ProPep

Understanding Peptides

A plain-language guide to what peptides are and why they are being extensively researched.

The Peptide Library

Peptides are the subject of ongoing research across many areas of health. Start with a topic that interests you, then explore an individual compound to see what the evidence says, and what it doesn't.

Explore the library by name or interest. Every profile separates biological mechanisms, evidence and product-specific regulatory context.

14 of 14 profiles. Topics describe areas of study, not treatment recommendations; evidence filters are navigation aids, not quality scores.

  • Clinical evidence

    Semaglutide

    Wegovy • Ozempic • Rybelsus

    A GLP-1 receptor agonist used in specific prescription medicines for defined indications.

    Weight & metabolism
  • Clinical evidence

    Tirzepatide

    Zepbound • Mounjaro

    A dual-receptor agonist with evidence tied to specific prescription products and patient groups.

    Weight & metabolism
  • Investigational human research

    Retatrutide

    LY3437943

    An investigational compound acting at GIP, GLP-1 and glucagon receptors.

    Weight & metabolism
  • Preclinical / limited evidence

    GHK-Cu

    Copper tripeptide-1 • glycyl-histidyl-lysine copper

    A copper-bound tripeptide studied in skin biology and extracellular-matrix research.

    Skin, hair & aesthetics
  • Preclinical / limited evidence

    AHK-Cu

    Alanyl-histidyl-lysine copper

    A distinct copper tripeptide studied in cultured hair follicles and dermal-papilla cells.

    Skin, hair & aesthetics
  • Preclinical / limited evidence

    BPC-157

    Body protection compound 157

    An experimental compound discussed in tissue-repair research, with major clinical evidence gaps.

    Recovery & tissue research
  • Clinical evidence

    SS-31 / Elamipretide

    Forzinity • elamipretide

    A compound associated with a specific US medicine for Barth syndrome—not general anti-aging approval.

    Cellular science & aging
  • Preclinical / limited evidence

    5-Amino-1MQ

    5-amino-1-methylquinolinium

    A small-molecule NNMT inhibitor included for clarity because it appears in peptide catalogues.

    Weight & metabolism
  • Investigational human research

    CJC-1295

    Verify the exact molecular form

    A growth-hormone-pathway compound whose molecular form matters when interpreting research.

    Muscle & body composition
  • Investigational human research

    Ipamorelin

    Ipamorelin acetate

    An investigational compound discussed in growth-hormone signaling and combination-product marketing.

    Muscle & body composition
  • Preclinical / limited evidence

    TB-500 / Tβ4 fragment

    Commercial naming requires verification

    A research-market name that must be distinguished from full-length thymosin beta-4.

    Recovery & tissue research
  • Clinical evidence

    Tesamorelin

    Egrifta product family

    A prescription compound with a specific visceral-fat indication, not a general weight-loss indication.

    Muscle & body composition
  • Preclinical / limited evidence

    Adamax

    Semax-derived research compound

    A synthetic research peptide described by suppliers as a modified analogue of Semax, investigated for interest in cognition and nerve-cell signalling.

    Cognition, sleep & mood
  • Preclinical / limited evidence

    PT-141

    PT-141 is a research compound supplied for laboratory and scientific study.

    Cellular science & aging
Compound field guide · Weight & metabolism

Retatrutide

LY3437943

Investigational human research

An investigational compound acting at GIP, GLP-1 and glucagon receptors.

Investigational peptide • triple receptor agonist

Product & jurisdiction matter

US: the FDA advisory states retatrutide is not a component of an FDA-approved drug and cannot be used in compounding under federal law.

Trinidad & Tobago product registration and supply authorization have not been verified. US status is reference context only.

How it works

Designed to activate three receptor pathways: GIP, GLP-1 and glucagon. Researchers investigate how this combination affects weight and metabolism.

What the evidence shows

A randomized phase 2 obesity trial published in 2023 reported weight reduction. Gastrointestinal adverse events and increases in heart rate were observed. This is a selected study, not a claim to summarize every subsequent trial.

What it does not establish

Trial participation involves a controlled investigational product and monitoring. Results do not validate products marketed online as retatrutide or establish individual suitability.

Safety & unanswered questions

The cited trial reported gastrointestinal effects and heart-rate increases. Broader and longer-term safety questions require continuing investigation.

A useful question to ask

Is a claim based on a controlled trial, or on an unverified commercial product?

Read the sources

  1. Randomized phase 2 trial · NEJM, 2023 (opens in a new tab)
  2. FDA · unapproved GLP-1 products (opens in a new tab)

Educational information, not a treatment recommendation or instructions for use. Research peptides are sold for laboratory research only.

Keep exploring

Available as a research peptide:AMP-3P

The Basics

You don't need a science degree to ask better questions.

  • What is a peptide?

    A peptide is a chain of amino acids linked by peptide bonds. Different sequences can have very different biological roles, so “peptide” describes a molecular family, not a guarantee of effectiveness or safety.

    Some are naturally occurring signals; others are designed medicines or experimental compounds. Not everything sold as a peptide actually is one: 5-Amino-1MQ, for example, is a small molecule.

  • How do peptides work?

    Some interact with receptors, the proteins that receive biological signals. Others are investigated for interactions with cellular structures or enzymes. The effect depends on the exact molecule, formulation, exposure and biological context.

    A plausible mechanism is the beginning of an explanation. Showing a meaningful benefit requires appropriate studies in people, not just evidence that a pathway changed.

  • What counts as evidence?

    Laboratory studies of cells or tissues help explore mechanisms, and animal studies examine effects in living models. Neither proves a benefit in people.

    For human trials, ask who was studied, whether there was a comparison group, what was measured and for how long. A change in a hormone or biomarker may not mean better health or performance.

  • Does an approved molecule mean an approved vial?

    No. Approval concerns a particular product, formulation and use within a country. A research vial with a matching compound name does not inherit that approval.

    US status is given as reference context. Registration, importation and supply in Trinidad and Tobago are matters for the Chemistry, Food and Drugs Division.

For Education Only

The information on this page is provided for general educational purposes only. It is not medical advice and is not a substitute for a consultation with a qualified physician. Do not start, stop or change any treatment based on this information.

Research peptides sold by ProPeptide are intended strictly for laboratory and research purposes. They are not approved for human or veterinary use, and are not intended to diagnose, treat, cure or prevent any disease.

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