TB-500 Dosing Guide: Protocols & Stacks (2026)
TB-500 dosing guide with protocols, Thymosin Beta-4 clinical data, healing mechanisms, BPC-157 stacking, and safety.
TB-500 is a synthetic 17-amino-acid fragment of Thymosin Beta-4, containing the active actin-binding domain responsible for cell migration and tissue repair. It's become a cornerstone of healing peptide protocols, especially when stacked with BPC-157.
Clinical Status: No human trials exist for TB-500 specifically. All protocols are extrapolated from Thymosin Beta-4 research and animal studies. This is not medical advice.
Quick Reference: Community Dosing
If you're here for the practical protocol, here it is:
| Parameter | Standard Protocol |
|---|---|
| Dose | 500 mcg daily |
| Route | Subcutaneous injection (systemic — site doesn't matter) |
| Timing | Morning injections preferred |
| Cycle | 8 weeks on, 8 weeks off |
| Injection site | Anywhere (abdomen, thigh, arm) |
| Vial size | 5 mg or 10 mg |
| Reconstitution | 2 mL bacteriostatic water per 5 mg vial |
| Storage | Refrigerate, use within 28 days |
Most people run 500 mcg daily for 8 weeks. TB-500 works systemically, so injection site location doesn't affect efficacy. For detailed stacking with BPC-157, see the Stacking TB-500 section below.
For the full TB-500 peptide profile, vendor pricing, and comparison with full TB-4, see our TB-500 peptide page.
Loading vs Maintenance
Unlike some peptides, TB-500 protocols typically use consistent daily dosing throughout the cycle:
Standard Protocol (Weeks 1-8): 500 mcg daily — this maintains steady tissue levels for optimal cell migration and actin remodeling effects.
Alternative Pulsing Protocol: Some users dose 2-2.5 mg twice weekly (mimicking TB-4 research protocols). This provides similar weekly totals with less frequent injections but may result in more variable tissue levels.
The daily protocol is more popular because TB-500's half-life supports once-daily dosing, and consistent levels optimize the cellular repair processes it targets (Kim & Bhatt, 2013).
Typical Protocol Lengths
- Acute injury recovery: 6-8 weeks
- Chronic injury / tissue repair: 8-12 weeks
- Post-surgical healing: 4-6 weeks starting 1-2 weeks post-surgery
- Athletic recovery / longevity: 8 weeks on, 8 weeks off (cycling)
Routes of Administration
Subcutaneous Injection (Standard Route)
The primary route for community protocols. TB-500 is systemic — inject anywhere convenient.
- Injection sites — Abdomen, thigh, upper arm. Site doesn't affect efficacy since TB-500 distributes systemically
- Needle — 29-31 gauge insulin syringe
- Volume — Typically 0.2 mL (20 units) for standard 500 mcg dose
- Timing — Morning preferred to align with natural healing cycles
Intramuscular
Occasionally used but offers no advantage over subcutaneous. IM injections are more painful with no increased efficacy for systemic peptides like TB-500.
Not Recommended Routes
- Oral — Peptide degradation makes this ineffective
- Nasal — No established protocols or absorption data
- Topical — Molecular weight too large for skin penetration
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Where These Numbers Come From: Clinical Context
Community TB-500 dosing is extrapolated from Thymosin Beta-4 research, adjusted for molecular weight differences.
Thymosin Beta-4 Clinical Data
Phase I Human Safety (Ruff et al., 2010):
- IV doses up to 1,260 mg well-tolerated in healthy subjects
- No dose-limiting toxicities identified
- Linear pharmacokinetics across dose range
Animal Efficacy Studies:
- Standard research dose: 6-30 mg/kg in rodents for healing studies
- Cardiac protection: 6 mg/kg IV twice weekly (Bock-Marquette et al., 2004)
- Wound healing: 2-10 mg/week typical range in various models
Scaling TB-4 Data to TB-500
TB-500 is the 17-23 amino acid fragment (~845 Da) of full Thymosin Beta-4 (~4,921 Da):
| Molecule | Molecular Weight | Relative Size |
|---|---|---|
| Thymosin Beta-4 | 4,921 Da | 100% |
| TB-500 fragment | 845 Da | ~17% |
Community scaling logic:
- If TB-4 protocols use 2-10 mg/week and TB-500 contains the primary active domain at ~17% molecular weight
- Pro-rata scaling: 2-10 mg × 0.17 = 0.34-1.7 mg/week
- Community settled on 3.5 mg/week (500 mcg daily × 7 days) — middle of this range
Why This Approach Makes Sense
The 17-23 sequence contains the critical LKKTET motif responsible for actin binding and cell migration (Malinda et al., 1999). While full TB-4 has additional sequences, the TB-500 fragment captures the core mechanism at a fraction of the cost.
