Thymosin beta-4: research

A peptide studied for eye conditions and skin wounds; tendon-repair injections lack controlled human evidence.

Also called: Tβ4, TB4, TB-4, Timbetasin, Timbetasin acetate, RGN-259, RGN-137, RGN-352, NL005, a recombinant Tβ4-related product.

Healing and repair peptides · Full-length actin-binding peptide; related recombinant trial formulations.

Large dry-eye trials and ulcer results combining gel strengths showed no clear benefit. No controlled human trial supports routine tendon-repair injections.

Studies

• Synthetic Tβ4: IV dose finding. rct, n=40, Single-dose phase: 40 healthy volunteers in four cohorts of 10; repeated-dose enrollment overlap is not clear in the abstract.. Short-term IV tolerability does not establish a subcutaneous recovery dose. (source)
• NL005: single IV doses. rct, n=54, Healthy Chinese adults; recombinant 44-residue NL005.. Early IV safety and PK only; not an efficacy or subcutaneous-dose trial. (source)
• NL005: 10 daily IV doses. rct, n=30, Healthy Chinese adults; recombinant 44-residue NL005.. Early IV safety and PK only; not an efficacy or subcutaneous-dose trial. (source)
• Corneal defects: four compassionate-use cases. case-series, n=4, Four adults with chronic neurotrophic corneal defects.. Uncontrolled corneal observations; likely overlap with the nine-case report. (source)
• Corneal defects: nine compassionate-use cases. case-series, n=9, Nine adults aged 37–84 with chronic neurotrophic corneal defects.. Small uncontrolled series with improvement in some corneal defects. (source)
• Severe dry eye: six doses daily. rct, n=9, Nine adults with severe dry eye, including graft-versus-host disease.. Promising but extremely small; eyes are not independent participants. (source)
• Dry eye: twice-daily drops. rct, n=72, 72 adults with moderate to severe dry eye.. Primary endpoints failed; positive secondary results were exploratory. (source)
• ARISE-1: high and low eye-drop strengths. rct, n=317, 317 enrolled dry-eye participants.. Completed phase 2/3 registry; no numerical results posted. (source)
• ARISE-2: four doses daily. rct, n=601, Adults with dry eye.. Registry primary results show little separation from vehicle. (source)
• ARISE-3: 14 days of eye drops. rct, n=700, Adults with dry eye.. Registry primary results show little separation from vehicle. (source)
• Corneal wounds after diabetic eye surgery. rct, n=12, 12 diabetic patients undergoing vitrectomy.. Both groups healed; the trial stopped early for slow recruitment. (source)
• SEER-1: neurotrophic corneal defects. rct, n=18, 18 adults with stage 2 or 3 neurotrophic keratopathy.. The small trial missed its primary statistical endpoint; a later secondary outcome favored RGN-259. (source)
• Pressure ulcers: three gel strengths. rct, n=72, 72 adults with pressure ulcers.. Pooled active gel did not yield a higher wound-closure proportion than placebo. (source)
• Venous ulcers: three gel strengths. rct, n=73, Venous leg ulcers; paper reports 73 randomized, registry results include 72.. The pooled closure result did not favor active gel; claims about faster healing concern selected healers. (source)
• Fragile-skin wounds: early gel trial. rct, n=30, 30 participants with epidermolysis bullosa; adults and children were eligible.. Pooled closure did not favor active gel; recruitment and drug expiry ended the trial. (source)
• CELEB: later fragile-skin gel trial. rct, n=4, Four participants enrolled with junctional or dystrophic epidermolysis bullosa.. Terminated after four participants for a business decision; no posted results. (source)
• Scalp dermatitis: gel every other day. rct, n=71, 71 patients with scalp seborrheic dermatitis; 21 additional healthy controls.. A small randomized scalp study reported benefit; it does not establish injected hair regrowth. (source)
• Hair-regrowth growth-factor mixture. single-arm, n=1000, 1,000 patients with hair loss.. An uncontrolled mixture cannot show that Tβ4 grows hair. (source)
• Heart attack: pretreated cell transplant. rct, n=10, Ten adults with STEMI.. Cell pretreatment is not evidence for giving a person a Tβ4 injection. (source)
• Knee pain: BPC-157 with Tβ4. case-series, n=17, 17 charts reviewed; 16 patients reached, including four given Tβ4.. Four combination cases cannot establish Tβ4 benefit or added value. (source)
• Heart attack: published 96-patient trial. rct, n=96, 96 adults with STEMI after PCI.. Overall cardiac result was negative; subgroup findings need confirmation. (source)
• NL005 cardiac registry: phase 2a. rct, n=62, Adults with STEMI after PCI.. Registry marked completed; no results posted. (source)
• NL005 cardiac registry: phase 2b. rct, n=90, Adults with STEMI after PCI.. Registry marked completed; no results posted. (source)
• SEER-2: no posted results. rct, Registered future or ongoing program; actual enrolled count is not published.. No outcomes available as of review; planned regimens are not trial-proven doses. (source)
• NL005 phase 2c: planned trial. rct, Registered future or ongoing program; actual enrolled count is not published.. No outcomes available as of review; planned regimens are not trial-proven doses. (source)
• Cochrane: neurotrophic corneal therapies. systematic-review, n=494, Seven RCTs of several therapies, 494 participants; one RGN-259 study had 18.. Cochrane judged the RGN-259 evidence uncertain and imprecise. (source)
• Tβ4 in impaired-healing mouse models. animal, Diabetic and aged mice.. Preclinical repair effects cannot establish community injection dosing. (source)
• Skin safety: 15 healthy volunteers. rct, n=15, 15 healthy volunteers in three sequential cohorts.. Early skin safety was described in reviews; the primary trial report was not located. (source)

