TB-500 (Thymosin Beta-4 Fragment)
TB-500 is a synthetic LKKTETQ fragment marketed for soft-tissue repair, but most human evidence is on full-length topical thymosin beta-4: Sosne 2023 reported corneal healing in 6 of 10 RGN-259 subjects versus 1 of 8 placebo.
TB-500 (Thymosin Beta-4 Fragment) scored 6.3 / 10 (👍 Worth trying) on the BioHarmony scale as a Substance → Peptide.
What It Is
TB-500 is the peptide-market name for a synthetic fragment commonly described as Ac-LKKTETQ, derived from the broader biology of thymosin beta-4. Most published human and animal literature is not on TB-500 itself. It is on full-length Tbeta4, a 43-amino-acid protein involved in actin dynamics, cell migration, angiogenesis, inflammation resolution, and tissue repair.
That distinction matters. The strongest human evidence is ophthalmic full-length Tbeta4, especially RGN-259 eye drops. Sosne 2023 reported complete healing at 4 weeks in 6 of 10 RGN-259-treated neurotrophic keratopathy subjects versus 1 of 8 placebo. Sosne 2015 found no significant difference on dry-eye primary endpoints, but did report several secondary endpoint improvements and no adverse events in a 72-subject Phase II trial. Those studies support the repair biology. They do not directly prove injected TB-500 works for tendons, ligaments, muscle strains, or joint recovery.
In practice, TB-500 is used off-label by peptide users as a recovery peptide, often stacked with BPC-157 in the so-called Wolverine stack. The mechanistic case is real enough to score well: Bock-Marquette 2004 supports cardiac cell migration and survival biology, Malinda 1997 supports endothelial migration, and Wang 2024 adds newer inflammation-resolution support in keratitis models. But the audit found no qualifying recent high-level clinical review or large RCT for TB-500, the TB-500 fragment, or full-length Tbeta4. So the v1.0 rating stays at 7.2 because the repair signal is broad and practical, while the confidence stays limited because the evidence does not match the main consumer use case.
Terminology
- TB-500: Peptide-market name for a synthetic thymosin beta-4 fragment, usually Ac-LKKTETQ.
- Tbeta4 / TB-4: Full-length thymosin beta-4, a 43-amino-acid protein studied in most clinical and preclinical literature.
- LKKTETQ: The actin-binding sequence used to describe the TB-500 fragment.
- G-actin: Globular actin monomer. A building block cells use to remodel their structure and move.
- F-actin: Filamentous actin. The polymerized form of actin that helps shape and move cells.
- RGN-259: RegeneRx ophthalmic full-length Tbeta4 formulation used in dry-eye and neurotrophic keratopathy trials.
- RGN-352: RegeneRx injectable full-length Tbeta4 cardiac-development formulation listed in ClinicalTrials.gov NCT01311518.
- SC: Subcutaneous injection, usually into abdominal or thigh fat.
- IM: Intramuscular injection.
- COA: Certificate of Analysis. A testing document for identity, purity, mass accuracy, sterility, and endotoxin.
- HPLC: High-performance liquid chromatography, a common purity-testing method.
- Endotoxin: Bacterial contamination residue that can cause serious inflammatory reactions if injected.
- WADA: World Anti-Doping Agency. WADA prohibits thymosin-beta4 derivatives including TB-500.
- Neurotrophic keratopathy: A corneal disease caused by impaired corneal nerve function and poor epithelial healing.
- Angiogenesis: New blood-vessel formation. Useful in wound healing, potentially concerning in active cancer.
Dosing & Protocols
Dosing information is summarized from published research and community reports. This is not a prescribing guide. Consult a healthcare provider before starting any protocol.
View 3 routes and 4 protocols
Routes & Forms
| Route | Form | Clinical Range | Community Range |
|---|---|---|---|
| Subcutaneous injection | Lyophilized TB-500 powder reconstituted with bacteriostatic water. | No FDA-approved human dose for musculoskeletal use. | 2-2.5 mg 2x/week loading; 2 mg 1x/week maintenance. |
| Intramuscular injection | Same reconstituted peptide solution, injected into muscle. | No approved clinical range. | Often mirrors subcutaneous dosing. |
| Topical ophthalmic thymosin beta-4 | RGN-259 0.1% full-length thymosin beta-4 eye drops. | 0.1% ophthalmic solution in clinical trials for dry eye and neurotrophic keratopathy. | Clinical-trial setting only. |
Protocols
Acute soft-tissue injury loading Anecdotal
- Dose
- TB-500 2-2.5 mg subcutaneous.
- Frequency
- 2x/week.
- Duration
- 4-6 weeks.
Combine with progressive loading, sleep, protein, and a structured rehab plan. Do not use peptide-driven pain reduction as permission to overload tissue.
Wolverine stack loading Anecdotal
- Dose
- TB-500 2-2.5 mg 2x/week plus BPC-157 250-500 mcg daily.
- Frequency
- Per compound schedule.
- Duration
- 4-6 weeks, then stop or move to maintenance.
Common peptide-community pairing for tendon, ligament, muscle strain, and post-surgical recovery. Mechanisms are complementary, but the stack has no human RCT.
Maintenance after functional improvement Anecdotal
- Dose
- TB-500 2 mg subcutaneous.
- Frequency
- 1x/week.
- Duration
- As needed during high-risk training blocks or chronic irritation.
