Reality check
There is no honest static list of every peptide.
The peptide universe is too large to list as a single static article. Human PeptideAtlas alone reports more than 5.3 million distinct human peptides in its 2026 build. A truthful page must work as a map: categories, mechanisms, representative examples, evidence levels, and source databases.
Definition
What is a peptide?
A peptide is a short chain of amino acids joined by peptide bonds — typically about 2–50 amino acids. Proteins are longer folded chains of the same building blocks; the line between “long peptide” and “small protein” is fuzzy. Peptides can be linear, cyclic, disulfide-rich, lipidated, PEGylated, stapled, or conjugated to other molecules. Many peptides are signalling molecules because cells read them through specific receptors.
Peptide universe map
Fifteen categories that cover almost everything called “peptide”.
These categories are how the field thinks about peptides — not how marketing thinks about them. Some categories are mature medicine; some are speculative; some are explicitly grey-market. Evidence varies sharply within each.
Hormonal peptides
Mostly approvedEndogenous signalling peptides that regulate metabolism, growth, reproduction, water balance, and stress.
Why it matters: the deepest, best-studied corner of peptide medicine.
Examples Insulin · Glucagon · GLP-1 · GIP · Oxytocin · Vasopressin · Growth hormone
Neuropeptides
MixedShort peptides used by neurons to modulate mood, pain, appetite, and circadian function.
Why it matters: targets for migraine, depression, addiction, and pain drugs.
Examples Enkephalins · Endorphins · Dynorphins · Substance P · NPY · CGRP · Orexins
Gut peptides
Largely approvedHormones released by the GI tract that regulate appetite, digestion, and gut function.
Why it matters: the basis of GLP-1 obesity and diabetes drugs.
Examples Ghrelin · PYY · CCK · Gastrin · Secretin · VIP · Motilin
Cardiovascular peptides
MixedPeptides regulating blood pressure, vascular tone, and cardiac function. Targets for hypertension and heart failure drugs.
Why it matters: blood pressure regulation and the ANP/BNP biomarker pathway.
Examples Angiotensin II · Bradykinin · Endothelin · ANP · BNP
Immune / antimicrobial peptides
Active researchPeptides used by the innate immune system to kill or restrict bacteria, fungi, viruses, and parasites.
Why it matters: potential antibiotics in a world of growing resistance.
Examples Defensins · Cathelicidin LL-37 · Magainins · Nisin · Polymyxins · Daptomycin (lipopeptide)
Venom and toxin peptides
Several approvedPeptides found in venoms of snakes, snails, scorpions, and other animals. Often potent and selective ion-channel or receptor modulators.
Why it matters: a fertile source of pain and cardiovascular drugs.
Examples Ziconotide (cone snail) · Exenatide (Gila monster lineage) · Bivalirudin (hirudin-derived)
Food-derived bioactive peptides
Early evidenceShort peptides released during digestion of dietary proteins (milk, soy, egg, fish). Some have demonstrated mild bioactivity in food-science studies.
Why it matters: functional foods and nutraceuticals; evidence often modest in vivo.
Examples Casein-derived peptides · Lactoferrin fragments · Soy peptides
Therapeutic peptide drugs
Approved medicinesSynthetic or recombinant peptides developed and approved as prescription medicines, with regulated manufacturing and dosing studies.
Why it matters: over 80 approved peptide medicines globally and ~200 candidates in clinical development.
Examples Semaglutide · Tirzepatide · Octreotide · Teriparatide · Leuprolide · Bivalirudin · Enfuvirtide
Cosmetic peptides
Topical onlyShort synthetic peptides marketed in skincare for collagen support, “anti-ageing”, and wrinkle reduction. Topical application; not the same as injectable peptides.
Why it matters: evidence varies; cosmetic claims are loosely regulated relative to therapeutic claims.
Examples Palmitoyl pentapeptides · Acetyl hexapeptide-8 (Argireline) · GHK-Cu (topical) · Signal peptides
Research / grey-market peptides
High cautionExperimental peptides marketed online — often labelled “research only” — for recovery, performance, longevity, or appearance. Human evidence is limited or absent.