Gaps: Community subcutaneous repair doses lack controlled human efficacy and dose-finding trials. Long-term cancer, reproductive, immune and repeated-cycle safety remain unknown. ARISE-1 and CELEB have no public numerical results; some other results exist only in registries. The 96-patient cardiac paper was abstract-access only; dose, arm effect sizes and event rates could not be confirmed. One NL005 cardiac registry says 1.0 mcg/kg in its arm and 1.5 mcg/kg in its intervention field. No dose protocol was made from it. Possible report overlap limits exact human-study counts; there is no justified pooled patient total. No validated home-mixed shelf life or oral dose was found. Knee, scalp intradermal and dental submucosal routes cannot be represented by the current protocol route enum. A 15-volunteer skin safety study was recoverable only through reviews; frequency and detailed safety counts remain incomplete. A pediatric congenital-heart-surgery paper was a proposal, not completed trial evidence.

Related to Thymosin beta-4

• BPC-157: An experimental repair peptide with mostly animal evidence and a few small human reports.
• TB-500: A short piece of thymosin beta-4 with no proven repair benefit in humans.
• GHK-Cu: A copper-binding skin peptide with small topical studies and untested systemic injections.
• AHK-Cu: A copper peptide used in scalp serums, with laboratory findings and weak patent-only human data.
• ARA-290: Experimental peptide studied for small-fiber nerve damage, with uncertain pain relief and safety.
• Ac-SDKP: An experimental repair peptide with old human studies, but no proven healing dose.

Thymosin beta-4: the short version

Sources

• 503B Bulk Drug Substances List, FDA · FDA · 2026
• Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act, FDA · FDA · 2026
• Cellulitis, NHS · NHS · 2026
• July 23-24, 2026, Meeting of the Pharmacy Compounding Advisory Committee – FDA Briefing Document for TB-500-Related Bulk Drug Substances (TB-500 (free base) and TB-500 acetate), FDA · FDA · 2026
• Medicines, European Medicines Agency · European Medicines Agency · 2026
• MHRA Products | Home, MHRA · MHRA · 2026
• The 2026 Prohibited List, World Anti-Doping Agency · WADA · 2026
• Therapeutic Goods (Poisons Standard—October 2026) Instrument 2026, Australian Government · Australian Government · 2026
• Think twice before injecting peptides bought online: unauthorized products can seriously harm you, Health Canada · Health Canada · 2026
• Thymosin Beta-4, Sport Integrity Australia · 2026
• Anaphylaxis, NHS · NHS · 2023
• Using intramuscular injections in people on oral anticoagulants, NHS Specialist Pharmacy Service · NHS Specialist Pharmacy Service · 2023
• Medical and surgical interventions for neurotrophic keratopathy., Kruoch Z et al. · The Cochrane database of systematic reviews · 2025
• Recombinant human thymosin beta 4 improves ischemic cardiac dysfunction in mice and patients with acute ST-segment elevation myocardial infarction after reperfusion., Zhang Y et al. · Cardiovascular research · 2025
• 0.1% RGN-259 (Thymosin ß4) Ophthalmic Solution Promotes Healing and Improves Comfort in Neurotrophic Keratopathy Patients in a Randomized, Placebo-Controlled, Double-Masked Phase III Clinical Trial., Sosne G et al. · International journal of molecular sciences · 2022

Sources checked: 2026-10-18.

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