Use the shortest effective period. If symptoms return after stopping, reassess load management, mechanics, sleep, nutrition, and diagnosis.
Clinical ophthalmic RGN-259 Clinical
- Dose
- 0.1% full-length thymosin beta-4 ophthalmic solution.
- Frequency
- Trial-specific drop schedules.
- Duration
- 28 days in several published ophthalmic studies.
[Sosne 2023](https://pubmed.ncbi.nlm.nih.gov/36613994/) tested topical RGN-259 in neurotrophic keratopathy. It does not validate injected TB-500 for sports injuries.
Use-Case Specific Dosing
| Use Case | Dose | Notes |
|---|---|---|
How this score is calculated →
Upside contribution: 3.30
| Dimension | Weight | Score | Visual | Weighted |
|---|---|---|---|---|
| Efficacy | 25% | 3.2 | 0.800 | |
| Breadth of Benefits | 15% | 4.2 | 0.630 | |
| Evidence Quality | 25% | 2.8 | 0.700 | |
| Speed of Onset | 10% | 3.7 | 0.370 | |
| Durability | 10% | 3.2 | 0.320 | |
| Bioindividuality Upside | 15% | 3.2 | 0.480 | |
| Total | 3.300 |
Upside Rationale
TB-500 (Thymosin Beta-4 Fragment) has real upside when the use case matches its best evidence, especially around recovery repair, injury recovery, wound healing, eye vision. Sosne 2023 and Sosne 2015 support the main positive signal, but the useful part is not the headline mechanism. It is the chance to connect TB-500 (Thymosin Beta-4 Fragment) to a measurable outcome and see whether the expected change appears. The upside is strongest for users with the relevant baseline problem, weaker for optimized users chasing a vague edge, and most honest when paired with tracking. For this report, TB-500 (Thymosin Beta-4 Fragment) earns credit for plausible mechanisms, human or clinical anchors where available, and practical fit. The right read is targeted use, not automatic daily inclusion.
Efficacy (3.2/5.0). TB-500 likely has real repair efficacy, but direct human evidence for injected musculoskeletal use is missing. The best human signal is ophthalmic full-length Tbeta4: Sosne 2023 reported corneal healing in 6 of 10 RGN-259 subjects versus 1 of 8 placebo at 4 weeks, and Dunn 2010 reported healing in chronic neurotrophic corneal defects under compassionate use. Preclinical repair evidence is broad, including Bock-Marquette 2004 for cardiac migration and repair and Xiong 2012 for traumatic brain injury models. The efficacy score stays 3.2 because the biology and community reports are consistent, while the primary consumer use case remains formally unproven.
Breadth of Benefits (4.2/5.0). TB-500 inherits one of the broadest repair maps in the peptide category: corneal epithelium, dermal wounds, cardiac tissue, vascular remodeling, neural repair models, inflammation resolution, and community musculoskeletal recovery. Smart 2007 supports epicardial progenitor mobilization and neovascularization, Morris 2010 supports stroke-model recovery, and Di 2026 reviews kidney-injury mechanisms. Breadth is not the same as proven human usefulness. It means the molecular repair role touches many tissues. That is why the breadth dimension scores higher than the evidence dimension.
Evidence Quality (2.8/5.0). TB-500 has better adjacent evidence than most gray-market peptides but weak evidence alignment for its main use. Human trials and case series exist for full-length topical ophthalmic Tbeta4, including Sosne 2015 and Sosne 2023. Preclinical cardiac, corneal, neurological, and vascular studies are credible. But the audit found no qualifying recent meta-analysis, systematic review, or large RCT for TB-500 or full-length Tbeta4. FDA authority signals are not supportive, and FDA compounding-risk language specifically names the LKKTETQ fragment. Evidence quality stays 2.8 because the literature is real but displaced from injected TB-500 musculoskeletal use.
Speed of Onset (3.7/5.0). TB-500 community timelines are faster than natural recovery for some acute injuries. Acute soft-tissue users commonly report noticeable improvement in 1-2 weeks during loading, while chronic tendinopathy reports cluster around 4-8 weeks. The clinical ophthalmic literature also uses short windows: Sosne 2023 assessed corneal healing at 4 weeks and again after treatment stopped. The short plasma presence of a peptide does not define the full tissue timeline because migration, angiogenesis, and remodeling can continue after exposure. Still, subjective speed is not the same as controlled proof.
Durability (3.2/5.0). TB-500 durability depends on whether real tissue remodeling finishes. If a tendon strain, surgical wound, or epithelial defect heals structurally, some benefit should persist after stopping. If the underlying driver remains, like overload, poor biomechanics, inflammatory disease, or degenerative tissue quality, symptoms can return. The durability score stays above many symptom-masking interventions because the intended effect is repair rather than stimulation. It does not score higher because maintenance dosing is common in the community and long-term human follow-up for injected TB-500 is missing.
Bioindividuality Upside (3.2/5.0). TB-500 appears best suited to acute, well-defined injuries in otherwise capable healers. Younger users, good sleep, high protein intake, adequate collagen cofactors, and progressive loading probably improve outcomes. Poor responders likely include people with unclear diagnoses, active autoimmune drivers, severe degeneration, ongoing overload, poor circulation, or low-quality peptide supply. The full-length versus fragment distinction also adds bioindividuality: a person may respond differently to full-length Tbeta4 than to TB-500. The community signal suggests a meaningful minority notice little, which keeps the score moderate.
