Research library
Reference pages covering mechanism, the published literature, and laboratory handling for compounds in our catalog. Each includes an explicit assessment of evidence quality — including where the evidence is weak, single-sourced, or contested.
BPC-157: Mechanism, Literature, and Handling
BPC-157 is a synthetic pentadecapeptide corresponding to residues 1-15 of body protection compound, a protein isolated from human gastric juice. It is among the most widely discussed and least rigorously replicated peptides in the repair literature — a combination that makes an honest reference page unusually valuable.
4 sections · updated 2026-07-19
Semaglutide: Structure, Incretin Pharmacology, and Handling
Semaglutide is a GLP-1 receptor agonist whose design is a clean case study in solving the two problems that limit native incretin peptides: enzymatic degradation and renal clearance. Understanding what was changed and why explains most of its pharmacology.
4 sections · updated 2026-07-19
Tirzepatide: Dual Incretin Agonism and Structural Basis
Tirzepatide is a 39-amino-acid synthetic peptide that engages both the GIP and GLP-1 receptors from a single molecule. Its most frequently misunderstood property is that it is not a balanced dual agonist.
4 sections · updated 2026-07-19
Retatrutide: Triple Receptor Agonism and Glucagon Pathway Research
Retatrutide adds glucagon receptor agonism to the incretin pairing found in tirzepatide. That third receptor is the entire scientific interest of the molecule, and it is also the reason it remains investigational.
3 sections · updated 2026-07-19
TB-500 and Thymosin Beta-4: Actin Sequestration and Fragment Confusion
TB-500 is sold under a name that does not correspond to a single defined molecule. Resolving that ambiguity is the most practically important thing a researcher can know about it.
3 sections · updated 2026-07-19
GHK-Cu: Copper Coordination, Matrix Remodeling, and Gene Expression
GHK-Cu is one of the few peptides in this catalog that occurs endogenously in human plasma and has a genuinely well-characterized coordination chemistry. Its declining plasma concentration with age is the observation that started the field.
3 sections · updated 2026-07-19
5-Amino-1MQ: NNMT Inhibition and the State of a Very Thin Literature
5-Amino-1MQ (5-amino-1-methylquinolinium) is a small-molecule inhibitor of nicotinamide N-methyltransferase (NNMT). It is not a peptide, and it is the compound in this catalogue with the thinnest direct evidence base by a wide margin. A PubMed search for the compound and its full chemical name returns three indexed results in total. That number is the most important fact on this page.
3 sections · updated 2026-09-13
AOD-9604: The hGH 176-191 Fragment and a Literature Dominated by Detection
AOD-9604 is a synthetic analogue of the C-terminal region of human growth hormone, residues 176-191. It was developed on the hypothesis that the lipolytic activity of hGH could be separated from its growth-promoting and glucose-affecting activity. The literature is small, about eighteen indexed results, and the majority of it is anti-doping analytical chemistry rather than efficacy work.
3 sections · updated 2026-09-13
Cagrilintide: Long-Acting Amylin Analogue Pharmacology
Cagrilintide, developed as AM833, is a long-acting amylin analogue. Amylin is co-secreted with insulin by pancreatic beta cells and acts on receptors formed by the calcitonin receptor in complex with receptor activity-modifying proteins. Cagrilintide is one of the better-evidenced compounds in this catalogue: the literature includes randomised phase 2 and phase 3 trials published in the Lancet and the New England Journal of Medicine.
3 sections · updated 2026-09-13
CJC-1295 (no DAC): GHRH Analogue Pharmacology and a Naming Problem
CJC-1295 without DAC, also circulated as Mod GRF 1-29, is a modified fragment of growth hormone-releasing hormone. Before anything else about this compound is useful, one distinction has to be made clearly, because the literature and the common naming disagree: the compound described in the foundational CJC-1295 paper is the DAC version, and the no-DAC version is a pharmacologically different molecule with a different duration of action.
3 sections · updated 2026-09-13
DSIP: Delta Sleep-Inducing Peptide and an Unresolved Forty-Year Literature
DSIP is a nonapeptide first isolated from rabbit cerebral venous blood during sleep induction experiments in the 1970s. Its literature is unusual in this catalogue: reasonably large, largely concentrated in the 1980s, and explicitly unresolved. A 2006 review in the Journal of Neurochemistry is titled "a still unresolved riddle," which is a fair summary of the position two decades later.
3 sections · updated 2026-09-13
Epitalon: AEDG Tetrapeptide, Telomerase Claims, and Narrow Provenance
Epitalon is a synthetic tetrapeptide, Ala-Glu-Asp-Gly, developed from a pineal extract preparation. Around seventy results are indexed. The single most important feature of this literature is not any individual finding but its provenance: a large share of it originates from one research group, and that concentration should govern how the rest is weighted.
3 sections · updated 2026-09-13
Glutathione: Redox Biology and the Exogenous Delivery Problem
Glutathione is a tripeptide, gamma-Glu-Cys-Gly, and the principal intracellular thiol antioxidant in most cell types. Its literature is the largest in this catalogue by two orders of magnitude, with over two hundred thousand indexed results. That volume is misleading in a specific and important way: almost all of it concerns endogenous glutathione biology, and very little concerns administering glutathione from outside the cell.
