Glossary

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Affiliate links carry an Ad label directly at the link and additionally use the sponsored nofollow attribute. The label applies even to shop links without a confirmed partnership. Partner status and a possible commission do not change how a vendor is evaluated.

A molecule that binds a receptor and triggers its signalling chain. Opposite: antagonist.

An agonist binds to a receptor and activates the signalling chain linked to it, similar to a key unlocking a lock. The counterpart is an antagonist: it also binds the receptor but does not trigger a signalling chain, instead occupying the site and blocking an agonist from binding. Studies use both roles to probe receptor signalling pathways in a targeted way.

An aliquot is a small, measured portion taken from a larger laboratory solution, usually stored separately.

An aliquot is a separated sample portion. Separate portions can avoid repeated temperature cycling of the whole stock.

Also: Amino acids

The basic building block that peptides and proteins are assembled from via peptide bonds.

Amino acids contain an amino group and a carboxyl group. Proteins are commonly described using 20 standard amino acids. Peptide bonds join them into chains; their order is called the sequence.

Also: Analogues

A synthetically modified variant of an endogenous peptide with a slightly altered structure.

An analogue is a lab-made variant of a naturally occurring peptide in which individual amino acids have been swapped, added or removed. Researchers use such structural changes to study properties like stability or receptor binding behaviour in a targeted way. One example is semaglutide, an analogue of the endogenous hormone GLP-1.

A laboratory animal, such as a mouse or rat, used to study a substance in vivo. Not direct proof for humans.

An animal model is a laboratory animal such as a mouse, rat or zebrafish in which metabolism, behaviour or tissue is studied under controlled conditions. It serves preclinical research before a possible clinical trial. Because genetics and physiology differ, an effect in an animal model is not proof of an effect in humans.

Also: AMPs, Host defence peptides

Antimicrobial peptides are part of innate immune defence, produced in skin and mucous membranes.

Antimicrobial peptides, also called AMPs or host defence peptides, are part of innate immune defence. They are produced by skin and mucosal cells as well as immune cells and insert into the membranes of bacteria, fungi or viruses. The best-known human group is the cathelicidins, whose only active human form is LL-37. Beyond this direct membrane mechanism, AMPs are also studied as immune system signalling molecules.

Also: Anti-Obesity Drug 9604, Tyr-hGH Frag 177-191

Modified growth hormone fragment investigated in metabolic studies.

The cited original paper investigates AOD-9604 in Zucker rats. Findings from this animal model cannot be directly transferred to humans or products sold by research suppliers.

Also: Correlation, Causation

Two things occur together. That alone does not show that one causes the other.

An association means that two characteristics occur together statistically, such as a habit and a health outcome. Causation means that one produces the other. Observational studies usually show only associations, because confounders, reverse direction or chance can explain the link. Cause and effect needs additional evidence, such as randomised trials.

Also: BAC water

Bacteriostatic water is sterile water with a preservative, usually benzyl alcohol, for solutions used more than once.

Bacteriostatic means that bacterial growth is inhibited. Composition is product-specific; medicinal preparations can contain benzyl alcohol. This description verifies neither compatibility with a particular peptide nor the safety of a shop product.

Also: Batch, Lot

A batch is a single production run with its own batch number, the one a CoA actually refers to.

The batch number links one particular vial to the matching report, which is what makes a result traceable. A CoA with no clear batch reference cannot be tied to an actual product and says correspondingly little.

The proportion of a substance that reaches the bloodstream unchanged and can be measured there.

Bioavailability indicates what proportion of an administered substance ultimately reaches systemic circulation unchanged, measured as a percentage. It depends partly on how much the substance is broken down by enzymes, such as through proteolysis, on its way through the body. Pharmacokinetic studies determine bioavailability separately for different routes of administration.

Also: Peptide bioregulators, Khavinson peptides

Bioregulators are very short synthetic peptides of two to four amino acids studied at organ systems.

In parts of peptide research, this term describes short sequences investigated for involvement in gene regulation. It is not a regulatory category establishing efficacy. Individual cellular findings establish neither organ-specific benefits nor extension of human lifespan.

Blinded test: people involved do not know relevant details about the sample.