Why it matters: these are the products driving most peptide safety concerns. Avoid unsupervised use.
Examples BPC-157 · TB-500 · CJC-1295 · Ipamorelin · GHRP-2 · GHRP-6 · Melanotan II
Peptide vaccines
EmergingPeptide fragments of pathogen or tumour proteins designed to train the immune system. Active area of cancer-immunotherapy research.
Why it matters: personalised cancer vaccines and antigen-specific therapeutics.
Examples Personalised neoantigen vaccines in clinical trials
Peptide-drug conjugates
Active researchA peptide that targets a specific receptor linked to a small-molecule drug or radioactive payload — delivering therapy where it is needed.
Why it matters: targeted oncology including peptide receptor radionuclide therapy (PRRT).
Examples Octreotide-linked radiopharmaceuticals (e.g., 177Lu-DOTATATE)
Cell-penetrating peptides
Tool peptidesShort peptides that cross cell membranes and can carry other molecules with them. Mostly used as a delivery tool in research and a few therapeutics.
Why it matters: a path into the cell for cargoes that otherwise cannot enter.
Examples TAT · Penetratin · Transportan
Cyclic and macrocyclic peptides
Mature classPeptides whose ends are joined, often gaining stability and the ability to engage protein-protein interfaces that small molecules cannot.
Why it matters: a key technology behind several modern peptide medicines.
Examples Cyclosporine · Octreotide · Pasireotide · Cyclic AMPs
AI-designed peptides
EmergingPeptides whose sequence and structure are designed in silico using machine learning and structural biology models, then synthesised and tested.
Why it matters: a fast-growing source of candidate antimicrobials, binders, and therapeutics.
Examples AlphaFold-supported design pipelines · de novo antimicrobial peptides
Representative peptides
A filterable map of natural, approved, and grey-market peptides.
Search by name, role, or note. Filter by category and evidence status. The list is illustrative, not exhaustive — databases like Human PeptideAtlas, UniProt, APD6, and DBAASP carry the comprehensive records.
| Name | Category | Origin | Main role | Evidence | Note |
|---|---|---|---|---|---|
| Insulin | Endogenous | Natural | Blood-glucose regulation | Approved | Endogenous pancreatic hormone; recombinant analogues are mature medicines. |
| Glucagon | Endogenous | Natural | Raises blood glucose | Approved | Counter-regulatory hormone; used in emergency hypoglycaemia treatment. |
| GLP-1 | Endogenous | Natural | Incretin · insulin release · appetite | Approved | Basis of GLP-1 medicines (semaglutide, liraglutide, exenatide). |
| GIP | Endogenous | Natural | Incretin | Approved (analogue) | Combined with GLP-1 in the dual-agonist tirzepatide. |
| PYY | Endogenous | Natural | Satiety | Clinical evidence | Released by gut after eating; modulates appetite. |
| Ghrelin | Endogenous | Natural | Hunger · GH release | Clinical evidence | The ‘hunger hormone’; analogues researched for cachexia. |
| Oxytocin | Endogenous | Natural | Labour · social bonding | Approved | Endogenous and a medicine for labour induction. |
| Vasopressin | Endogenous | Natural | Water balance · vasoconstriction | Approved (analogues) | Terlipressin and desmopressin are approved analogues. |
| GnRH | Endogenous | Natural | Reproductive axis | Approved (analogues) | GnRH agonist/antagonist medicines treat hormone-sensitive cancers and endometriosis. |
| TRH | Endogenous | Natural | Thyroid axis | Clinical evidence | Diagnostic and research use; not a chronic therapy. |
| CRH | Endogenous | Natural | Stress axis | Clinical evidence | HPA-axis driver; targets in stress and depression research. |
| ACTH | Endogenous | Natural | Cortisol release | Approved (analogue) | Synthetic cosyntropin/tetracosactide is used clinically. |
| MSH | Endogenous | Natural | Pigmentation · appetite | Approved (analogue) | Setmelanotide is an approved MC4R agonist for specific genetic obesity. |
