§ 01 What is a peptide?
Think of it this way: if proteins are sentences, then peptides are words.
Both are made from the same alphabet — amino acids. Your body has 20 different amino acids that link together in chains. A short chain (under ~50 amino acids) is called a peptide. A long chain (50+) is called a protein.
Your body naturally produces thousands of peptides. They act as chemical messengers — tiny signals that tell your cells what to do. Insulin (controls blood sugar) is a peptide. Oxytocin (the "bonding hormone") is a peptide. Endorphins (natural painkillers) are peptides.
§ 02 How do peptides work?
Peptides work like keys fitting into locks. Your cells have receptors (the locks) on their surface. When the right peptide (the key) binds to a receptor, it triggers a specific response inside the cell.
This is why peptides are so specific — each one only fits certain receptors. BPC-157 interacts with growth factor receptors (triggering tissue repair). Semaglutide fits GLP-1 receptors (controlling appetite). Ipamorelin binds ghrelin receptors (releasing growth hormone).
§ 03 Why are people interested?
Peptides sit at the intersection of cutting-edge medicine and biohacking culture. Some are FDA-approved medications (semaglutide, tirzepatide). Others are research compounds used off-label by people trying to optimise their health.
Healing & Recovery
Accelerating tissue repair, reducing inflammation, wound healing.
e.g. BPC-157, TB-500, GHK-Cu
Longevity & Anti-Aging
Telomere maintenance, mitochondrial function, cellular repair.
e.g. Epithalon, MOTS-c, SS-31, NAD+
Cognition & Mood
Memory, focus, anxiety, sleep quality, neuroprotection.
e.g. Semax, Selank, DSIP, PE-22-28
Body Composition
Fat loss, muscle preservation, metabolic optimisation.
e.g. Semaglutide, Tirzepatide, CJC/Ipa
Important distinction
FDA-approved peptides (like semaglutide) have gone through rigorous clinical trials. Most peptides in the biohacking space have not. "Research chemical" means exactly that — the research is ongoing and incomplete.
§ 04 How to read peptide research
Not all evidence is created equal. When someone says "studies show...", your first question should be: what kind of studies?
A study of studies. Combines results from multiple trials to find patterns. The gold standard of evidence.
Randomised controlled trials in actual humans. Double-blind, placebo-controlled trials are the most reliable.
Tested in mice, rats, rabbits. Promising but doesn't always translate to humans. Most BPC-157 data lives here.
Done in test tubes or cell cultures. Can show a mechanism in theory, but cells in a dish aren't a human body.
On every peptide page, we show evidence-level badges so you always know how strong the science actually is. Don't let anyone sell you in-vitro results as proven medicine.
§ 05 Glossary
Key terms you'll see across the site. Bookmark this section.
- Amino Acid
- The building blocks of peptides and proteins. There are 20 standard amino acids that combine in different sequences to create different peptides.
- Receptor
- A protein on a cell's surface that a peptide binds to, like a lock receiving a key. This binding triggers a specific response inside the cell.
- Half-Life
- The time it takes for half of a peptide to be broken down and cleared from your body. Short half-life = frequent dosing needed.
- Subcutaneous (SubQ)
- An injection into the fat layer just under the skin. The most common administration route for peptides.
- Bioavailability
- The percentage of a substance that actually reaches the bloodstream. Oral peptides have low bioavailability because stomach acid breaks them down.
- Angiogenesis
- The formation of new blood vessels. Some peptides (like BPC-157) promote this to speed healing.
- Secretagogue
- A substance that stimulates a gland to secrete something. Growth hormone secretagogues make the pituitary release more GH.
- Agonist
- A molecule that activates a receptor to produce a biological response. GLP-1 agonists mimic the GLP-1 hormone.
- Telomere
- Protective caps on the ends of chromosomes. They shorten with age. Some peptides (like Epithalon) may help maintain them.
- Neuropeptide
- A peptide that acts on the nervous system. Examples include DSIP (sleep), Selank (anxiety), and Semax (cognition).
- IGF-1
- Insulin-like Growth Factor 1. Produced by the liver in response to growth hormone. Many GH-related peptides are measured by their effect on IGF-1 levels.
- In Vitro
- Latin for 'in glass.' Experiments done in test tubes or petri dishes, outside a living organism. The lowest level of evidence.
⚠ Informational only
This guide is educational. It is not medical advice. Always consult a qualified clinician before making any health decision.