic water, store in the refrigerator (36-46 degrees F / 2-8 degrees C) and use within 28 days. Never freeze reconstituted peptide solutions.
Can I take TB-500 and BPC-157 in the same syringe?
Some practitioners report combining both peptides in the same syringe for convenience. However, there is limited formal data on stability when mixed. The conservative approach is to administer them in separate injections. Consult the DoseCraft stacking guide for detailed combination protocols.
Plan Your TB-500 Protocol
Design your complete loading and maintenance protocol with the DoseCraft Protocol Builder. Review the full TB-500 compound profile for evidence-tiered dosing data, or calculate your exact syringe measurements with the DoseCraft Calculator.
Not medical advice — educational 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.