In a blinded laboratory test, information about a sample’s origin is withheld before analysis. This can reduce expectation bias but cannot rule out error or bias. Sampling, methods and documented traceability still matter. Peptide Compass does not conduct its own blinded tests.

Also: Body Protection Compound 157, PL 14736

Synthetic peptide investigated in preclinical models.

The linked cellular and animal study investigates blood-vessel formation and VEGFR2 signalling. Such preclinical findings do not establish efficacy or safe use in humans.

Also: AM833, NN9838

Synthetic amylin analogue investigated in metabolic research.

The cited development paper describes the structure and selection of a long-acting amylin analogue. An investigational medicine must be distinguished from a research chemical sold under the same name.

Also: Case Report

A detailed account of a single, often unusual case. Provides an early lead but no statistical evidence.

A case report describes observations in a single person or a small group of cases, often an unusual reaction or a rare event. It can prompt further research, but it has no control group and no statistical analysis. A case report alone does not prove a general effect.

A graphical record of chromatographic separation, for example in HPLC.

A chromatogram shows the detector signal during chromatographic separation. Peaks can overlap. Area percentages depend on the method and detector and are not automatically mass percentages. A chromatogram alone does not confirm peptide identity.

Also: CJC-1295 with DAC, DAC:GRF

Synthetic GHRH analogue investigated in endocrine research.

The linked paper investigates a long-acting GHRH analogue in healthy adults. The studied compound must be distinguished from differently modified forms offered under similar trade names.

Also: Clinical study

A study in human participants, usually structured in phases I to III. The most informative study type for humans.

A clinical study investigates a medical question involving people. Studies differ in size, comparison groups, blinding and outcomes measured. These features help determine how reliable a result is. Registration or publication of a study alone does not establish approval or the quality of a shop product.

Certificate of Analysis

Also: Certificate of analysis, Test report

A CoA is a report tied to a specific batch, listing batch number, test method and values such as purity or identity.

The value of a CoA depends on the batch number, since only that ties a report to one particular vial. A generic sample CoA with no link to a real batch says little about the actual product. Common entries include purity, identity and sometimes an endotoxin value.

Also: Cohort studies

An observational study that follows groups differing in one characteristic over time and compares an outcome.

In a cohort study, groups of people who differ in one characteristic (for example smoking or not smoking) are followed over a period of time and a particular outcome is compared. Researchers do not intervene. Such studies show associations, not cause and effect, because the groups may also differ in other ways.

Concentration states how much of a substance is dissolved in a given volume of liquid, usually in mg per ml.

Mass concentration relates the mass of a specified substance to the final solution volume, for example in mg/ml. Powder weight and actual peptide mass can differ. This value describes composition, not an application.

Also: CI, Confidence range

A range of values built to include the true value with a stated probability, usually 95%.

A confidence interval (CI) is a range of values built so that it includes the true value of a quantity, such as a rate or hazard ratio, with a stated probability, usually 95%. A narrow interval suggests a more precise estimate. If the interval of a hazard ratio includes 1, a difference between the groups is not statistically established.

Also: Confounding factor, Confounding variable

A factor linked to both the outcome and the studied characteristic that can distort or fake an association.

A confounder can cause or prevent the outcome of interest without being an intermediate step of the characteristic under study. It is also linked to that characteristic and can distort an association or create one. Example: coffee drinkers smoke more often on average, so a lung condition could wrongly be blamed on coffee. Studies account for confounders through random assignment or statistical adjustment.

Also: GHK-Cu complexes

Copper peptides are complexes of a small peptide and a copper ion, the best known being GHK-Cu.

Copper peptides are compounds in which a small peptide coordinates a copper ion. The best-known example is GHK, a three-amino-acid peptide found in human blood plasma, saliva and urine, where it naturally occurs bound to copper. In its copper-complex form, GHK-Cu is studied mainly in skin research, with additional preclinical data on connective tissue and wound healing.

A counter ion is a peptide's salt partner, usually trifluoroacetate (TFA) or acetate, left over from manufacturing.

A counterion balances electrical charge. Counterions can contribute to sample weight without being part of the peptide’s amino acid sequence.

Also: PNB-0408, N-Hexanoyl-Tyr-Ile-(6)aminohexanamide

Synthetic angiotensin IV analogue investigated in preclinical models.

