Peptide Comparison
Apelin-13vsTB-500
A natural heart hormone that helps your cardiovascular system work better and supports healthy blood flow throughout your body.
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
Apelin-13
As prescribed–As prescribed mg
TB-500
2–5 mg
Frequency
Apelin-13
Once daily
TB-500
Twice weekly
Administration
Apelin-13
Intravenous (IV)
TB-500
Subcutaneous injection
Cycle Length
Apelin-13
Ongoing/indefinite
TB-500
4-6 weeks
Onset Speed
Apelin-13
Moderate (1-2 weeks)
TB-500
Moderate (1-2 weeks)
Evidence Level
Apelin-13
Moderate human trials (Phase 1-2)
TB-500
Moderate human trials (Phase 1-2)
Efficacy
Benefit
ratings
Cardiovascular Support
Heart Function & Strength
Blood Flow & Circulation
Healing Speed
Tissue Repair
Anti-Scarring
Technical Data
Compound
specifications
Apelin-13
Molecular Formula
C69H111N23O16S
Molecular Weight
1550.8 Da
Half-Life
Minutes in plasma; varies by route of administration
Bioavailability
~90-95% (subcutaneous injection)
CAS Number
Not yet assigned (research compound)
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
Apelin-13
TB-500
Applications
Best
suited for
Apelin-13
Research into cardiovascular health and heart function
Apelin-13 is particularly well-suited for individuals focused on research into cardiovascular health and heart function. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Understanding how the body naturally protects the heart
Apelin-13 is particularly well-suited for individuals focused on understanding how the body naturally protects the heart. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Exploring potential treatments for heart failure
Apelin-13 is particularly well-suited for individuals focused on exploring potential treatments for heart failure. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Studying mechanisms of heart muscle strength
Apelin-13 is particularly well-suited for individuals focused on studying mechanisms of heart muscle strength. 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
Apelin-13
Common
- Mild changes in blood pressure
- Minimal systemic effects in animal studies
- Headache (theoretical, based on blood pressure effects)
- Flushing or warmth at injection site
- Mild inflammation at injection site
- Dizziness if blood pressure drops too quickly
- Allergic reactions to the peptide
- Heart rhythm changes (requires monitoring)
- Blood pressure, heart rate, cardiac function
Serious
- Severe allergic reaction
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
Apelin-13
Evidence Level
Moderate human trials (Phase 1-2)
FDA Status
Research compound
Safety Overview
Apelin-13 is a research compound with no human clinical trials or FDA approval. All safety data comes from animal studies and in vitro mechanistic work showing beneficial effects on vascular function and cardiac remodeling. However, animal models do not predict human safety, and the peptide's effects on immune regulation in humans remain untested. No dose-ranging studies, pharmacokinetics, or organ accumulation data exist in humans. The APJ receptor is expressed in multiple tissues including brain, raising concerns about off-target neurological effects at high doses.
Contraindications
- xCurrently under investigation - not for human clinical use
- xMay interact with blood pressure medications (in theory)
- xShould not be used if allergic to peptides or component amino acids
- xPregnant or breastfeeding individuals should avoid
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 Apelin-13 if...
- Research into cardiovascular health and heart function
- Understanding how the body naturally protects the heart
- Exploring potential treatments for heart failure
- Studying mechanisms of heart muscle strength
Choose TB-500 if...
- Accelerating injury recovery
- Tendon and ligament healing
- Reducing chronic inflammation
- Post-surgical recovery support