What Are Peptides? A Complete Introduction

Peptides are short chains of amino acids linked together by peptide bonds. They are essentially smaller versions of proteins—while proteins typically contain 50 or more amino acids, peptides usually contain between 2 and 50 amino acids.

Your body naturally produces thousands of peptides that serve as signaling molecules, hormones, and building blocks for various biological functions. Synthetic peptides mimic these natural molecules and are used in research, medicine, and cosmetics.

Key points:

• Peptides are chains of 2-50 amino acids
• Your body naturally produces many peptides
• Synthetic peptides can mimic natural functions
• Different from proteins (which are larger)

Peptides work by binding to specific receptors on cell surfaces, triggering cellular responses. Think of them as "keys" that fit into specific "locks" (receptors) to activate or modulate biological pathways.

Common mechanisms include:

1. Receptor Activation - Binding to cell surface receptors to trigger signaling cascades
2. Enzyme Inhibition - Blocking enzymes that break down beneficial compounds
3. Gene Expression - Influencing which genes are turned on or off
4. Hormone Mimicry - Mimicking the effects of natural hormones

Because peptides are highly specific—each peptide typically only fits certain receptors—they can produce targeted effects with potentially fewer off-target side effects than broader-acting drugs.

Peptides are categorized by their function and origin:

By Function:

• Growth Hormone Secretagogues - Stimulate natural GH production (e.g., CJC-1295, Ipamorelin)
• Healing Peptides - Promote tissue repair (e.g., BPC-157, TB-500)
• Metabolic Peptides - Affect metabolism and weight (e.g., Semaglutide, Tirzepatide)
• Cognitive Peptides - Support brain function (e.g., Selank, Semax)
• Cosmetic Peptides - Used in skincare (e.g., GHK-Cu, Argireline)
• Immune Peptides - Modulate immune function (e.g., Thymosin Alpha-1)

By Regulatory Status:

• FDA-Approved - Approved for specific medical uses (e.g., Semaglutide, Tesamorelin)
• Research Peptides - Available for research purposes only
• Cosmetic Peptides - Used in skincare products

Peptides are often confused with anabolic steroids, but they are fundamentally different:

Peptides typically work by stimulating your body's own processes (like growth hormone production), while steroids directly provide exogenous hormones. This fundamental difference affects their safety profiles and effects.

The research status of peptides varies widely:

Well-Researched (Human Trials):

• GLP-1 agonists (Semaglutide, Tirzepatide)
• Sermorelin
• Tesamorelin
• PT-141 (Bremelanotide)

Limited Human Research:

• BPC-157 (extensive animal data, limited human)
• TB-500 (animal studies only)
• Most growth hormone secretagogues

Important Considerations:

• Many peptides lack long-term safety data
• Quality varies significantly between sources
• Individual responses can differ
• Medical supervision is recommended

Always consult with a healthcare provider before using any peptide for therapeutic purposes.