Reconstitution Guide
TB-500 comes as lyophilized powder requiring reconstitution with bacteriostatic water.
What You Need
- TB-500 vial (5 mg or 10 mg)
- Bacteriostatic water (BAC water) — 0.9% benzyl alcohol preservative
- Insulin syringes (29-31 gauge)
- Alcohol swabs
Steps
- Sanitize both vial stoppers with alcohol swabs
- Draw 2 mL of BAC water into syringe
- Inject slowly into TB-500 vial — aim for glass wall to avoid foaming
- Swirl gently until completely dissolved (1-3 minutes)
- Label with date and concentration
Dosing Math
| Vial Size | BAC Water | Concentration | 500 mcg Dose |
|---|---|---|---|
| 5 mg | 2 mL | 2,500 mcg/mL | 20 units |
| 5 mg | 1 mL | 5,000 mcg/mL | 10 units |
| 10 mg | 2 mL | 5,000 mcg/mL | 10 units |
2 mL into 5 mg vial gives convenient math: 500 mcg = 20 units on insulin syringe.
Storage
- Refrigerate immediately (2-8°C / 36-46°F)
- Use within 28 days after reconstitution
- Don't freeze reconstituted solution
- Light sensitive — store in original packaging or wrap in foil
- Lyophilized powder stable frozen (-20°C) for extended periods
Mechanism of Action
TB-500 works primarily through actin regulation and cell migration — different from the growth factor pathways targeted by BPC-157:
Actin-Binding Domain — The LKKTET sequence binds to G-actin, preventing polymerization into F-actin filaments. This allows cells to reorganize their cytoskeleton for migration to injury sites (Malinda et al., 1999).
Cell Migration — Promotes migration of endothelial cells, keratinocytes, and fibroblasts to sites of tissue damage. Critical for wound closure and tissue repair phases (Kim & Bhatt, 2013).
Anti-Fibrotic Effects — Reduces excessive collagen deposition and scar formation by modulating fibroblast activity. This leads to improved tissue quality during healing.
Angiogenesis Support — While not as direct as BPC-157, TB-500 supports new blood vessel formation through endothelial cell migration and organization.
Anti-Inflammatory Modulation — Reduces inflammatory cytokines in acute injury models, helping transition from inflammatory to proliferative healing phases (Bock-Marquette et al., 2004).
Stem Cell Activation — May enhance mobilization and activity of various stem cell populations involved in tissue repair.
Side Effects & Safety
TB-500 safety data is limited since no direct human trials exist, but community experience has been largely positive.
What Animal Studies Show
Thymosin Beta-4 Safety (Ruff et al., 2010):
- No serious adverse events in Phase I human study (up to 1,260 mg IV)
- No dose-limiting toxicities identified
- Well-tolerated across wide dose range
Animal Toxicology:
- No significant toxicity in rodent studies at therapeutic doses
- No organ damage or systemic toxicity
- No carcinogenic potential identified in available studies
What the Community Reports
Most users report minimal side effects with TB-500:
Common (but mild):
- Injection site irritation or redness
- Mild fatigue during first week of use
- Transient muscle/joint aches as healing ramps up
- Occasional headaches (uncommon)
Less Common:
- Mild nausea (rare)
- Temporary sleep disruption
- Changes in energy levels (usually positive)
Theoretical Concerns
Limited Human Data — TB-500 specifically has no direct human trials, making long-term safety profiles unknown.
Actin System Effects — Chronic actin manipulation could theoretically affect cellular processes beyond healing, though no negative effects have been documented.
Cancer Considerations — Like BPC-157, TB-500 promotes cell migration. While no studies show tumor promotion, this remains a theoretical concern for individuals with existing cancers.
Stacking TB-500
TB-500 works exceptionally well in combination with other healing peptides due to its unique mechanism.
TB-500 + BPC-157 (The Gold Standard Healing Stack)
The most popular and well-regarded healing peptide combination. They target different but complementary pathways:
Why They Work Together:
- BPC-157 → Angiogenesis, growth factor upregulation, GI protection
- TB-500 → Cell migration, actin remodeling, anti-fibrotic effects
| Peptide | Dose | Route | Timing |
|---|---|---|---|
| TB-500 | 500 mcg daily | SC (anywhere) | Morning |
| BPC-157 | 250-500 mcg daily | SC (near injury) | Morning or evening |
Protocol Length: 8 weeks on, 8 weeks off for both peptides.