| Somatostatin | Endogenous | Natural | Inhibits GH, insulin, glucagon, gut hormones | Approved (analogues) | Octreotide, lanreotide, pasireotide are approved analogues. |
| Gastrin | Endogenous | Natural | Gastric acid release | Clinical evidence | Endogenous GI peptide. |
| Secretin | Endogenous | Natural | Pancreatic bicarbonate release | Approved | Used diagnostically. |
| CCK | Endogenous | Natural | Gallbladder · satiety | Clinical evidence | Endogenous gut peptide (cholecystokinin). |
| VIP | Endogenous | Natural | Vasodilation · GI | Clinical evidence | Endogenous peptide; research targets. |
| Substance P | Endogenous | Natural | Pain transmission | Clinical evidence | Receptor targeted by NK1 antagonists in nausea. |
| Neuropeptide Y | Endogenous | Natural | Appetite · stress | Clinical evidence | Major brain neuropeptide. |
| CGRP | Endogenous | Natural | Vasodilation · migraine | Approved (pathway) | Anti-CGRP antibodies and gepants treat migraine. |
| Enkephalins | Endogenous | Natural | Endogenous opioid | Clinical evidence | Endogenous opioid peptides. |
| Endorphins | Endogenous | Natural | Endogenous opioid | Clinical evidence | Endogenous reward/analgesia peptides. |
| Dynorphins | Endogenous | Natural | Kappa opioid agonists | Clinical evidence | Endogenous kappa opioid peptides. |
| Angiotensin II | Endogenous | Natural | Vasoconstriction · BP | Approved (pathway) | Target of ACE inhibitors and ARBs. |
| Bradykinin | Endogenous | Natural | Vasodilation · inflammation | Clinical evidence | Involved in inflammatory responses. |
| Endothelin | Endogenous | Natural | Potent vasoconstriction | Approved (pathway) | Endothelin receptor antagonists treat pulmonary hypertension. |
| ANP | Endogenous | Natural | Natriuresis · vasodilation | Clinical evidence | Atrial natriuretic peptide; cardiovascular biomarker. |
| BNP | Endogenous | Natural | Heart-failure marker | Clinical evidence | Key diagnostic biomarker; nesiritide was an analogue medicine. |
| Kisspeptin | Endogenous | Natural | Reproductive axis trigger | Early clinical | Research and emerging fertility applications. |
| Defensins | Endogenous | Natural | Innate antimicrobial defence | Clinical evidence | Part of innate immunity; researched for novel antibiotics. |
| Cathelicidin LL-37 | Endogenous | Natural | Innate antimicrobial | Clinical evidence | Human cathelicidin; broad antimicrobial activity. Online injectable forms are unapproved. |
| Insulin analogues | Approved | Recombinant / modified | Diabetes | Approved | Recombinant insulins (lispro, glargine, detemir, aspart, degludec, etc.). |
| Semaglutide | Approved | Synthetic / modified | Type 2 diabetes · obesity | Approved | GLP-1 receptor agonist. |
| Tirzepatide | Approved | Synthetic / modified | Type 2 diabetes · obesity | Approved | Dual GIP/GLP-1 receptor agonist. |
| Liraglutide | Approved | Synthetic / modified | Diabetes · obesity | Approved | GLP-1 receptor agonist. |
| Exenatide | Approved | Synthetic / modified | Diabetes | Approved | GLP-1 receptor agonist (Gila monster lineage). |
| Desmopressin | Approved | Synthetic / modified | Diabetes insipidus · nocturia | Approved | Vasopressin analogue. |
| Terlipressin | Approved | Synthetic / modified | Hepatorenal syndrome · variceal bleed | Approved | Vasopressin analogue. |
| Octreotide | Approved | Synthetic / modified | Acromegaly · neuroendocrine tumours | Approved | Long-acting somatostatin analogue. |
| Lanreotide | Approved | Synthetic / modified | Acromegaly · NETs | Approved | Somatostatin analogue. |
| Pasireotide | Approved | Synthetic / modified | Cushing’s · acromegaly | Approved | Multi-receptor somatostatin analogue. |
| Leuprolide | Approved | Synthetic / modified | Hormone-sensitive cancers | Approved | GnRH agonist. |
