Peptide Comparison
VIP (Vasoactive Intestinal Peptide)vsThymosin Beta-4
Endogenous neuropeptide with vasodilatory, anti-inflammatory, and immunomodulatory properties
The body's natural healing peptide that accelerates tissue repair and reduces inflammation
At a Glance
Quick
comparison
Dose Range
VIP (Vasoactive Intestinal Peptide)
67 mcg/day–300 mcg/day mcg
Thymosin Beta-4
2–5 mg
Frequency
VIP (Vasoactive Intestinal Peptide)
Once daily
Thymosin Beta-4
Twice weekly
Administration
VIP (Vasoactive Intestinal Peptide)
Intravenous infusion
Thymosin Beta-4
Subcutaneous injection
Cycle Length
VIP (Vasoactive Intestinal Peptide)
Ongoing/indefinite
Thymosin Beta-4
8-12 weeks
Onset Speed
VIP (Vasoactive Intestinal Peptide)
Moderate (1-2 weeks)
Thymosin Beta-4
Moderate (1-2 weeks)
Evidence Level
VIP (Vasoactive Intestinal Peptide)
Moderate human trials (Phase 1-2)
Thymosin Beta-4
Moderate human trials (Phase 1-2)
Efficacy
Benefit
ratings
Cardiovascular
Anti-Inflammatory
Neuroprotection
Wound Healing
Inflammation Reduction
Tissue Regeneration
Technical Data
Compound
specifications
VIP (Vasoactive Intestinal Peptide)
Molecular Formula
C147H237N43O43S
Molecular Weight
3325.83 Da
Half-Life
Approximately 1-2 minutes in plasma (rapid enzymatic degradation)
Bioavailability
IV: 100%; Inhaled: local pulmonary delivery; short systemic half-life
CAS Number
37221-79-7
Thymosin Beta-4
Molecular Formula
C212H350N56O78S
Molecular Weight
4963
Half-Life
Dose-dependent (increases with higher doses)
Bioavailability
100% (subcutaneous and intravenous)
CAS Number
77591-33-4
Applications
Best
suited for
VIP (Vasoactive Intestinal Peptide)
Pulmonary arterial hypertension research
VIP (Vasoactive Intestinal Peptide) is particularly well-suited for individuals focused on pulmonary arterial hypertension research. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
ARDS and respiratory failure investigation
VIP (Vasoactive Intestinal Peptide) is particularly well-suited for individuals focused on ards and respiratory failure investigation. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Anti-inflammatory therapy development
VIP (Vasoactive Intestinal Peptide) is particularly well-suited for individuals focused on anti-inflammatory therapy development. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Neuroprotection studies
VIP (Vasoactive Intestinal Peptide) is particularly well-suited for individuals focused on neuroprotection studies. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Thymosin Beta-4
Post-Surgery Recovery
Accelerates healing of surgical wounds and reduces post-operative inflammation and scarring
Chronic Wound Management
Helps pressure ulcers, venous stasis ulcers, and other slow-healing wounds progress faster
Tissue Regeneration
Supports repair of damaged tissues from injury, burns, or degenerative conditions
Safety Profile
Side
effects
VIP (Vasoactive Intestinal Peptide)
Common
- Facial Flushing
- Diarrhea
- Nausea
Uncommon
- Hypotension
- Tachycardia
- Cardiovascular Effects
Serious
- Hypotension
- Severe Flushing and Facial Erythema
Thymosin Beta-4
Common
- Injection site redness
- Injection site swelling
Uncommon
- Temporary mild headache
- Mild bruising at injection site
- Transient fatigue
Serious
- Allergic reaction
Research Status
Safety
& evidence
VIP (Vasoactive Intestinal Peptide)
Evidence Level
Moderate human trials (Phase 1-2)
FDA Status
Research compound
Safety Overview
VIP (Vasoactive Intestinal Peptide) is a 28-amino acid endogenous neuropeptide with moderate evidence from Phase 1-2 human clinical trials. The synthetic pharmaceutical form (aviptadil/RLF-100) received FDA fast-track designation for COVID-19-associated ARDS, indicating recognition of its therapeutic potential. Critical safety considerations: VIP is a potent vasodilator that causes dose-dependent hypotension and compensatory tachycardia—hemodynamic monitoring is essential during IV administration. Common side effects include facial flushing and diarrhea from its GI effects. Phase 2b/3 COVID-19 ARDS trials (196 patients) reported NO serious drug-related adverse events, a favorable safety signal. However, individual responses to vasodilation vary significantly based on baseline cardiovascular status, medications, and underlying conditions. The peptide's short plasma half-life (1-2 minutes) limits systemic accumulation. Inhaled VIP shows excellent local tolerability for pulmonary applications with minimal systemic absorption.
Contraindications
- xUncontrolled hypotension or hemodynamic instability
- xSevere cardiac decompensation
- xNot approved for clinical use outside of trials
- xInsufficient data for pregnancy and lactation safety
Thymosin Beta-4
Evidence Level
Moderate human trials (Phase 1-2)
FDA Status
Research compound
Safety Overview
Thymosin Beta-4 is a naturally occurring peptide found in all cells and body fluids in the human body. Clinical trials have demonstrated excellent safety even at very high doses. IV studies showed doses up to 1260 mg were well tolerated with no serious adverse events.
Contraindications
- xActive systemic infections
- xSevere immunosuppression
- xHypersensitivity to thymosin or any component
- xPregnancy (insufficient safety data)
Decision Guide
Which is
right for you?
Choose VIP (Vasoactive Intestinal Peptide) if...
- Pulmonary arterial hypertension research
- ARDS and respiratory failure investigation
- Anti-inflammatory therapy development
- Neuroprotection studies
Choose Thymosin Beta-4 if...
- Recovering from injuries or surgery
- Improving wound healing speed
- Reducing inflammation
- Minimizing scar formation