Downside contribution: 2.04 (safety risks weighted extra)
| Dimension | Weight | Score | Visual | Weighted |
|---|---|---|---|---|
| Safety Risk | 30% | 2.2 | 0.660 | |
| Side Effect Profile | 15% | 1.1 | 0.165 | |
| Financial Cost | 5% | 2.2 | 0.110 | |
| Time/Effort Burden | 5% | 2.7 | 0.135 | |
| Opportunity Cost | 5% | 1.5 | 0.075 | |
| Dependency / Withdrawal | 15% | 1.0 | 0.150 | |
| Reversibility | 25% | 1.0 | 0.250 | |
| Total | 1.545 | |||
| Harm subtotal × 1.4 | 1.715 | |||
| Opportunity subtotal × 1.0 | 0.320 | |||
| Combined downside | 2.035 | |||
| Baseline offset (constant) | −1.340 | |||
| Effective downside penalty | 0.695 |
Downside Rationale
TB-500 (Thymosin Beta-4 Fragment)'s downside is the gap between plausible benefit and the cost, risk, or uncertainty required to test it. Sosne 2015 and Dunn 2010 frame the caution side better than mechanism talk alone. The main issue may be safety, supervision, legality, product quality, opportunity cost, or simply weak evidence outside the best-matched population. TB-500 (Thymosin Beta-4 Fragment) deserves extra caution when users are pregnant, medically complex, competing under drug rules, taking interacting medications, or trying to replace proven care. The practical orientation is simple: start with the lowest-risk version of the intervention, keep the trial time-bound, and stop when side effects, unclear benefit, or better alternatives show up.
Safety Risk (2.2/5.0). TB-500's main safety concern is potential tumor acceleration in people with active or recent cancer. Tbeta4 supports migration and angiogenesis, which are useful in repair but concerning in cancer contexts. Zhang 2008 links Tbeta4 with pancreatic cancer cell signaling, Gemoll 2015 reports colorectal prognostic associations, and Makowiecka 2019 connects Tbeta4 with melanoma cell migration and invasion. TB-500 does not have a known mutagenic mechanism, but unresolved long-term exposure plus active cancer biology warrants real caution. FDA status and gray-market sourcing add practical risk beyond the molecule.
Side Effect Profile (1.1/5.0). TB-500's reported day-to-day side effects are usually mild: injection-site redness, transient swelling, mild headache, and fatigue during loading. Ophthalmic full-length Tbeta4 trials reported clean short-term tolerability, including no adverse events in Sosne 2015 and no significant adverse effects in Sosne 2023. That does not eliminate long-term or supply-chain risk for injected gray-market TB-500. It does support the low side-effect score for short, properly handled exposures in non-cancer contexts.
Financial Cost (2.2/5.0). TB-500 costs less than regenerative procedures but more than basic recovery supports. Typical gray-market pricing runs roughly $30-60 per 5 mg vial. A 4-6 week loading phase at 2-2.5 mg twice weekly often lands around $60-120 per month. Compounded or medically supervised routes can cost more. The bigger hidden cost is verification: third-party COA, HPLC purity, mass accuracy, sterility, and endotoxin testing matter when something is injected.
Time/Effort Burden (2.7/5.0). TB-500 is not a casual supplement. It requires reconstitution, refrigeration, sterile injection technique, dose tracking, site rotation, and sharps disposal. A twice-weekly loading schedule is manageable, but the friction is high compared with oral supplements, red light therapy, or basic rehab tools. The effort score also reflects the need to pair TB-500 with progressive loading. Peptides cannot replace a sound recovery plan.
Opportunity Cost (1.5/5.0). TB-500 stacks well with other repair tools and usually does not crowd out fundamentals. It can be layered with physical therapy, protein, sleep, collagen plus vitamin C, HRV biofeedback, red light therapy, and BPC-157. The opportunity cost rises when users treat TB-500 as a shortcut and skip diagnosis, progressive loading, imaging when appropriate, or surgical follow-up. The best use case is adjunctive, not replacement therapy.
Dependency/Withdrawal (1.0/5.0). TB-500 has no known withdrawal syndrome, no obvious receptor-dependence pattern, and no classic tolerance loop. Stopping should simply remove the pro-repair signal. If tissue repair completed, the structural benefit may persist. If symptoms return, that usually points to an unresolved driver rather than drug withdrawal. This is one of TB-500's cleaner downside dimensions.
Reversibility (1.0/5.0). TB-500 exposure is highly reversible in the ordinary pharmacology sense: stop dosing and the peptide exposure ends. Injection-site irritation usually resolves, and there is no permanent device, surgery, or receptor-altering dependence. The unresolved exception is cancer-context risk: if a growth or migration signal accelerated an existing tumor, stopping later may not undo that biology. That scenario is why safety risk scores 2.2 while reversibility still scores 1.0 for typical non-cancer use.
Verdict
TB-500 (Thymosin Beta-4 Fragment) is a 6.3/10 fit for people considering recovery repair, injury recovery, wound healing, eye vision, with the strongest case in the populations already represented by the evidence rather than broad wellness use. Sosne 2023 and Sosne 2015 give the report its main anchors, while the score stays worth trying because benefits are context-dependent and the evidence still leaves responder, dose, and long-term questions open. TB-500 (Thymosin Beta-4 Fragment) makes the most sense when the target is concrete, such as a lab marker, symptom pattern, training limitation, or recovery bottleneck. It makes less sense as a background habit taken on faith. In practice, treat TB-500 (Thymosin Beta-4 Fragment) as a tracked experiment: define the outcome first, watch for tradeoffs, and let the response decide whether it earns a place.
