Side-by-side · Research reference

TB-500vsVIP

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

APhase 2HUMAN-REVIEWED8/46 cited

BPhase 3HUMAN-REVIEWED9/42 cited

TB-500

Thymosin β4 fragment · Healing

2 mgPer doseGoldstein 2012

Phase 2Evidence levelGoldstein 2012

~2 hrHalf-life

SQ or IM · Multiple sites · 2–3×/week

VIP

Neuropeptide · VPAC1/VPAC2 Agonist · Emergency Use Authorization (COVID-19 ARDS)

IntravenousPrimary routeBrown 2023

ARDSLead indicationUdupa 2025

Phase 3Development stage

IV infusion · Inhaled (investigational)Brown 2023 Boesing 2022

01Mechanism of Action

Parameter

TB-500

VIP

Primary target

G-actin (sequestering) + cell-surface integrinsGoldstein 2012

VPAC1 and VPAC2 G-protein-coupled receptorsUdupa 2025

Pathway

Actin remodelling → cell migration; integrin-linked signaling → angiogenesis; anti-inflammatory cytokine modulationGoldstein 2012 Malinda 1999

VIP → VPAC1/VPAC2 activation → cAMP elevation → Pulmonary vasodilation + epithelial protection

Downstream effect

Accelerated wound healing, endothelial migration, hair follicle regeneration, cardiac repair (preclinical)Goldstein 2012

Anti-inflammatory cytokine modulation, alveolar-capillary membrane stabilization, pulmonary smooth muscle relaxation, reduced neutrophil infiltration

Feedback intact?

Endogenous protein at baseline; supplementation amplifies

Yes — exogenous VIP acts as physiological agonist

Origin

17-AA active fragment of endogenous 43-AA thymosin β4 (TMSB4X gene)Goldstein 2012

Endogenous 28-amino-acid neuropeptide; synthetic analogue (aviptadil) identical to natural VIP

Antibody development

—

02Dosage Protocols

Parameter

TB-500

VIP

Standard dose

2 mg per injectionGoldstein 2012

Anecdotal community range; clinical Phase 2 trials used 70–840 mcg/kg IV.

—

Frequency

2× per week (loading); then 1× per week (maintenance)

—

Lower / starter dose

1 mg per injection

—

Evidence basis

Animal-strong + Phase 2 dermal/ocular trialsGoldstein 2012

Phase 3 RCT (TESICO)Brown 2023

816-patient randomized controlled trial in COVID-19 ARDS.

Duration

4–8 weeks loading; longer maintenance for chronic injury

—

Reconstitution

Bacteriostatic water, 1–2 mL per 5 mg vial

Lyophilized powder reconstituted with sterile diluent per protocol

Timing

Evening or pre-rest preferred (anecdotal)

—

Half-life

~2 hours (estimated; tissue uptake longer)

~2 minutes (plasma)

Rapid clearance necessitates continuous infusion.

Intravenous (ARDS protocol)

—

60–90 mcg/kg/day via continuous infusion

TESICO trial protocol for COVID-19 ARDS.

Infusion duration

—

12-hour continuous IV infusion dailyBrown 2023

Inhaled (investigational)

—

Variable dosing under clinical trial protocolsBoesing 2022

Delivered via nebulizer for direct pulmonary deposition.

Treatment duration

—

3–14 days (acute ARDS)

04Side Effects & Safety

Parameter

TB-500

VIP

Injection site reaction

Mild erythema, transient pain

—

GI symptoms

Rare nausea (anecdotal)

Nausea, diarrhea (VIP is endogenous GI peptide)

Cancer risk

Theoretical via angiogenesis pathway

—

Lethargy / fatigue

Reported anecdotally during loading phase

—

Antibody formation

No data (no long-term human trials)

—

Pregnancy / OB

Avoid

—

Long-term safety

Unknown beyond Phase 2

—

Hypotension

—

Transient vasodilation-related blood pressure drop

Tachycardia

—

Reflex tachycardia secondary to vasodilation

Infusion site reactions

—

Erythema, phlebitis (IV administration)

Overall tolerability

—

Well-tolerated in Phase 3 trials; adverse event profile comparable to placebo

Absolute Contraindications

TB-500

·Active malignancy (theoretical angiogenesis concern)
·Pregnancy / breastfeeding

VIP

·Known hypersensitivity to aviptadil or formulation components

Relative Contraindications

TB-500

·Cancer history
·Concurrent VEGF inhibitor therapy

VIP

·Severe hypotension or shock states (monitor blood pressure)
·Pregnancy — insufficient safety data

05Administration Protocol

Parameter

TB-500

VIP

1. Reconstitution

Add 1–2 mL bacteriostatic water to 5 mg vial → 2.5–5 mg/mL. Roll gently.

Reconstitute lyophilized aviptadil powder with sterile diluent per manufacturer protocol. Inspect solution for particulates — should be clear and colorless.

2. Injection site

SQ near injury site (preferred), or systemic SQ (abdomen). Rotate sites.

Administer as continuous 12-hour intravenous infusion via central or peripheral line. Use infusion pump for precise dosing (60–90 mcg/kg/day divided over infusion duration).

3. Timing

Evening or pre-sleep is most common anecdotal timing.

Monitor blood pressure, heart rate, and oxygenation continuously during first infusion. Assess for hypotension and adjust infusion rate if needed.

4. Storage

Lyophilised: room temp, light-protected. Reconstituted: refrigerate, ≤30 days.

Deliver via jet or mesh nebulizer per clinical trial protocol. Patient seated upright, normal tidal breathing for 10–15 minutes.

5. Needle

27–31G, 4–8 mm insulin syringe.

Store lyophilized powder at 2–8 °C, light-protected. Reconstituted solution: use immediately or within 24 hours if refrigerated.

06Stack Synergy

TB-500

+ BPC-157

Strong

View BPC-157 →

TB-500 and BPC-157 cover complementary halves of tissue repair: BPC-157 upregulates VEGFR2-driven angiogenesis and fibroblast outgrowth; TB-500 sequesters G-actin to enable endothelial / epithelial migration. The anecdotal canonical "healing stack" — pairs especially well for tendon and ligament injuries.

TB-500: 2 mg SQ · 2× per week
BPC-157: 250–500 mcg SQ · daily
Primary benefit: Combined angiogenesis + cell migration for tendon/ligament/muscle repair

VIP

— no documented stacks