Dihexa is investigated in animal models. The early paper with PMID 23055539 carries an Expression of Concern and is not treated here as secure evidence. The additional linked paper describes a rat model and does not establish human use.

The documentation score shows how many verified vendor claims are actually documented.

The methodology defines five weighted criteria. Currently, laboratory documentation, legal information and shipping contribute; price and range remain unscored. Missing criteria are omitted and the remaining weights are normalised. The score is not a quality seal or a product safety assessment.

Also: Double blinding, Double blind

A study design where neither participants nor staff know who gets the active substance or placebo. Reduces unconscious bias.

Participants and the blinded members of the study team do not know group assignments. This can reduce expectation and assessment bias. Blinding is a quality feature but does not rule out other methodological errors.

Also: Delta Sleep Inducing Peptide, Delta Sleep Peptide

Delta sleep-inducing peptide, originally described in animal experiments.

DSIP was isolated and experimentally investigated in an early rabbit study. Its name reflects the research hypothesis at that time. It does not establish a reliable sleep effect in humans.

European Medicines Agency

The EMA is the EU agency that coordinates and assesses centralised marketing authorisation procedures.

The European Medicines Agency coordinates scientific assessment in the centralised EU authorisation procedure and publishes assessment reports. The European Commission makes the authorisation decision. An EMA report is not a testing certificate for products sold by a research supplier.

Endotoxins are bacterial cell wall components, with the amount in a sample usually stated in units per milligram.

Bacterial endotoxins are components of Gram-negative bacteria. Results use endotoxin units with a stated reference quantity. Tests include conventional LAL methods and recombinant reagents. Endotoxin testing, sterility testing and chemical purity testing answer different questions.

Also: Epithalon, AEDG tetrapeptide

Synthetic tetrapeptide investigated in cell cultures for telomerase activity.

The cited paper investigates epithalon in human fibroblast cell cultures. Observations of telomerase in isolated cells do not establish extension of human lifespan.

Evidence coverage shows how many of the five score criteria are documented for a vendor.

Because missing criteria are omitted from the score calculation and the remaining weights redistributed, a single documented criterion alone can already produce a high value. Vendors with different evidence coverage are therefore only partly comparable. The number of documented criteria is shown next to the score.

Food and Drug Administration

US agency responsible for regulating medicines, food and medical devices, among other products.

The Food and Drug Administration regulates medicines, food and medical devices, among other products, in the United States. Not every regulated product category receives premarket approval. FDA approval concerns a specific product and is not EU authorisation.

A short section of a larger endogenous peptide or protein, synthetically reproduced.

A fragment covers only a section of the original amino acid chain of a peptide or protein, not the full sequence. Such partial sequences are synthesised to study which part of a chain is responsible for particular properties, such as receptor binding. One known example is thymosin alpha-1, a fragment of a larger precursor protein.

Also: Glycyl-L-histidyl-L-lysine copper, Copper tripeptide-1

Complex of the tripeptide GHK and copper investigated in various preclinical models.

GHK stands for glycyl-histidyl-lysine. The linked study investigates the copper complex in an experimental colitis model and cellular assays. It is not clinical evidence for skin care or other uses.

Growth hormone-releasing hormone

Also: Somatoliberin

GHRH is a hypothalamic hormone that triggers the pituitary gland to release growth hormone.

Growth hormone-releasing hormone is a hypothalamic peptide that travels via the pituitary portal system to the pituitary gland, where it triggers growth hormone release from somatotroph cells. It is part of the growth hormone axis and is the counterpart to the body's own inhibitor, somatostatin. Several synthetic GHRH analogues bind the same receptor and are studied or used in this context.

Growth hormone-releasing peptide

Also: GH secretagogues, Growth hormone secretagogues

GHRPs are synthetic peptides that trigger growth hormone release through the ghrelin receptor.

Growth hormone-releasing peptides are a class of synthetic peptides that bind the ghrelin receptor (GHS-R) to trigger growth hormone release from the pituitary gland. Unlike GHRH analogues, they use a separate signalling pathway and are often combined with GHRH analogues in research. The ghrelin receptor is also involved in regulating hunger and appetite.