✅ Best for: Active adults with acute, well-defined tendon, ligament, muscle, or post-surgical recovery needs who already understand injectable peptide tradeoffs. TB-500 is most rational when conservative recovery is underway but too slow, when BPC-157 alone feels too narrow, and when the user can verify peptide quality. It is also worth tracking for people interested in full-length ophthalmic Tbeta4 research, where human evidence is much stronger than the musculoskeletal TB-500 story. Pair it with progressive loading, protein, sleep, and clinician-aware recovery planning.
❌ Avoid if: You have active cancer, recent cancer, a strong family pattern of aggressive cancers, pregnancy, breastfeeding, or a WADA-tested sport context. Avoid TB-500 if you cannot verify source quality or sterile handling, because gray-market injection risk is separate from the molecule's theoretical profile. Avoid it if you need guideline-grade evidence before acting, because no large human musculoskeletal RCT exists. Also avoid using TB-500 to push through pain while ignoring diagnosis, imaging, surgical instructions, load management, or infection signs.
Use Case Breakdown
The overall BioHarmony score reflects the intervention's primary evidence profile. These subratings are independent assessments per use case.
Recovery / Repair: 7.5/10
Score: 7.5/10TB-500 (Thymosin Beta-4 Fragment) earns 7.5/10 for recovery repair; this is a targeted fit score. Strong preclinical tissue-repair biology and a large community signal support recovery-repair use, but the clinical evidence is mainly full-length topical Tbeta4 in eye disease rather than injected TB-500. Sosne 2023 and Bock-Marquette 2004 support the repair biology without proving tendon or ligament outcomes. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when recovery repair is a real bottleneck and less compelling when basics already cover the same ground.
Injury Recovery: 7.8/10
Score: 7.8/10For injury recovery, TB-500 (Thymosin Beta-4 Fragment) lands at 7.8/10 because context matters. Acute tendon, ligament, and muscle-strain use is the core peptide-community indication, especially in the Wolverine stack with BPC-157. The score stays high because the mechanism and reports are consistent, but there is no human musculoskeletal RCT. Malinda 1997 supports endothelial migration biology, not clinical injury recovery. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when injury recovery is a real bottleneck and less compelling when basics already cover the same ground.
Wound Healing: 7.5/10
Score: 7.5/10TB-500 (Thymosin Beta-4 Fragment) gets 7.5/10 for wound healing; the evidence supports a narrow read. Full-length Tbeta4 has credible wound and corneal-healing evidence: Dunn 2010 reported compassionate-use corneal healing, and Sosne 2023 found 6 of 10 RGN-259 subjects healed versus 1 of 8 placebo. This is stronger for topical ophthalmic use than injected TB-500. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when wound healing is a real bottleneck and less compelling when basics already cover the same ground.
Eye / Vision Health: 7.0/10
Score: 7.0/10TB-500 (Thymosin Beta-4 Fragment) belongs in the 7.0/10 range for eye vision because the signal is conditional. Eye-vision has the best human signal because RGN-259 is full-length topical Tbeta4. Sosne 2015 found secondary endpoint improvements in dry eye, and Sosne 2023 showed a neurotrophic keratopathy healing trend. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when eye vision is a real bottleneck and less compelling when basics already cover the same ground.
Bone / Joint Health: 6.2/10
Score: 6.2/10In bone joint, TB-500 (Thymosin Beta-4 Fragment) earns 6.2/10 only under the right assumptions. Bone-joint use is mostly a community and mechanism extrapolation. Tbeta4 supports cell migration and inflammatory resolution, but no human joint, tendon, or ligament RCT exists for TB-500. Wang 2024 strengthens inflammation-resolution biology in keratitis, not orthopedic efficacy. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when bone joint is a real bottleneck and less compelling when basics already cover the same ground.
Anti-Inflammatory: 6.5/10
Score: 6.5/10The strongest anti inflammatory case puts TB-500 (Thymosin Beta-4 Fragment) at 6.5/10. Anti-inflammatory support is stronger than many other secondary claims. Sosne 2007 reviews corneal anti-inflammatory mechanisms, and Wang 2024 shows pro-resolving pathway activation in keratitis models. Systemic human inflammation outcomes are still unproven. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when anti inflammatory is a real bottleneck and less compelling when basics already cover the same ground.
Cardiovascular: 6.5/10
Score: 6.5/10The cardiovascular score is 6.5/10, and TB-500 (Thymosin Beta-4 Fragment) needs careful framing. Cardiac repair evidence is mostly preclinical. Bock-Marquette 2004 showed improved cardiac function after coronary ligation in mice, while Zhou 2011 found TB4 did not reprogram epicardial cells into cardiomyocytes after myocardial infarction. No successful human cardiovascular efficacy trial exists. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when cardiovascular is a real bottleneck and less compelling when basics already cover the same ground.
Stem Cell Support: 7.0/10
Score: 7.0/10TB-500 (Thymosin Beta-4 Fragment) gets 7.0/10 for stem cell; the evidence supports a narrow read. Stem-cell and progenitor-cell claims have stronger mechanistic support than many TB-500 claims. Smart 2007 described adult epicardial progenitor mobilization and neovascularization, but this was full-length Tbeta4 biology and not a human TB-500 trial. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when stem cell is a real bottleneck and less compelling when basics already cover the same ground.