| Goserelin | Approved | Synthetic / modified | Prostate · breast cancer | Approved | GnRH agonist depot. |
| Triptorelin | Approved | Synthetic / modified | Hormone-sensitive cancers | Approved | GnRH agonist. |
| Degarelix | Approved | Synthetic / modified | Prostate cancer | Approved | GnRH antagonist. |
| Relugolix | Approved | Synthetic small molecule | Prostate · endometriosis · fibroids | Approved | Oral GnRH antagonist; non-peptide acting on the same pathway. |
| Teriparatide | Approved | Recombinant | Osteoporosis | Approved | Recombinant PTH(1–34) fragment. |
| Abaloparatide | Approved | Synthetic / modified | Osteoporosis | Approved | PTHrP analogue. |
| Calcitonin | Approved | Recombinant / natural | Bone · Paget’s disease | Approved | Salmon calcitonin in clinical use. |
| Teduglutide | Approved | Recombinant / modified | Short bowel syndrome | Approved | GLP-2 analogue. |
| Linaclotide | Approved | Synthetic / modified | IBS-C · chronic constipation | Approved | Guanylate cyclase-C agonist peptide. |
| Plecanatide | Approved | Synthetic / modified | IBS-C · chronic constipation | Approved | Guanylate cyclase-C agonist peptide. |
| Bivalirudin | Approved | Synthetic / modified | Anticoagulation in PCI | Approved | Direct thrombin inhibitor, hirudin-derived. |
| Eptifibatide | Approved | Synthetic / modified | Antiplatelet | Approved | GPIIb/IIIa inhibitor. |
| Enfuvirtide | Approved | Synthetic | HIV fusion inhibitor | Approved | 36-amino-acid peptide; binds HIV gp41. |
| Ziconotide | Approved | Synthetic (cone snail-derived) | Severe chronic pain | Approved | N-type Ca²+ channel blocker; intrathecal administration. |
| Bremelanotide | Approved | Synthetic | Hypoactive sexual desire disorder (premenopausal women) | Approved (indication-specific) | An approved indication-specific medicine exists. Online grey-market “PT-141” products are different and risky. |
| Setmelanotide | Approved | Synthetic | Genetic obesity | Approved | MC4R agonist for specific genetic obesity syndromes. |
| Tesamorelin | Approved | Synthetic / modified | HIV-associated lipodystrophy | Approved | GHRH analogue approved for a specific indication. Not a generic “GH booster” in healthy adults. |
| BPC-157 | Grey-market | Synthetic | Promoted online for “injury recovery”, gut health, inflammation | Banned in sport · grey | Not listed on the ARTG; not approved for human use; WADA-prohibited under S0; Sport Integrity Australia reports no studies in human subjects. Avoid unsupervised use. |
| TB-500 | Grey-market | Synthetic | Promoted online for tissue repair | Banned in sport · grey | Related to thymosin beta-4. Not approved for human use; WADA-prohibited. Human evidence limited. |
| Thymosin beta-4 | Grey-market | Endogenous | Endogenous; researched in tissue repair | Preclinical | Endogenous peptide; experimental status varies. Online forms unapproved. |
| GHK-Cu (injectable) | Grey-market | Synthetic copper peptide | Promoted online for “healing”, skin, hair | Grey-market | Topical cosmetic GHK-Cu is a different thing. TGA flags unapproved injectable peptide products. Regulatory status varies. |
| CJC-1295 | Grey-market | Synthetic / modified | Promoted online for GH release | Banned in sport · grey | GHRH analogue. Not approved for human use; WADA-prohibited. Avoid unsupervised use. |
| Ipamorelin | Grey-market | Synthetic | Promoted online for GH release | Banned in sport · grey | GHRP class. Not approved for human use; WADA-prohibited. |
| GHRP-2 | Grey-market | Synthetic | Promoted online for GH release | Banned in sport · grey | Not approved for human use; WADA-prohibited. |
| GHRP-6 | Grey-market | Synthetic | Promoted online for GH release | Banned in sport · grey | Not approved for human use; WADA-prohibited. |
| Hexarelin | Grey-market | Synthetic | Promoted online for GH release | Banned in sport · grey | Not approved for human use; WADA-prohibited. |
