Comparison tool
Thymosin Beta-4 vs TB-500 side-by-side
Stack up to four peptides by evidence status, mechanisms, study dosing, side effects, and references.
Comparison tool
Stack up to four peptides by evidence status, mechanisms, study dosing, side effects, and references.
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| Property | Thymosin Beta-4 | TB-500 |
|---|---|---|
| Category | Healing | Healing |
| Also known as | TB-4, Tβ4, Timbetasin | Thymosin Beta-4 fragment (LKKTETQ), Thymosin Beta-4, Fragment |
| FDA approved | No | No |
| Clinical status | The source reports that the Phase 3 dry-eye RGN-259/ARISE-3 study missed its primary endpoints while showing a secondary symptom benefit, and it notes a separate Phase 3 neurotrophic-keratopathy program. It also reports no FDA approval.
| Preclinical - No human clinical trials. FDA Category 2 (pending reclassification to Category 1 per April 15, 2026 HHS announcement; remains Category 2 under current law until formal FDA rule; PCAC review July 23-24, 2026)
|
| What to expect | Wound healing, cardiac repair, tissue regeneration | Muscle recovery, wound healing, injury rehabilitation |
| How it works | Thymosin Beta-4 is described as binding monomeric G-actin, an interaction that can affect actin availability and cytoskeletal turnover. The supplied evidence associates this biology with cell migration, angiogenesis, inflammation-related signaling, and recruitment of endothelial cells, keratinocytes, and progenitor or stem cells at injured sites. It also reports hypotheses involving epicardial activation and cardiac-cell survival under low-oxygen conditions. Mechanistic observations alone do not demonstrate clinical benefit. | TB-500 is presented as a synthetic peptide based on the thymosin beta-4 active region. The supplied source identifies LKKTETQ, residues 17 to 23, as the short sequence commonly reproduced in TB-500 products and ties that region to G-actin binding. Through this actin-related pathway, thymosin beta-4 research connects cytoskeletal remodeling with cell migration into wound areas. The source also reports anti-inflammatory and pro-angiogenic activity in lab models. The main uncertainty is translational: evidence from full-length thymosin beta-4 does not prove that a 7-amino-acid fragment will reproduce the parent molecule's full biological profile. |
| Typical dosing | 2.5-5 mg 2-3x weekly · 2-3x weekly · Subcutaneous injection, topical for eye conditions | 2-2.5 mg twice weekly (loading), then 2.5 mg once weekly (maintenance) · 2x weekly for 4-6 weeks, then 1x weekly |
| Research dosing | 750 mcg - 1.5 mg daily · 4-8 weeks typical protocol · Subcutaneous injection, topical for eye conditions | 2-2.5 mg twice weekly · 4-6 weeks loading, then maintenance · Subcutaneous or intramuscular injection |
| Typical duration | 4-8 weeks typical protocol | 4-6 weeks loading, then maintenance |
| Administration | Subcutaneous injection, topical for eye conditions | Subcutaneous or intramuscular injection |
| Timing | Morning or split doses With or without food | Morning or evening With or without food |
| Evidence level | Clinical Trials | Preclinical |
| Possible side effects |
+5 more
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+7 more
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| Research summary | The supplied source describes randomized, vehicle-controlled ophthalmic studies of RGN-259, a 0.1 % Tbeta4 eye-drop formulation, in dry eye and neurotrophic keratopathy. It reports a 317-patient phase 2/3 dry-eye trial with significant improvements in corneal staining and ocular discomfort, published in peer-reviewed journals. It characterizes cardiac results, including a porcine myocardial-infarction model, as preclinical and reports effects on cell engraftment, infarct size, and recovery; it also says the human cardiac program did not produce an approved drug. Wound-healing and hair-growth findings are described as mainly rodent data. The source does not identify completed pivotal trials establishing systemic benefit outside the eye program, and it reports no controlled human trial data for TB-500 itself. | The supplied research summary places TB-500 mainly in a preclinical evidence category and says most of the stronger evidence concerns full-length thymosin beta-4 rather than the TB-500 fragment. It reports animal findings in wound, scar, tendon, skin, and cardiac injury models. For human data, the source discusses RegeneRx programs using thymosin beta-4 forms: RGN-259 eye drops in a placebo-controlled Phase 3 neurotrophic keratopathy study, where corneal healing was reported in 6 of 10 treated patients versus 1 of 8 on placebo, and RGN-352 injection, which reached Phase 2 in a cardiac program before a manufacturing hold. These programs are not presented as human efficacy trials of the 7-amino-acid TB-500 fragment. For TB-500 as a fragment, the source states there are no completed, published human efficacy trials for muscle or tendon repair and mentions a recently listed cardiovascular biomarker study as early-stage. |
| References | ||
| Full profile | View Details | View Details |
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Track your peptide journeyEducational use only. This information is aggregated from public research and community reports. It is not medical advice, and dosing details are descriptive, not recommendations. Always consult a qualified healthcare professional.