Healthspan: 6.8/10
Score: 6.8/10For readers prioritizing healthspan, TB-500 (Thymosin Beta-4 Fragment) scores 6.8/10 today. Healthspan support comes from injury recovery, corneal repair, cardiac preclinical work, and neurological models. Di 2026 reviews kidney-repair mechanisms, but it is narrative and translational, not proof of broad human healthspan benefit. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when healthspan is a real bottleneck and less compelling when basics already cover the same ground. The practical test is narrow: define the healthspan marker, run a time-bound trial, and stop if the signal is absent or side effects appear.
Skin / Beauty: 6.5/10
Score: 6.5/10The 6.5/10 skin beauty score reflects evidence plus practical constraints. Skin-beauty is a secondary extrapolation from wound healing, angiogenesis, matrix remodeling, and anti-inflammatory pathways. Philp 2004 reported wound-healing and hair-follicle development effects in animal work, but no human cosmetic RCT supports TB-500. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when skin beauty is a real bottleneck and less compelling when basics already cover the same ground. The practical test is narrow: define the skin beauty marker, run a time-bound trial, and stop if the signal is absent or side effects appear.
Traumatic Brain Injury: 6.5/10
Score: 6.5/10TB-500 (Thymosin Beta-4 Fragment) rates 6.5/10 for tbi; outcomes matter more than mechanism. TBI scoring is based on animal evidence, especially Xiong 2012 showing neuroprotective and neurorestorative effects after experimental traumatic brain injury. This is promising preclinical biology, not a human TBI treatment recommendation. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when tbi is a real bottleneck and less compelling when basics already cover the same ground. The practical test is narrow: define the tbi marker, run a time-bound trial, and stop if the signal is absent or side effects appear.
Chronic Pain Management: 6.2/10
Score: 6.2/10TB-500 (Thymosin Beta-4 Fragment) fits chronic pain at 6.2/10 when the baseline problem is real. Chronic-pain benefit is indirect through tissue recovery and inflammation modulation. Chronic tendinopathy reports are common, but no human pain RCT exists for TB-500. Use the score as an injury-resolution signal rather than analgesic evidence. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when chronic pain is a real bottleneck and less compelling when basics already cover the same ground. The practical test is narrow: define the chronic pain marker, run a time-bound trial, and stop if the signal is absent or side effects appear.
Nerve Regeneration: 6.0/10
Score: 6.0/10TB-500 (Thymosin Beta-4 Fragment) fits nerve regeneration at 6.0/10 when the baseline problem is real. Nerve-regeneration support comes from stroke and brain-injury remodeling models rather than human peripheral-nerve trials. Morris 2010 supports axonal and neurological recovery signals in rats, while human evidence remains absent for injected TB-500. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when nerve regeneration is a real bottleneck and less compelling when basics already cover the same ground.
Longevity / Lifespan: 6.0/10
Score: 6.0/10The longevity score is 6.0/10, and TB-500 (Thymosin Beta-4 Fragment) needs careful framing. Longevity is speculative. Tissue repair, inflammation resolution, and injury resilience plausibly support healthspan, but no lifespan or age-related disease trial exists. The score remains moderate because chronic peptide use adds unresolved safety and cancer-context uncertainty. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when longevity is a real bottleneck and less compelling when basics already cover the same ground. The practical test is narrow: define the longevity marker, run a time-bound trial, and stop if the signal is absent or side effects appear.
Neuroprotection: 5.8/10
Score: 5.8/10For readers prioritizing neuroprotection, TB-500 (Thymosin Beta-4 Fragment) scores 5.8/10 today. Animal stroke and traumatic brain injury models support a neurorestorative signal, including Morris 2010 and Xiong 2012. The score remains moderate because these are preclinical models and do not establish human TBI or stroke benefit. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when neuroprotection is a real bottleneck and less compelling when basics already cover the same ground.
Hair / Nail Health: 5.5/10
Score: 5.5/10Hair Nail is a 5.5/10 use case for TB-500 (Thymosin Beta-4 Fragment), not a blanket claim. Hair-follicle support rests mainly on animal and mechanistic evidence. Philp 2004 title-matches thymosin beta-4 effects on hair-follicle development, but the audit flagged the old PMID as unrelated, so no PubMed identifier is used here. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when hair nail is a real bottleneck and less compelling when basics already cover the same ground.
Strength / Power: 5.5/10
Score: 5.5/10TB-500 (Thymosin Beta-4 Fragment) earns 5.5/10 for strength power; this is a targeted fit score. Strength-power benefits are indirect: faster injury recovery may preserve training continuity. There is no direct strength, hypertrophy, or power RCT for TB-500. This score reflects rehabilitation continuity, not acute performance enhancement. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when strength power is a real bottleneck and less compelling when basics already cover the same ground. The practical test is narrow: define the strength power marker, run a time-bound trial, and stop if the signal is absent or side effects appear.
Acute Pain Relief: 5.5/10
Score: 5.5/10The 5.5/10 acute pain score reflects evidence plus practical constraints. Acute-pain effects are likely secondary to faster tissue recovery, lower inflammation, or increased confidence during rehab. There is no direct acute-pain study for TB-500. The score remains below the injury-recovery score for that reason. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when acute pain is a real bottleneck and less compelling when basics already cover the same ground. The practical test is narrow: define the acute pain marker, run a time-bound trial, and stop if the signal is absent or side effects appear.