| Sermorelin | Grey-market | Synthetic GHRH(1–29) | GHRH analogue | Early evidence | Regulatory status varies by jurisdiction and over time. Online forms are grey-market and WADA-relevant. |
| AOD-9604 | Grey-market | Synthetic GH fragment | Promoted online for fat loss | Early evidence | Not approved for human use. Trials in obesity were not convincing. |
| MOTS-c | Grey-market | Mitochondrial-derived peptide | Researched in metabolism | Preclinical | Human evidence limited. |
| Epitalon | Grey-market | Synthetic tetrapeptide | Promoted online for longevity | Preclinical | Claims rest on small, low-quality studies. Not approved. |
| Thymalin | Grey-market | Synthetic | Immune modulation | Early evidence | Experimental immunomodulator; regulatory status varies. |
| DSIP / emideltide | Grey-market | Synthetic / endogenous | Researched for sleep | Preclinical | Human evidence very limited. |
| Selank | Grey-market | Synthetic | Anxiolytic-like effects (research) | Early evidence | Researched in Russia; not approved internationally. |
| Semax | Grey-market | Synthetic | Researched for cognition | Early evidence | Researched in Russia; not approved internationally. |
| KPV | Grey-market | Synthetic MSH fragment | Anti-inflammatory (research) | Preclinical | Researched for inflammation. Human evidence limited. |
| LL-37 (injectable) | Grey-market | Synthetic / cathelicidin fragment | Promoted online for antimicrobial / inflammation | Grey-market | Endogenous antimicrobial peptide; injectable forms sold online are unapproved. |
| Melanotan II | Grey-market | Synthetic | Promoted online for tanning, libido | Grey-market | Not approved. Safety concerns documented in case reports. |
Evidence maturity system
“Peptide” does not mean safe, effective, or legal.
This page uses a consistent set of badges so the evidence behind each peptide is visible at a glance. Most controversy in the field comes from collapsing these categories into a single “peptide” label.
Regulator-approved prescription medicine with clinical trials, dosing studies, and manufacturing controls.
Multiple controlled human studies; may or may not be approved as a medicine.
Early-phase trials or small studies; conclusions tentative.
Cell and animal evidence; no robust human data.
Plausible mechanism; minimal direct evidence.
Promoted online; not approved for human use; safety, quality and identity not assured.
Listed by the World Anti-Doping Agency. Anti-doping risk for any athlete subject to testing.
Topical-skincare context; not equivalent to systemic injection.
Case study
BPC-157: the clearest example of peptide hype vs evidence.
Also known as Body Protective Compound 157, Bepecin, PLD-116, PL-10, PL14736, and informally the “Wolverine drug”. It is an experimental synthetic peptide widely marketed online for injury recovery, gut health, inflammation, and “healing”. The Australian regulatory and sports-integrity picture is unambiguous.
Approved peptide medicines
Peptide medicines are real, regulated, and clinically important.
These are not biohacker peptides. Approved peptide medicines go through clinical trials, dosing studies, pharmacokinetics, safety monitoring, regulated manufacturing, and prescription controls. Grouped by area:
Diabetes & obesity
Insulin analogues, GLP-1 receptor agonists, and dual incretin agonists.
Endocrine & reproductive
GnRH agonists/antagonists, oxytocin, vasopressin analogues, somatostatin analogues, ACTH analogues.
Gastrointestinal
Gut peptides used in chronic constipation, IBS, and short bowel syndrome.
Bone
PTH and PTHrP analogues, calcitonin.
Cardiovascular & anticoagulation
Thrombin inhibitors, antiplatelets, and pathway-related drugs.
Pain & neurology
Peptide and peptide-pathway drugs used in severe pain and migraine.
Infectious disease
Peptide fusion inhibitors used in HIV.
Drug-development reality
Why peptide drugs are hard.