TB-500 + Thymosin Beta-4 (Full Spectrum)
For users wanting maximum healing potential, some combine TB-500 (the fragment) with full Thymosin Beta-4:
| Peptide | Dose | Frequency |
|---|---|---|
| TB-500 | 500 mcg | Daily |
| TB-4 (full) | 2-5 mg | 2x weekly |
This provides the rapid-acting TB-500 fragment plus the additional signaling domains present in full TB-4.
TB-500 + GHK-Cu
GHK-Cu handles collagen synthesis and remodeling. Pairs well with TB-500's cell migration effects:
- TB-500: 500 mcg daily SC
- GHK-Cu: 1-3 mg 2x weekly SC
Good for protocols targeting skin healing, anti-aging, or cosmetic recovery.
Stacking Tips
- Start one peptide at a time to assess individual response
- Use separate injection sites when combining peptides
- TB-500 can be injected anywhere (systemic effect)
- Most healing stacks run 8-week cycles with 8-week breaks
Frequently Asked Questions
What is the standard TB-500 dose?
The most common community protocol is 500 mcg daily via subcutaneous injection. This is extrapolated from Thymosin Beta-4 animal studies, scaled down for the smaller TB-500 fragment molecular weight.
Does injection site matter with TB-500?
No — TB-500 works systemically regardless of injection site. Unlike BPC-157 where some people inject near injuries, TB-500 circulates throughout the body. Inject wherever is convenient: abdomen, thigh, or arm.
How does TB-500 differ from full Thymosin Beta-4?
TB-500 is the active 17-23 amino acid fragment containing the key LKKTET actin-binding domain. Full TB-4 has 43 amino acids with additional signaling sequences. TB-500 captures most healing effects at a fraction of the cost.
How long should a TB-500 cycle last?
Most protocols run 8 weeks on, 8 weeks off. Tissue remodeling effects build over 4-6 weeks and continue through 8 weeks. Cycling prevents potential receptor downregulation and maintains long-term effectiveness.
Are there human clinical trials for TB-500?
No direct human trials exist for TB-500 specifically. However, the parent molecule Thymosin Beta-4 has Phase I safety data showing IV doses up to 1,260mg were well-tolerated in healthy subjects with no serious adverse events.
Can TB-500 and BPC-157 be taken together?
Yes — this is the most popular healing peptide combination. They work through different mechanisms (TB-500: cell migration and actin remodeling; BPC-157: angiogenesis and growth factors) and are highly complementary for tissue repair.
What are the side effects of TB-500?
Community reports are mostly positive — occasional injection site irritation, mild fatigue during the first week, or transient joint aches as healing processes ramp up. No significant toxicity has been reported, though long-term human data is limited.
How do I reconstitute TB-500?
Add 2 mL of bacteriostatic water to a 5 mg vial for 2,500 mcg/mL concentration. A 500 mcg dose equals 20 units on an insulin syringe. Swirl gently until dissolved, refrigerate, and use within 28 days.
Related Guides
- TB-500 Peptide Page — Vendor pricing, full peptide profile, and detailed comparisons
- TB-500 vs Thymosin Beta-4 — Fragment vs full-length molecule comparison
- Wolverine Stack BPC-157 TB-500 — The ultimate healing peptide combination
- Thymosin Beta-4 Benefits — Full-length TB-4 peptide profile
- Thymosin Beta-4 Injury Recovery — Specific injury protocols
References
| Citation | Topic | PMID |
|---|---|---|
| Ruff et al., Wound Repair Regen (2010) | Thymosin Beta-4 Phase I human safety, IV doses up to 1,260mg | 20536472 |
| Malinda et al., Proc Natl Acad Sci (1999) | TB-500 actin-binding domain, LKKTET sequence mechanism | 10469335 |
| Bock-Marquette et al., Nature (2004) | Thymosin Beta-4 cardiac protection, 6 mg/kg dosing in mice | 15565145 |
| Kim & Bhatt, Annu Rev Med (2013) | TB-500 mechanisms, cell migration, tissue repair review | 23523891 |
| Philp et al., J Cell Sci (2004) | Actin sequestration and cell motility mechanisms | 15252124 |
| Sosne et al., Invest Ophthalmol Vis Sci (2010) | Anti-inflammatory effects and wound healing | 20207966 |
For educational and research purposes only. This is not medical advice. TB-500 has no FDA-approved indications and is not intended for human consumption.