Glucose-dependent insulinotropic polypeptide

GIP is a gut hormone that regulates insulin release after carbohydrate-rich meals.

Glucose-dependent insulinotropic polypeptide is the second major incretin hormone alongside GLP-1. K cells in the upper small intestine release it after eating, and it binds the GIP receptor to regulate insulin release. It is also involved in fat metabolism. Several newer diabetes and obesity compounds combine GIP with GLP-1 receptor agonism.

Glucagon-like peptide 1

Also: Glucagon-like peptide-1

GLP-1 is a gut hormone released after eating that regulates insulin release.

Glucagon-like peptide 1 is an incretin hormone released by L cells in the small intestine after eating. It binds the GLP-1 receptor, regulates insulin release, slows gastric emptying and is involved in satiety signalling in the brain. Several synthetic GLP-1 receptor agonists target this system, and some are approved as medicines.

Good Manufacturing Practice

GMP is a recognised quality standard for manufacturing medicinal products and similar goods.

Good Manufacturing Practice covers requirements for facilities, processes, documentation and traceability in production. GMP is mandatory mainly for authorised medicinal products. A manufacturer's GMP claim does not replace independent evidence such as a public CoA and applies only insofar as it is documented.

Somatotropin

Also: GH, HGH, Somatotropin

Growth hormone is a pituitary hormone that regulates growth, metabolism and body composition.

Growth hormone, also called somatotropin or GH, is produced by somatotroph cells in the pituitary gland and released into the blood in pulses, controlled by GHRH, somatostatin and ghrelin. It regulates longitudinal growth, muscle and fat metabolism and bone density, both directly and via IGF-1 from the liver. Several peptide classes target different points along this axis, including release from the anterior pituitary.

The time it takes for a substance's concentration in the body to drop by half.

Half-life describes how long it takes for a peptide's blood concentration to fall to half its starting value. It is measured in pharmacokinetic studies and varies considerably between individual peptides, partly depending on how quickly endogenous enzymes break down the chain through proteolysis. A shorter half-life means faster breakdown compared with a longer one.

Also: HR

A measure comparing how often an event occurs in two groups over time. A value of 1 means no difference.

The hazard ratio (HR) compares how often an event, such as disease progression, occurs in one group relative to another group over time. A value of 1 means no difference; values above or below 1 show which group had the event more often. It says nothing about absolute risk and is read together with a confidence interval.

Synthetic peptide investigated in studies of the growth hormone axis.

The cited original paper describes hexarelin as a synthetic peptide and investigates growth hormone release in rats. Such model findings do not establish safe human use.

High-performance liquid chromatography

Also: High-performance liquid chromatography

HPLC is the standard analytical method used to determine a peptide sample's purity as a percentage.

The method separates a sample into its components and measures each one, producing a chromatogram with one peak per component. The area of the main peak gives the stated purity value. HPLC alone says nothing about identity, that requires mass spectrometry as well.

Therapeutic Products Advertising Act

The HWG regulates advertising of medicinal products and therapeutic methods to the public in Germany.

The German Therapeutic Products Advertising Act restricts how medicinal products and treatment methods may be described publicly, including claims about disease or human use. This is why Peptide Compass describes substances only in terms of research findings and makes no statements about an effect in the reader's body.

Identity, confirmed by mass spectrometry, verifies that a sample actually contains the stated peptide.

It is usually shown via LC-MS, a combination of liquid chromatography and mass spectrometry that measures molecular weight. Purity and identity are two separate figures, and a complete CoA lists both. Purity alone does not prove which molecule is actually present.

Insulin-like growth factor 1

Also: Somatomedin C

IGF-1 is a hormone produced mostly in the liver in response to growth hormone.

Insulin-like growth factor 1 is produced mainly in the liver, triggered by growth hormone binding to liver cells, and circulates in the blood largely bound to carrier proteins. It binds the IGF-1 receptor and mediates much of growth hormone's effect on muscle, bone and connective tissue. An IGF-1 analogue with an extended half-life is used in research as a standalone tool, independent of the body's own regulation via growth hormone.

Also: Long R3 IGF-1, LR3-IGF-1, IGF-1 Long R3

Modified IGF-1 analogue investigated in preclinical models.

