Peptide Comparison
VIP (Vasoactive Intestinal Peptide)vsTB-500
Endogenous neuropeptide with vasodilatory, anti-inflammatory, and immunomodulatory properties
A powerful fragment of thymosin beta-4 that acts like your body's repair signal—speeding up healing of muscles, tendons, and tissues by promoting cell migration and new blood vessel growth right where you need it most.
At a Glance
Quick
comparison
Dose Range
VIP (Vasoactive Intestinal Peptide)
67 mcg/day–300 mcg/day mcg
TB-500
2–5 mg
Frequency
VIP (Vasoactive Intestinal Peptide)
Once daily
TB-500
Twice weekly
Administration
VIP (Vasoactive Intestinal Peptide)
Intravenous infusion
TB-500
Subcutaneous injection
Cycle Length
VIP (Vasoactive Intestinal Peptide)
Ongoing/indefinite
TB-500
4-6 weeks
Onset Speed
VIP (Vasoactive Intestinal Peptide)
Moderate (1-2 weeks)
TB-500
Moderate (1-2 weeks)
Evidence Level
VIP (Vasoactive Intestinal Peptide)
Moderate human trials (Phase 1-2)
TB-500
Moderate human trials (Phase 1-2)
Efficacy
Benefit
ratings
Cardiovascular
Anti-Inflammatory
Neuroprotection
Healing Speed
Tissue Repair
Anti-Scarring
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
TB-500
Molecular Formula
C38H68N10O14
Molecular Weight
889.01 g/mol
Half-Life
2-3 days (systemic)
Bioavailability
High via subcutaneous injection (~100%)
CAS Number
885340-08-9
Protocols
Dosing
tiers
VIP (Vasoactive Intestinal Peptide)
TB-500
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.
TB-500
Athletes Recovering from Muscle Injuries
If you've pulled a hamstring, strained your back, or torn a muscle, TB-500 helps accelerate the healing process by promoting cell migration to the injury site and supporting new blood vessel growth. It's especially useful for injuries that just won't seem to fully heal.
Tendon and Ligament Problems
Tendons and ligaments are notoriously slow healers because they have poor blood supply. TB-500 promotes angiogenesis (new blood vessel formation) and helps repair these stubborn connective tissue injuries—think Achilles tendonitis, tennis elbow, or rotator cuff issues.
Post-Surgical Recovery
After surgery, your body needs to repair a lot of tissue quickly. TB-500 supports wound healing, reduces inflammation, and may help minimize scar tissue formation. Some protocols use it alongside traditional recovery to potentially speed up the healing timeline.
Chronic Inflammation and Slow Healers
Some people just heal slowly—whether due to age, diabetes, or other factors. TB-500 helps regulate the inflammatory response and promotes the cellular processes needed for tissue repair. It essentially tells your body to focus healing resources where they're needed most.
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
TB-500
Common
- Injection site redness
- Mild fatigue or lethargy
- Mild headache
- Slight flushing
Uncommon
- Head rush or lightheadedness
- Temporary nausea
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
TB-500
Evidence Level
Moderate human trials (Phase 1-2)
FDA Status
Research compound
Safety Overview
TB-500 has shown a good safety profile across preclinical studies and limited human research. It's a fragment of thymosin beta-4, a naturally occurring protein in your body involved in healing. Most side effects are mild and transient, primarily injection site reactions. However, large-scale clinical trials are still needed to fully establish its safety profile in humans.
Contraindications
- xPregnancy or planning to become pregnant
- xCurrently breastfeeding
- xActive cancer or history of cancer
- xKnown allergy to peptide components
- xChildren and adolescents
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 TB-500 if...
- Accelerating injury recovery
- Tendon and ligament healing
- Reducing chronic inflammation
- Post-surgical recovery support