Peptides have unique strengths — receptor selectivity, often low toxicity, biological precedent — but turning a sequence into a medicine runs into well-known engineering and biology problems.
Rapid degradation
Many peptides are quickly cleaved by enzymes in the gut and bloodstream.
Short half-life
Without modification, plasma half-life is often minutes to a few hours.
Poor oral bioavailability
Most peptides are destroyed in the gut and absorb poorly across mucosa.
Injection or special delivery
Many peptides require subcutaneous, intramuscular, or intrathecal administration.
Immunogenicity risk
Repeated dosing can provoke neutralising or anti-drug antibodies.
Manufacturing purity
Solid-phase synthesis produces close-sequence impurities that must be controlled.
Cold-chain & storage
Many peptide drugs need refrigerated storage and careful reconstitution.
Receptor selectivity
Off-target binding can produce significant unwanted effects.
Aggregation
Peptides can form aggregates that change activity and increase immunogenicity.
Peptide engineering
How chemists make peptides act like drugs.
Almost every approved peptide medicine uses one or more of these modifications. The point is improved stability, half-life, delivery, binding, and tissue targeting.
Cyclisation
Joining the peptide’s ends to lock a shape and resist enzymatic cleavage.
Stapling
Hydrocarbon bridges that lock an alpha-helix into the conformation that binds the target.
D-amino acids
Mirror-image residues that proteases struggle to cut.
N-methylation
Methyl groups on the backbone that disrupt protease recognition and improve membrane crossing.
Lipidation
Fatty-acid attachment that binds albumin and extends half-life dramatically (e.g., semaglutide).
PEGylation
Polyethylene-glycol chains that increase hydrodynamic size and reduce renal clearance.
Peptide-drug conjugates
A peptide targeting moiety linked to a small-molecule or radioactive payload.
Cell-penetrating peptides
Carrier sequences that ferry cargo across cell membranes.
Radiolabelled peptides
Receptor-targeting peptides carrying diagnostic or therapeutic radionuclides.
AI-designed peptides
In-silico structural design and language models proposing novel binders and antimicrobials.
Antimicrobial peptides
A different kind of antibiotic.
Antimicrobial peptides (AMPs) are part of the innate immune system across animals, plants, and bacteria. The Antimicrobial Peptide Database (APD6) reported 5,188 AMP records as of March 2025. AMPs disrupt microbial membranes and have several mechanisms beyond conventional antibiotics, which interests researchers as resistance to small-molecule antibiotics grows.
Defensins
Major innate-immunity AMPs in vertebrates and plants.
Cathelicidin LL-37
Human cathelicidin with broad antimicrobial and immunomodulatory activity.
Magainins
Frog-skin AMPs that became a model system for AMP drug discovery.
Nisin
Bacterial lantibiotic used as a food preservative.
Polymyxins
Cyclic lipopeptides used as last-line antibiotics for Gram-negative infections; nephrotoxic.
Daptomycin
Approved cyclic lipopeptide antibiotic for serious Gram-positive infections.
Cosmetic peptides
Topical, not injectable.
Cosmetic peptides are short sequences added to creams, serums, and lotions. They are not the same as injectable peptides, even when the name overlaps. Cosmetic claims are loosely regulated relative to therapeutic ones; evidence varies widely by ingredient and formulation.
GHK-Cu (topical)
A copper peptide used in skincare for collagen support claims. Injectable forms are unapproved.
Palmitoyl pentapeptides
Lipidated peptides marketed for skin texture; effects are modest.
Acetyl hexapeptide-8 / Argireline
Marketed for wrinkle reduction; mechanism likened to a topical neuromodulator.
Signal peptides
Sequences claimed to trigger collagen synthesis.
Carrier peptides
Help deliver trace elements (e.g., copper) into the skin.
Enzyme-inhibiting peptides
Block enzymes that break down skin proteins.
Regulatory and sports caution
What the regulators and anti-doping bodies actually say.
Source databases
Where peptide knowledge actually lives.
Any serious peptide question is best answered by going to a primary database rather than a marketing page. These are the references behind this page.
