Reading room · 41 articles
Peptides Explained With the Evidence Behind Every Claim
Peptides are short chains of amino acids, the same building blocks as proteins. Some are approved medicines, such as insulin and semaglutide. Many others, including BPC-157, GHK-Cu and retatrutide, have little or no human approval. Every guide here states which kind of evidence stands behind a claim: approved labels, human trials, or only cell and animal studies.
- Approved label
- Human trials
- Cell and animal studies
Start here
Peptide guides by compound
Weight loss
Healing and recovery
Growth hormone
Skin and anti-aging
Longevity and metabolism
- Basics 8 What peptides are, how they are made and how to read the studies about them.
- Weight Loss Peptides 8 Approved GLP-1 medicines, drugs still in trials and compounds with little human data.
- Healing and Recovery 3 Peptides promoted for injury and repair, most of them studied only in animals.
- Growth Hormone Peptides 5 Compounds that act on growth hormone release, one of them an approved medicine.
- Skin and Anti-Aging 6 Copper peptides, serums, collagen supplements and what their trials measured.
- Longevity and Wellness 7 Peptides sold for ageing, energy and wellness, from approved drugs to cell studies.
- Safety and Quality 4 Storage, certificates of analysis and how to spot unreliable sellers.
Latest articles
Safety and QualityAnti-Doping 101: Why Some Peptides Are Banned
Healing and RecoveryPeptides and Recovery: A Research Overview
Skin and Anti-AgingSkincare Peptides: Serum Science vs Marketing
Skin and Anti-AgingCollagen Peptides: What Science Actually Says About Skin
BasicsNature's Antibiotics: The Promise of Antimicrobial Peptides
BasicsHow Labs Build a Peptide, One Amino Acid at a Time
How we check facts
Every article is checked against primary sources:
- Regulator pages
- Drug labels
- PubMed records
- Clinical trial registries
- The anti-doping list
We never recommend doses or sellers, and we have no sponsors or affiliate links.
The rules are set out in our editorial policy, and the about page explains how the site works.
Peptide questions answered briefly
See all questionsWhat are peptides?
Short chains of amino acids, usually 2 to about 50 units long. Longer chains are called proteins.
Full guide: What are peptidesAre peptides safe?
It depends. Approved medicines like insulin have passed safety trials, while products sold as research chemicals are not checked to medicine standards.
Full guide: How to spot unreliable sourcesAre peptides steroids?
No. Peptides are chains of amino acids, while steroids are fat-soluble molecules built on four carbon rings.
Full guide: Are peptides steroidsIs retatrutide FDA approved?
Not as of October 2026. It is an investigational Eli Lilly drug, and products sold online as retatrutide are not the trial medicine.
Full guide: Retatrutide status and safety facts