Peptide Basics
What peptides are, how they work, and why people use them
About 8 minutes
What Are Peptides?
Peptides are short chains of amino acids — typically between 2 and 50 amino acids long. They're smaller than proteins but play critical roles in biological signaling, acting as hormones, neurotransmitters, and growth factors.
Your body naturally produces many peptides. Synthetic peptides are lab-made versions designed to mimic or enhance these natural signals.
How Do Peptides Work?
Peptides work by binding to specific receptors on cells, triggering biological responses. Different peptides target different receptors, which is why each peptide has unique effects.
Common Categories
Peptides are commonly grouped by their primary function:
- Growth Hormone Secretagogues (GHS) — stimulate natural GH release (e.g., CJC-1295, Ipamorelin; MK-677 is in this class but is an oral non-peptide compound)
- Fat Loss / Metabolic — target metabolism and fat burning (e.g., Tirzepatide, Semaglutide, AOD-9604)
- Healing & Recovery — support tissue repair (e.g., BPC-157, TB-500, GHK-Cu)
- Immune & Longevity — modulate immune function and aging (e.g., Thymosin Alpha-1, Epitalon)
- Cognitive & Sleep — improve mental function and rest (e.g., Selank, DSIP, Semax)
Why People Use Peptides
People explore peptides for a range of goals: recovery from injuries, body composition improvement, better sleep, enhanced cognition, anti-aging, and immune support.
Key Terminology
Terms you'll encounter frequently:
- Reconstitution — mixing lyophilized (freeze-dried) peptide powder with bacteriostatic water
- SubQ — subcutaneous injection, under the skin into fatty tissue
- IM — intramuscular injection, into muscle tissue
- mcg — microgram, 1/1000th of a milligram. Most peptides are dosed in mcg
- IU — International Units, used for some peptides like HGH
- Lyophilized — freeze-dried powder form, how most peptides ship
- BAC water — bacteriostatic water, sterile water with 0.9% benzyl alcohol preservative