Human PeptideAtlas
Curated proteomics-derived catalogue of human peptides detected by mass spectrometry across hundreds of studies. The 2026 build reports 5,309,343 distinct peptides.
Best for understanding the scale and diversity of the human peptidome.
UniProt
Universal protein-sequence and functional-annotation database. Covers human and non-human peptides and proteins; the canonical reference for sequence-level information.
Best for sequences, function, post-translational modifications, and cross-references.
APD / APD6
Antimicrobial Peptide Database (APD6) — curated AMP records with sequence, source organism, activity spectrum, and structure where known. 5,188 AMP records reported as of March 2025.
Best for antimicrobial peptide research and discovery.
DBAASP
Database of Antimicrobial Activity and Structure of Peptides. Detailed activity, structure, and resistance information for thousands of AMPs.
Best for activity profiles and structure-activity relationships.
NeuroPep 2.0
Curated database of neuropeptides across species. Covers sequences, functions, receptors, and cross-references.
Best for neuropeptide research and target discovery.
THPdb2
A curated database of FDA-approved and clinical-stage therapeutic peptides. Tracks development status, indication, and structural data.
Best for mapping the therapeutic-peptide pipeline and approved drugs.
IUPHAR Guide to Pharmacology
Pharmacology database covering receptors, ion channels, ligands, and approved drugs — including peptide ligands and analogues.
Best for receptor pharmacology and ligand selectivity.
WADA Prohibited List
The World Anti-Doping Agency’s annual list of prohibited substances and methods, including peptide hormones, growth factors, and related substances.
Best for anti-doping status of specific peptides for tested athletes.
TGA safety alerts
Therapeutic Goods Administration alerts on unapproved peptide products, counterfeit and substandard medicines, and emerging safety signals.
Best for the Australian regulatory view on a specific peptide.
Frequently asked questions
Short, honest answers to common peptide questions.
Are peptides natural?
Many peptides are natural — they are made in our bodies as hormones, neurotransmitters, and immune molecules. But the word “peptide” also covers fully synthetic molecules, modified analogues, and laboratory designs. “Natural” does not automatically mean safe; many natural peptides are toxic if used out of context.
Are peptides safe?
It depends entirely on which peptide and how it is used. Approved peptide medicines have known safety profiles. Unapproved peptide products sold online may not be evaluated for safety, quality, or effectiveness, and the actual content of a vial is often not what the label claims.
Are peptides legal in Australia?
Approved peptide medicines are prescription-only. Many peptides promoted online are not approved by the TGA for human use; importing and possessing unapproved peptide products can carry legal and customs risks. This page does not give legal advice; check current TGA guidance and a qualified professional for your situation.
Is BPC-157 proven?
No. BPC-157 is not listed on the ARTG, is not approved for human use, is banned by WADA under S0, and per Sport Integrity Australia has no studies in human subjects. Existing evidence is preclinical. Short-term and long-term safety are unknown.
Why are some peptides approved while others are risky?
Approved peptide medicines have completed clinical trials, dosing studies, safety monitoring, and regulated manufacturing. Many marketed peptides have not. The label “peptide” tells you almost nothing on its own; the evidence behind the specific molecule is what matters.
Are topical peptides the same as injectable peptides?
No. Topical cosmetic peptides target the skin surface and produce limited, mostly modest effects. Injectable peptides enter systemic circulation and act through receptors throughout the body. The same name (e.g. GHK-Cu) can refer to very different products in those two contexts.
Why do peptide drugs often require injections?
Most peptides are digested in the stomach and absorbed poorly across the gut. They also have short half-lives. Injection bypasses these problems, and modifications like lipidation or PEGylation extend the half-life enough for practical dosing schedules.
Can peptides be oral?
Sometimes. Oral semaglutide is an example, made possible by special absorption enhancers. Oral peptide delivery remains a hard research problem in general; most peptide drugs still need injection.
Are peptides banned in sport?
Many are. WADA prohibits peptide hormones, growth factors, related substances, mimetics, GH fragments, GHRH analogues, GH secretagogues, GHRPs, IGF-1 analogues, TB-500, and BPC-157, among others. Athletes subject to testing should treat any unapproved peptide as an anti-doping risk.
