TB-500 / thymosin beta-4-related products

ID: tb500

Aliases: Ac-LKKTETQ, LKKTETQ, Tbeta4, Thymosin beta-4 fragment, RGN-259-related evidence, TB500

Type: compound

Route/form: stronger human Tbeta4 studies are topical/ophthalmic/wound contexts; injected TB-500 fragment use is not clinically established

Status: research

Evidence level: human RCT

Best data tier: human controlled/review; exact-use indirect

Support scope: human, non-human/mechanistic, review/regulatory

Source types: early_human, human_physiology, human_rct, human_trial, medicinal_chemistry, preclinical, review

Linked sources: 12

Broad outcomes: Muscle growth / performance / recovery, Skin / wound repair

Reading note: These are curation notes anchored to linked sources, not a clinical recommendation or protocol.

Targets / mechanism

• actin binding
• cell migration
• angiogenesis
• wound repair pathways
• inflammatory mediator modulation

Optimization domains

• injury
• wound healing
• dry eye
• soft tissue repair

Research basis

• Direct TB-500 analytical literature identifies Ac-LKKTETQ as an N-acetylated active-region fragment related to thymosin beta-4, so the fragment/full-length distinction needs to stay visible.
• The strongest bridge for TB-500-style claims is the LKKTETQ/Tbeta4 repair literature: animal dermal and ligament models, actin/cell-migration biology, angiogenesis, and full-length thymosin beta-4 wound/eye/corneal human contexts.
• Human anchors exist mostly for full-length thymosin beta-4/RGN-259 in topical, ophthalmic, neurotrophic corneal, venous-ulcer, and wound-fluid contexts, not for injected gray-market TB-500 fragment use.

Limits, risks, and missing evidence

• Injected TB-500 fragment use for tendon, muscle, or recovery is not directly proven by the full-length topical/ophthalmic human literature.
• TB-500, thymosin beta-4, LKKTETQ, and RGN-259 should be treated as related but not interchangeable molecules/formulations.
• The evidence supports repair biology plausibility more than a validated human soft-tissue protocol.

Risk flags

• fragment vs full length mismatch
• route translation uncertain
• preclinical bridge
• limited direct human fragment data
• unapproved context

Linked papers, labels, and reviews

1. Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500
   medicinal_chemistry / pubmed_tb500_fragment_characterization_2012
   Direct TB-500 chemistry source: identifies Ac-LKKTETQ, the N-acetylated 17-23 fragment of human thymosin beta-4; not an efficacy study.
2. Thymosin beta 4 and a synthetic peptide containing its actin-binding domain promote dermal wound repair in db/db diabetic mice and in aged mice
   preclinical / pubmed_tb4_dermal_repair_2003
   Important bridge source: full-length Tbeta4 and the LKKTETQ actin-binding peptide promoted dermal wound repair in animal models.
3. Thymosin beta4 accelerates wound healing
   preclinical / pubmed_tb4_wound_healing_1999
   Early animal wound-healing source for full-length Tbeta4 repair biology.
4. Thymosin beta-4 enhances the healing of medial collateral ligament injury in rat
   preclinical / pubmed_tb4_ligament_rat_2013
   Rat ligament-injury source; relevant to soft-tissue repair claims, but not direct human TB-500 evidence.
5. Thymosin beta 4 ophthalmic solution for dry eye: randomized phase II trial
   human_rct / pmc_tb4_dry_eye_2015
   Full-length thymosin beta-4 topical/ophthalmic, not necessarily injected TB-500 fragment.
6. The effect of thymosin beta 4 treatment of venous ulcers
   human_trial / pubmed_tb4_ulcers_2010
   Human wound-healing context for full-length Tbeta4.
7. Treatment of chronic nonhealing neurotrophic corneal epithelial defects with thymosin beta4
   early_human / pubmed_tb4_neurotrophic_corneal_defects_2010
   Uncontrolled human topical eye-drop case series for full-length Tbeta4 in chronic corneal epithelial defects.
8. Determination of thymosin beta4 and protein in human wound fluid after abdominal surgery
   human_physiology / pubmed_tb4_human_wound_fluid_2007
   Human physiology source showing endogenous Tbeta4 in wound fluid after surgery; supports biological plausibility, not treatment efficacy.
9. Thymosin beta 4 promotes corneal wound healing and modulates inflammatory mediators in vivo
   preclinical / pubmed_tb4_corneal_wound_2001
   Rat corneal wound model; supports topical Tbeta4 repair and inflammatory-modulation biology.
10. Thymosin-beta4 modulates corneal matrix metalloproteinase levels and polymorphonuclear cell infiltration after alkali injury
    preclinical / pubmed_tb4_alkali_injury_2005
    Mouse corneal alkali-injury model; supports MMP/TIMP and neutrophil-infiltration mechanisms in local injury repair.
11. Thymosin beta4: actin-sequestering protein moonlights to repair injured tissues
    review / pubmed_tb4_repair_review_2005
    Mechanism review for actin sequestration, dermal/corneal wound healing, and broader injury-repair hypotheses; not direct TB-500 clinical evidence.
12. Thymosin beta4 and cardiac repair
    review / pubmed_tb4_cardiac_repair_2010
    Related Tbeta4 cardiac-repair biology; included as indirect repair-mechanism context, not as evidence for injectable TB-500 musculoskeletal use.