Immune Function: 5.5/10
Score: 5.5/10Immune Function is a 5.5/10 use case for TB-500 (Thymosin Beta-4 Fragment), not a blanket claim. Thymosin-family compounds have immune relevance, but TB-500 is not thymosin alpha-1 and should not be treated as a primary immune protocol. Wang 2024 supports host-defense modulation in keratitis models only. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when immune function is a real bottleneck and less compelling when basics already cover the same ground.
Endurance / Cardio: 5.2/10
Score: 5.2/10For endurance cardio, TB-500 (Thymosin Beta-4 Fragment) lands at 5.2/10 because context matters. Endurance-cardio support is indirect. Tbeta4 cardiac and vascular preclinical studies such as Bock-Marquette 2004 and Smart 2007 do not translate into proven endurance performance in humans. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when endurance cardio is a real bottleneck and less compelling when basics already cover the same ground. The practical test is narrow: define the endurance cardio marker, run a time-bound trial, and stop if the signal is absent or side effects appear.
Hormonal / Endocrine: 5.0/10
Score: 5.0/10TB-500 (Thymosin Beta-4 Fragment) belongs in the 5.0/10 range for hormonal because the signal is conditional. TB-500 is not an endocrine lever. No hormonal disruption signal is obvious in the clinical-trial literature, but there is also no meaningful testosterone, thyroid, fertility, or adrenal outcome evidence. Score stays neutral. That makes TB-500 (Thymosin Beta-4 Fragment) more defensible when hormonal is a real bottleneck and less compelling when basics already cover the same ground. The practical test is narrow: define the hormonal marker, run a time-bound trial, and stop if the signal is absent or side effects appear.
Frequently Asked Questions
What does TB-500 actually do?
TB-500 is usually the synthetic LKKTETQ fragment marketed from thymosin beta-4 biology, with claimed effects on actin dynamics, cell migration, angiogenesis, and inflammation resolution. Bock-Marquette 2004 supports full-length Tbeta4 repair biology in cardiac models, while Sosne 2023 supports topical full-length ophthalmic Tbeta4. Neither proves injected TB-500 heals tendons in humans.
How do you dose TB-500 for injury recovery?
Community dosing is 2-2.5 mg subcutaneous twice weekly for 4-6 weeks, then 2 mg weekly if maintenance is used. That protocol is anecdotal, not FDA-approved, and not validated in a musculoskeletal RCT. The clinical ophthalmic work uses 0.1% full-length Tbeta4 drops, which is a different route, molecule context, and risk profile.
Is TB-500 safe, and what about cancer risk?
TB-500's biggest safety question is tumor acceleration in people with active or recent cancer, not direct DNA damage. Tbeta4 expression and pathways have been linked with pancreatic and colorectal cancer biology in Zhang 2008 and Gemoll 2015. Human TB-500 long-term safety data are not strong enough to dismiss that concern.
TB-500 vs BPC-157: which one should I use?
TB-500 and BPC-157 are usually treated as complementary, not interchangeable. BPC-157 is more tendon, gut, and nitric-oxide-pathway oriented in community use; TB-500 is framed as broader actin-migration and remodeling support. The Wolverine stack combines both, but the stack itself has no human RCT. Use rehab fundamentals first, then weigh peptide risk.
Is TB-500 the same as full-length thymosin beta-4?
No. TB-500 is usually the LKKTETQ fragment, while full-length thymosin beta-4 is a 43-amino-acid protein with additional functional regions. Most human studies use full-length Tbeta4, especially topical RGN-259 eye drops. The audit specifically flagged this distinction because extrapolating full-length Tbeta4 evidence to injected TB-500 is a major evidence gap.
Who should avoid TB-500?
Avoid TB-500 with active cancer, recent cancer, strong aggressive-cancer family history, pregnancy, breastfeeding, WADA-tested sport, or inability to verify source quality. FDA has flagged TB-500 in peptide-compounding safety-risk contexts, and WADA prohibits thymosin-beta4 derivatives. Cancer caution matters because Tbeta4 pathways overlap with migration and angiogenesis.
How fast will I see results from TB-500?
Acute soft-tissue users often report changes within 1-2 weeks, while chronic tendinopathy reports usually need 4-8 weeks. That timeline is community experience, not trial evidence. The clinical eye literature used 28-day courses, with Sosne 2023 reporting corneal-healing differences at 4 weeks and follow-up durability at day 43.
Is TB-500 legal or banned in sport?
TB-500 is not FDA-approved for human use and is banned in tested sport. WADA names thymosin-beta4 and derivatives including TB-500 as prohibited at all times. FDA also lists the TB-500 fragment in a compounding safety-risk context and has issued warning-letter language for unapproved thymosin beta-4 products.