What is the difference between peptide, protein, hormone, and biologic?
Peptide: a short chain of amino acids (roughly 2–50). Protein: a longer folded chain. Hormone: a signalling molecule released by one tissue to act on another — can be a peptide, a steroid, an amine, or other. Biologic: a regulatory category for medicines made by or from living systems, including recombinant peptides, proteins, antibodies, vaccines, and cell therapies.
What is a cyclic peptide?
A peptide whose ends are joined — head-to-tail, or via a side-chain bridge — locking the molecule into a defined shape. Cyclisation often improves stability against enzymes and enables binding to targets that small linear peptides cannot. Cyclosporine and octreotide are well-known cyclic peptide drugs.
What is a peptide-drug conjugate?
A peptide that binds a specific receptor, chemically linked to a small-molecule drug or radioactive payload. The peptide acts as a homing device delivering the payload to a target tissue. Octreotide-linked radiopharmaceuticals for neuroendocrine cancer are a clinical example.
Why is the grey market dangerous?
Because what is in the vial is often not what is on the label. Imported peptide products sold online have been reported to be poorly labelled, supplied as powders or injectables in unmarked vials, and missing active ingredient, concentration, or dosage information. Contamination, infection, tissue damage, allergic reactions, and inflammatory responses are documented risks. There is no quality control you can rely on.
Glossary
The vocabulary that makes peptide reading much easier.
The building block of peptides and proteins. About 20 standard amino acids are found in most life.
The amide bond formed between the amine of one amino acid and the carboxyl of another.
A short peptide, typically 2–20 amino acids.
A longer chain of amino acids; the line between long peptide and small protein is fuzzy.
A folded macromolecule made of one or more polypeptide chains, with structural and functional roles.
A protein on or in cells that detects a signal (like a peptide) and triggers a response.
A molecule that activates a receptor.
A molecule that binds a receptor without activating it, blocking the natural ligand.
The time it takes for the body to eliminate half of a drug.
The fraction of an administered dose that reaches the systemic circulation in active form.
The capacity of a drug to provoke an immune response, including anti-drug antibodies.
How the body affects a drug: absorption, distribution, metabolism, excretion.
How a drug affects the body: receptor binding, downstream effects, time course.
Joining the ends of a peptide to lock its shape and improve stability.
Attaching a fatty acid that lets the peptide bind albumin in plasma and extend half-life.
Covalent attachment of polyethylene glycol, increasing hydrodynamic size and reducing renal clearance.
Closely related peptide species produced during synthesis that must be controlled.
Australian Register of Therapeutic Goods — the official list of approved medicines in Australia.
Therapeutic Goods Administration — Australia’s medicines regulator.
World Anti-Doping Agency — maintains the Prohibited List for sport.
Products sold legally as “research chemicals” or imported without regulatory approval for human use, with no assurance of identity, purity, or safety.
Research sources
Where this page draws from.
Primary sources and reviews
- Human PeptideAtlas (2026 build)
- UniProt
- Therapeutic Peptides: Recent Advances in Discovery, Synthesis, and Clinical Translation
- Therapeutic peptides: current applications and future directions
- Advance in peptide-based drug development: delivery platforms, therapeutics, and vaccines
- THPdb2 — therapeutic-peptide database
- TGA — safety alerts on unapproved peptide products
- Sport Integrity Australia — BPC-157 information
- WADA Prohibited List
- APD6 antimicrobial peptide database
- DBAASP
- NeuroPep 2.0
- IUPHAR Guide to Pharmacology
Peptides are a real and important class of medicines and biology. They are also a magnet for hype, grey-market marketing, and unsafe products. This page exists to map the field clearly — categories, mechanisms, evidence levels, regulators, and source databases. It does not tell you how to use, inject, buy, cycle, or stack peptides. If you are considering any peptide for any reason, the right step is to talk to a qualified clinician — not a forum, not an influencer, and not an online vendor. In Australia, the TGA, ARTG, and Sport Integrity Australia are the bodies whose guidance carries weight.