Living+Peptides

Guides

Start with the basics

Short guides for anyone trying to make sense of peptides: what they are, how to judge the research, what FDA says about safety, and how peptide drugs are prescribed. Each one cites the government and journal records it draws on.

By Living+. Last updated October 25, 2026.

A peptide drawn as a chain of twelve amino acids
A peptide is a short chain of amino acids, typically 2 to 50 of them. FDA counts 40 or fewer as a peptide; longer chains are proteins.

  1. New to peptides?

    What is a peptide?

    What a peptide is, how it differs from a protein, and where FDA draws the line between them.

    Inside

    • Amino acids are the building blocks
    • Peptides vs proteins
    • Natural peptides in the body
    • Peptide drugs
    • Unapproved peptides

    Peptides it mentions

    3 min read8 sourcesRead the guide

  2. Looking at a study?

    How to read a peptide study

    How to tell a lab, animal or human study apart, and what to check before trusting a result.

    Inside

    • Lab, animal or human?
    • Clinical trials vs observational studies
    • Randomized and blinded trials
    • Sample size and trial phases
    • Reading a ClinicalTrials.gov record
    • A quick checklist

    Peptides it mentions

    4 min read9 sourcesRead the guide

  3. Thinking about the risks?

    Peptide safety basics

    The safety concerns FDA has named for unapproved and compounded peptides, and how to report a problem.

    Inside

    • Risks FDA names for unapproved peptides
    • Risks FDA names for compounded drugs
    • Injection risks
    • Immune and allergic reactions
    • How to report a problem to FDA

    Peptides it mentions

    3 min read6 sourcesRead the guide

  4. How do peptide drugs reach patients?

    How peptides are prescribed in the US

    Approved prescriptions, off-label use, compounding pharmacies and the telehealth rules.

    Inside

    • Path 1: FDA-approved peptide drugs
    • Path 2: Compounded peptide drugs
    • Which peptides a 503A pharmacy may use
    • Compounded copies of approved peptide drugs
    • Telehealth prescribing rules

    Peptides it mentions

    3 min read10 sourcesRead the guide