The cited paper investigates Long R3 IGF-I in guinea pigs and describes reduced affinity for IGF-binding proteins. Findings for this modified form are not interchangeable with findings for endogenous IGF-1.

Also: in vitro

A test outside a living organism, usually on cell cultures. It says nothing about an effect in humans.

In vitro studies examine isolated cells or molecules in a controlled setting such as a petri dish. They can show early biochemical effects, but the cell context does not replace a whole organism. This kind of data counts as lab research only and does not translate to humans.

Also: in vivo

An investigation in a living organism. The term alone does not distinguish animal from human data.

In vivo means that an investigation takes place in a living organism. This may be an animal or a human. Research findings must therefore identify the model studied. Animal results cannot be directly transferred to humans.

Also: Incretin hormones

Incretins are gut hormones released after eating that are involved in regulating insulin release.

Incretins are a hormone class from the gut that includes GLP-1 and GIP. They are released from specialised gut cells after eating and bind their own receptors on pancreatic beta cells. Through this mechanism, insulin release after oral glucose intake is higher than after an intravenous dose of the same amount, an effect known as the incretin effect. Several approved and investigational medicines mimic this pathway.

Also: NNC 26-0161

Synthetic pentapeptide investigated in studies of growth hormone release.

The development paper describes a pentapeptide and investigates receptor involvement and hormone release in cellular and animal models. Those findings cannot be generally transferred to humans.

ISO/IEC 17025

ISO 17025 is the international standard for the technical competence of testing and calibration laboratories.

Accreditation under this standard means a lab's procedures, equipment and staff were independently assessed. It is a quality marker for the laboratory itself, not a guarantee for any one specific CoA result.

International Unit

Also: IU

The International Unit measures a substance's biological potency against a reference standard, not its weight.

For substances such as growth hormone, weight alone does not describe the amount meaningfully, because different batches can vary in purity at the same weight. The International Unit instead sets the amount in relation to a defined WHO reference preparation. One milligram of one hormone therefore does not automatically equal the same number of units as one milligram of a different preparation.

Also: Metastin (45-54), KP-10

Peptide family investigated in endocrine research; this catalogue focuses on kisspeptin-10.

The cited study investigates kisspeptin-10 in men. Other isoforms such as kisspeptin-54 must be considered separately. The umbrella term kisspeptin does not fully specify the form studied.

Also: Lys-Pro-Val, alpha-MSH(11-13)

Melanocortin-derived tripeptide investigated in preclinical inflammation models.

KPV stands for lysine-proline-valine, a short fragment in the melanocortin context. The cited paper investigates it in mouse models of inflammatory bowel disease. This is not clinical evidence of use.

Light protection covers measures that shield a sample from light exposure, such as amber vials or storage in the dark.

Photostability tests investigate whether light changes a substance or formulation. Suitable packaging can limit exposure. Required conditions are product-specific; light protection alone does not establish a particular shelf life.

Also: Cathelicidin, hCAP18(134-170), Human Cathelicidin

Endogenous antimicrobial peptide also investigated in clinical wound research.

The linked randomised trial investigates LL-37 in hard-to-heal venous leg ulcers. Its findings concern the specific study preparation and design, not every product labelled LL-37.

Material obtained by freeze-drying, such as a powder in a laboratory vial.

Freeze-drying removes water from a frozen sample under vacuum. It leaves a dry powder or porous cake. Stability and shelf life depend on the substance, formulation and packaging; the physical form alone does not guarantee them.

Also: Marketing authorisation

Marketing authorisation is the regulatory approval required to sell a medicinal product in a market.

In the centralised EU procedure, EMA evaluates the scientific dossier. The European Commission grants marketing authorisation. Authorisation applies to a particular medicinal product under specified conditions, not to every product bearing the same substance name.

Also: MS

Mass spectrometry determines a sample's molecular weight and so confirms which molecule is actually present.

Combined with liquid chromatography (LC-MS), it verifies a peptide's identity independently of its purity value. A high purity value without this check says nothing about whether the correct molecule is present at all.

Also: Medicine

A medicinal product is legally defined as a substance intended to treat or prevent disease in humans.