3 sections · updated 2026-09-13
IGF-1 LR3: Binding Protein Evasion and a Sixteen-Paper Literature
IGF-1 LR3, or Long R3 IGF-1, is an analogue of insulin-like growth factor 1 carrying an arginine substitution at position 3 and a thirteen-residue N-terminal extension. Sixteen indexed results exist for the analogue specifically. That is one of the smallest literatures in this catalogue, and it is dominated by a single model system.
3 sections · updated 2026-09-13
Ipamorelin: Selective Growth Hormone Secretagogue Pharmacology
Ipamorelin is a pentapeptide growth hormone secretagogue acting at the ghrelin receptor, GHS-R1a. Around fifty results are indexed, and the compound's significance rests on a specific and well-defined claim made in 1998: that it was the first secretagogue in its class to release growth hormone without the accompanying hormone release seen with earlier compounds.
3 sections · updated 2026-09-13
Kisspeptin-10: KISS1R Signalling and the Desensitisation Problem
Kisspeptin-10 is the decapeptide C-terminal fragment of kisspeptin, the product of the KISS1 gene. It acts at KISS1R, formerly GPR54. Around four hundred and ten results are indexed. The receptor's role at the top of the reproductive axis is established well enough to be textbook material, which makes one experimental detail in the literature unusually important: what happens under continuous rather than pulsatile exposure.
3 sections · updated 2026-09-13
KPV: The alpha-MSH C-Terminal Tripeptide and PepT1 Transport
KPV is the tripeptide Lys-Pro-Val, corresponding to the C-terminal residues 11-13 of alpha-melanocyte stimulating hormone. Around eighty results are indexed. Its interest lies in a specific claim: that the tripeptide retains the anti-inflammatory activity of the parent hormone while lacking the melanocortin receptor engagement responsible for pigmentation.
3 sections · updated 2026-09-13
MOTS-c: Mitochondrial-Derived Peptide Signalling to the Nucleus
MOTS-c is a sixteen-residue peptide encoded in an open reading frame within the mitochondrial 12S rRNA gene. Around three hundred results are indexed. It belongs to a genuinely distinct class: peptides encoded by the mitochondrial genome rather than the nuclear one, which is why the discovery papers appeared in Cell Metabolism rather than in a peptide journal.
3 sections · updated 2026-09-13
NAD+: Redox Cofactor, Signalling Substrate, and the Precursor Question
NAD+ is not a peptide. It is a dinucleotide cofactor present in every living cell, and its literature runs to over eighty-five thousand indexed results. Two facts shape how that literature should be read: NAD+ has two entirely different roles, and almost all of the interventional work uses precursors rather than NAD+ itself.
3 sections · updated 2026-09-13
PT-141: Melanocortin Receptor Agonism and a Regulatory Approval
PT-141, bremelanotide, is a cyclic heptapeptide melanocortin receptor agonist. Around one hundred and twenty results are indexed. It occupies an unusual position in this catalogue: it has a defined central mechanism, randomised phase 3 trials, a published safety programme, and regulatory approval, which is a combination almost nothing else here can claim.
3 sections · updated 2026-09-13
Selank: Tuftsin Analogue Pharmacology and Provenance
Selank is a synthetic heptapeptide built from tuftsin, an immunologically active tetrapeptide fragment of IgG heavy chain, extended with a proline-glycine-proline sequence to slow degradation. Around one hundred and forty results are indexed. As with several compounds in this catalogue, the dominant feature of the literature is where it comes from: a large share originates from Russian research institutions and appears in journals with limited international circulation.
3 sections · updated 2026-09-13
Semax: ACTH(4-10) Analogue and the Cerebral Ischaemia Literature
Semax is a synthetic heptapeptide, Met-Glu-His-Phe-Pro-Gly-Pro, derived from ACTH residues 4-10 with a C-terminal Pro-Gly-Pro extension. Around two hundred and eleven results are indexed. Its literature is notably coherent: a large share uses one model, rat focal cerebral ischaemia, with gene expression as the readout.
3 sections · updated 2026-09-13
SS-31: Cardiolipin Binding and the Elamipretide Clinical Programme
SS-31, developed as elamipretide and also designated MTP-131 and Bendavia, is a tetrapeptide that concentrates in the inner mitochondrial membrane. Around four hundred and sixty results are indexed. It is one of the few compounds in this catalogue with a completed randomised controlled trial in a defined patient population, which makes both its positive and negative results unusually informative.
3 sections · updated 2026-09-13
Tesamorelin: GHRH Analogue with an Approved Indication
Tesamorelin, developed as TH9507, is a stabilised analogue of human growth hormone-releasing hormone. Around one hundred and twenty-six results are indexed. Unlike most growth hormone secretagogues discussed in this catalogue, it has an approved indication supported by pooled phase 3 data, which makes it a useful benchmark for what adequate evidence in this class looks like.
3 sections · updated 2026-09-13
Thymosin Alpha-1: Immune Modulation and the Sepsis Trial Result
Thymosin alpha-1, marketed as thymalfasin, is a 28-residue acetylated peptide originally isolated from thymosin fraction 5 of calf thymus. Around eight hundred and sixty results are indexed, making it one of the better-studied compounds in this catalogue. It is approved in a number of countries for specific indications, and a large randomised trial reported in 2025.
3 sections · updated 2026-09-13