How This Score Could Change
BioHarmony scores are living assessments. New research, regulatory changes, or personal context can shift the score up or down. These are the most likely scenarios that would change this intervention's rating.
| Scenario | Dimensions changed | New score |
|---|---|---|
| Human musculoskeletal RCT confirms clinically meaningful tendon or ligament recovery | Efficacy 3.2 to 4.0; Evidence 2.8 to 3.8 | 7.4 / 10 💪 Strong recommend |
| Long-term safety study follows 500+ peptide users for 2+ years with no cancer signal | Safety 2.2 to 1.5 | 7.0 / 10 💪 Strong recommend |
| Human case report or pharmacovigilance cluster links TB-500 to tumor acceleration | Safety 2.2 to 3.5 | 5.9 / 10 👍 Worth trying |
| FDA approves a thymosin beta-4 product for a repair indication and supply chain normalizes | Evidence 2.8 to 3.5; Safety 2.2 to 1.8 | 7.2 / 10 💪 Strong recommend |
| Large peptide-user epidemiology study shows a cancer or severe-infection signal | Safety 2.2 to 4.0; Side effects 1.1 to 2.0 | 5.4 / 10 👍 Worth trying |
| Human cardiac trial confirms clinically meaningful infarct or function improvement | Efficacy 3.2 to 3.7; Evidence 2.8 to 3.3; Breadth 4.2 to 4.5 | 7.1 / 10 💪 Strong recommend |
Key Evidence Sources
- Sosne G et al. 2023 - 0.1% RGN-259 ophthalmic solution in neurotrophic keratopathy Phase III trial, International Journal of Molecular Sciences. Full-length topical Tbeta4, not TB-500; complete healing at 4 weeks in 6 of 10 RGN-259 subjects versus 1 of 8 placebo.
- Sosne G, Ousler GW 2015 - Thymosin beta-4 ophthalmic solution for dry eye Phase II trial, Clinical Ophthalmology. 72-subject randomized dry-eye trial; primary endpoints not significant, secondary endpoints improved, no adverse events reported.
- Dunn SP et al. 2010 - Treatment of chronic nonhealing neurotrophic corneal epithelial defects with thymosin beta-4, Annals of the New York Academy of Sciences. Nine compassionate-use patients; geographic defects showed healing signal. Corrects the v0.x mismatched Dunn identifier.
- Dunn SP et al. 2010 - Treatment of chronic nonhealing neurotrophic corneal epithelial defects with thymosin beta-4, Archives of Ophthalmology. Four-patient case series under FDA investigational new drug compassionate use protocol.
- Bock-Marquette I et al. 2004 - Thymosin beta-4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair, Nature. Mouse cardiac repair and cell-migration study; correct PMID replacing the old mismatched identifier.
- Smart N et al. 2007 - Thymosin beta-4 induces adult epicardial progenitor mobilization and neovascularization, Nature. Preclinical adult epicardial progenitor and neovascularization paper; DOI used because audit did not verify a PMID.
- Riley PR, Smart N 2009 - Thymosin beta-4 induces epicardium-derived neovascularization in the adult heart, Biochemical Society Transactions. Review/summary of cardiac neovascularization biology.
- Srivastava D et al. 2007 - Thymosin beta-4 is cardioprotective after myocardial infarction, Annals of the New York Academy of Sciences. Preclinical cardioprotection review and mechanistic summary.
- Zhou B et al. 2011 - Thymosin beta-4 treatment after myocardial infarction does not reprogram epicardial cells into cardiomyocytes, Journal of Molecular and Cellular Cardiology. Important negative or limiting cardiac-fate paper.
- Malinda KM et al. 1997 - Thymosin beta-4 stimulates directional migration of human umbilical vein endothelial cells, FASEB Journal. Foundational endothelial migration and angiogenesis mechanism.
- Sosne G et al. 2001 - Thymosin beta-4 promotes corneal wound healing and modulates inflammatory mediators in vivo, Experimental Eye Research. Early in vivo corneal wound-healing and inflammatory mediator study.
- Sosne G et al. 2002 - Thymosin beta-4 promotes corneal wound healing and decreases inflammation in vivo following alkali injury, Experimental Eye Research. Mouse alkali-injury corneal model; accelerated re-epithelialization and lower inflammatory markers.
- Sosne G et al. 2007 - Thymosin beta-4: a novel corneal wound healing and anti-inflammatory agent, Clinical Ophthalmology. Ophthalmic review of corneal wound healing, apoptosis, migration, and inflammation effects.
- Philp D et al. 2004 - Thymosin beta-4 promotes angiogenesis, wound healing, and hair follicle development, Mechanisms of Ageing and Development. Title-confirmed institutional repository page; no PMID emitted because audit found the v0.x PMID unrelated.
- Morris DC et al. 2010 - Thymosin beta-4 improves functional neurological outcome in a rat model of embolic stroke, Neuroscience. Preclinical stroke model; neurological recovery signal.
- Xiong Y et al. 2012 - Neuroprotective and neurorestorative effects of thymosin beta-4 after traumatic brain injury in rats, Journal of Neurosurgery. Preclinical traumatic brain injury model.
- Wang Y et al. 2024 - Activation of pro-resolving pathways mediates thymosin beta-4 effects during Pseudomonas aeruginosa-induced keratitis, Frontiers in Immunology. 2024 mechanistic animal and in-vitro keratitis study from audit Track 1 near misses; not a large human RCT.
- Di H et al. 2026 - Thymosin beta-4: an emerging therapeutic candidate for kidney diseases, Peptides. 2026 narrative review from audit Track 1 near misses; excluded from qualifying modern evidence because it is not systematic.
- Zhang Y et al. 2008 - Thymosin beta-4 is overexpressed in human pancreatic cancer cells and stimulates cytokine secretion and JNK activation, Cancer Biology and Therapy. Cancer-context safety concern source.
