What Are Peptides?
Peptides are short chains of amino acids, typically containing between 2 and 50 amino acids linked together by peptide bonds. They are essentially smaller versions of proteins—while proteins contain 50 or more amino acids, peptides are more compact and often more easily absorbed by the body.
How Do Peptides Work?
Peptides act as signaling molecules in the body. They bind to receptors on cell surfaces and trigger specific biological responses. Different peptides target different receptors, which is why they can have such varied effects.
When a peptide binds to its receptor, it initiates a cascade of cellular events that can influence everything from hormone production to tissue repair.
Types of Peptides
Signal Peptides
These peptides send messages between cells, triggering specific responses like collagen production or immune activation.
Carrier Peptides
Carrier peptides transport essential trace elements like copper and manganese to cells where they're needed for various biological processes.
Neurotransmitter Peptides
These affect brain chemistry and can influence mood, cognition, and behavior. Examples include certain nootropic peptides.
Antimicrobial Peptides
Part of the innate immune system, these peptides help fight off bacterial, viral, and fungal infections.
Hormone Peptides
Many hormones are actually peptides, including insulin, growth hormone-releasing hormones, and GLP-1 analogs.
Common Research Peptides
BPC-157 (Body Protection Compound)
A pentadecapeptide composed of 15 amino acids. It's derived from a protein found in gastric juice and has been studied for its potential regenerative properties.
TB-500 (Thymosin Beta-4 Fragment)
A synthetic version of a naturally occurring peptide present in virtually all human and animal cells. Research focuses on its role in tissue repair.
Semaglutide
A GLP-1 receptor agonist that mimics the incretin hormone GLP-1. It's been extensively studied for metabolic research.
Ipamorelin
A growth hormone secretagogue that selectively stimulates growth hormone release without significantly affecting cortisol or prolactin levels.
GHK-Cu (Copper Peptide)
A naturally occurring copper complex that has been researched for its potential role in skin health and wound healing.
Peptides vs. Proteins
| Feature | Peptides | Proteins |
|---|---|---|
| Size | 2-50 amino acids | 50+ amino acids |
| Structure | Linear or simple | Complex 3D folding |
| Absorption | Generally easier | Requires digestion |
| Stability | Less stable | More stable |
How Are Peptides Made?
Research peptides are synthesized using solid-phase peptide synthesis (SPPS), a method developed by Bruce Merrifield that earned him the Nobel Prize. This process builds peptides one amino acid at a time on a solid support, allowing for precise control over the sequence.
After synthesis, peptides undergo purification (typically HPLC) and quality testing to verify purity and identity.
Storage and Handling
Peptides are typically supplied in lyophilized (freeze-dried) form for stability. In this state, they can be stored long-term in a freezer. Once reconstituted with bacteriostatic water, they must be refrigerated and used within a specific timeframe.
Frequently Asked Questions
What are peptides made of?
Peptides are made of amino acids linked together by peptide bonds. The sequence and number of amino acids determines the peptide's specific properties and function.
What is the difference between peptides and proteins?
The main difference is size: peptides contain 2-50 amino acids while proteins contain 50 or more. Proteins also have complex 3D structures, while peptides are typically linear or have simpler structures.
How are peptides stored?
Lyophilized (freeze-dried) peptides should be stored in a freezer at -20°C for long-term storage. Once reconstituted with bacteriostatic water, store in a refrigerator at 2-8°C and use within 4-6 weeks.
Need Help with Dosing?
Use our calculator to determine exact amounts for your research.
Peptide Calculator