- Gemoll T et al. 2015 - MALDI-imaging reveals thymosin beta-4 as an independent prognostic marker for colorectal cancer, Oncotarget. Cancer-context safety concern source.
- Makowiecka A et al. 2019 - Thymosin beta-4 regulates focal adhesion formation in human melanoma cells and affects migration and invasion, Frontiers in Cell and Developmental Biology. Melanoma cell migration and invasion mechanism relevant to caution language.
- ClinicalTrials.gov NCT01311518 - RGN-352 injectable thymosin beta-4 for acute myocardial infarction. RegeneRx Phase 2 cardiac trial record; no results posted and actual enrollment listed as 0.
- FDA 2026 - Genogenix warning letter. FDA warning-letter language for unapproved thymosin beta-4 products.
- FDA - Certain bulk drug substances for use in compounding may present significant safety risks. FDA safety-risk context naming thymosin beta-4 fragment LKKTETQ, also known as TB-500.
- WADA - What is prohibited. WADA prohibits thymosin-beta4 and derivatives including TB-500 at all times.
Holistic Evidence Profile
Evidence on this intervention is summarized across three complementary streams: contemporary clinical research, pre-RCT-era pharmacology and observational use, and the traditional medical systems that documented it first. Convergence across streams signals higher confidence; divergence is surfaced honestly.
Modern Clinical Research
Confidence: Limited
Citations: Sosne 2023, Sosne 2015, Dunn 2010, Wang 2024, Di 2026, FDA 2026, WADA 2026
Pre-RCT-Era Pharmacology and Use
Confidence: Emerging
Citations: Malinda 1997, Bock-Marquette 2004, Smart 2007, RegeneRx Clinical Program 2010, ClinicalTrials.gov 2011
Traditional Medicine Systems
Confidence: Low
Citations: Di 2026
Holistic Evidence for TB-500 (Thymosin Beta-4 Fragment)
The lenses do not fully converge. Modern science supports Tbeta4 as a tissue-repair and inflammation-resolution molecule, especially in corneal models and small ophthalmic human trials. Historical development supports why the compound became attractive for regenerative medicine. Traditional evidence contributes almost nothing specific. Honest synthesis: TB-500 has a strong repair story and a strong community signal, but the published human evidence mostly belongs to full-length topical thymosin beta-4, not injected TB-500 for musculoskeletal recovery.
What to Track If You Try This
These are the data points that matter most while running a 30-day Experiment with this intervention.
How to read this section
- Pre
- Test or score before starting the protocol. Anchors a baseline.
- During
- Track while running the protocol so you can see if anything is changing.
- Post
- Re-test after a full cycle to confirm the change held.
- Up
- The marker should rise. For most positive outcomes, that is a good sign.
- Down
- The marker should fall. For most positive outcomes, that is a good sign.
- Stable
- The marker should hold steady. Big swings in either direction are a yellow flag.
- Watch
- Direction depends on dose, timing, and your baseline. Pay close attention to the trend.
- N/A
- No expected direction. The entry is there to anchor a baseline reading.
- Primary
- The Pulse dimension most likely to shift. Track this first.
- Secondary
- Also relevant, but a smaller or less consistent shift. Track if Primary is unclear.
Bloodwork to Order
Open These Markers In Your Dashboard
- hs-CRP Baseline (pre-protocol) During | Expected Down
- WBC During | Expected Stable
Pulse Dimensions to Watch
- Body During | Expected Up | Primary
- Energy During | Expected Up | Secondary
- Calm During | Expected Stable | Tertiary
Subjective Signals (Daily Voice Card)
- Injury Pain Scale 1-5 | During | Expected Down
- Range Of Motion Scale 1-5 | During | Expected Up
- Injection-Site Irritation Scale 1-5 | During | Expected Watch
Red Flags: Stop and Consult
- Injection-site infection
- Rapidly worsening swelling or pain
Other interventions for Recovery & Repair
See all ratings →📊 How BioHarmony scoring works
BioHarmony translates a weighted expected-value calculation into a reader-facing 0–10 score. Tier bands: Skip 0–3.6, Caution 3.7–4.7, Neutral 4.8–5.7, Worth Trying 5.8–6.9, Strong Recommend 7.0–7.9, Top-tier 8.0+.
Harm-type downsides (safety risk, side effects, reversibility, dependency) carry a 1.4× precautionary multiplier. Harm weighs more than benefit. Opportunity-type downsides (financial cost, time/effort, opportunity cost) are subtracted at face value.
Use case subratings are independent assessments of how well the intervention addresses specific health goals. They are not components of the overall score. Each subrating reflects the scorer's judgment based on use-case-specific evidence, safety, and effect sizes.
Every dimension is evaluated on a 1–5 scale, and the baseline (1) is subtracted before weighting. A perfect intervention with zero downsides contributes zero penalty rather than a residual floor, so top-tier scores are actually reachable.
EV = Upside − Downside
EV = 2.300 − 0.695 = 1.605
Formula v0.5 maps EV = 0 to score 5.0. Above neutral, 1 EV point equals 1 score point. Below neutral, 1 EV point equals about 0.71 score points, so EV = −7 reaches 0.0 while EV = +5 reaches 10.0. Both sides use the full 5-point half-scale.
Score = 5 + (1.605 / 5) × 5 = 6.6 / 10
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