Section 2 of Germany’s Medicines Act covers substances based on their intended disease-related use and certain pharmacological, immunological or metabolic functions. Classification is distinct from marketing authorisation. An RUO label does not automatically exclude medicinal-product status.

Also: Melanocortin system

Melanocortins are peptide hormones derived from POMC that bind five receptor types regulating skin, appetite and sexual response.

Melanocortins are a family of peptide hormones derived from the precursor protein proopiomelanocortin (POMC), including alpha-MSH and ACTH. They bind five distinct melanocortin receptors (MC1R to MC5R) that regulate skin pigmentation, appetite, energy balance, inflammatory processes and sexual response, among other functions. Synthetic melanocortin receptor agonists target individual receptors within this system.

Also: MT-2, MT2

Synthetic melanocortin analogue investigated in early clinical studies.

The cited early phase I paper investigates melanotan II in a small pilot study. It does not establish a reliable benefit-risk assessment for general use.

A statistical synthesis of multiple studies addressing a shared question.

A meta-analysis statistically combines comparable results from multiple studies. It can provide more precise estimates. Its strength depends on the quality, comparability and completeness of the included evidence.

One milligram equals 1000 micrograms, the standard mass unit for small peptide amounts on labels and CoAs.

Milligrams (mg) and micrograms (µg) are both subunits of the gram and differ by a factor of 1000. Vial labels and CoAs usually state the peptide amount in milligrams, while individual component figures sometimes appear in micrograms. The calculator on this page converts between grams, milligrams and micrograms on a purely mathematical basis.

Also: Mitochondrial peptides

Mitochondrial peptides target cellular energy production or originate from mitochondrial DNA.

Mitochondrial peptides are not a single substance class in the classical sense. The term groups together peptides that either bind at the inner mitochondrial membrane or are encoded by mitochondrial rather than nuclear DNA. The second group includes a short peptide derived from the mitochondrial 12S rRNA gene, studied in metabolic research. Another example binds cardiolipin in the inner membrane and is used in research on cellular ageing and energy metabolism.

Also: Mitochondrial-Derived Peptide MOTS-c, Mitochondrial Open Reading Frame of the 12S rRNA Type-c

Mitochondrial DNA-derived peptide investigated in preclinical metabolic models.

The discovery paper describes a short sequence encoded in mitochondrial DNA and investigates it in cellular and animal models. Its role in mitochondrial research does not establish a benefit of a marketed product.

Net peptide content states what share of a powder's mass is actually the peptide itself.

Peptide content is the actual peptide fraction of a sample. Water and other constituents can make powder mass differ from peptide mass.

A peptide that acts as a signalling molecule between cells in the nervous system.

Neuropeptides are peptides released by nerve cells that act as signalling molecules within the nervous system. They differ from classic neurotransmitters in their larger molecular structure and also bind to specific receptors on target cells. In research, neuropeptides are used among other things to map signalling pathways in the central nervous system.

Also: Smart Drugs

Nootropics are a broad substance class studied in relation to memory, learning or stress processing.

Coined by Giurgea in 1972, the term describes substances investigated in relation to cognitive functions. The label alone establishes neither benefit nor safety. Different substances and study designs require separate assessment.

Also: Observational studies

A study in which people are only observed or outcomes are measured, with no intervention such as a treatment.

In an observational study, people are observed or outcomes are measured without researchers trying to influence the result, for example through a treatment. Cohort studies are one example. Because groups are not assigned at random, observational studies can show associations but cannot prove a cause.

Di-, tri- and oligopeptide

Also: Dipeptide, Tripeptide

A short amino acid chain, classified by length as di-, tri- or oligopeptide.

Oligopeptides contain a small number of amino acids. Two form a dipeptide and three a tripeptide. The boundary with longer polypeptides is a naming convention, not a distinct change in molecular type.

Also: OXT, Pitocin

Endogenous peptide hormone also investigated in studies of social behaviour.

The linked behavioural study investigates decisions in an experimental trust game. Such findings establish neither generally improved social relationships nor the safety of freely marketed products.

A code associated with an affiliate programme, subject to the supplier’s terms.

A partner code is associated with an affiliate programme. Whether it generates a discount or commission depends on the applicable terms. Currently documented partnerships and codes are listed in our affiliate disclosure; they do not change the documentation score.

Expert review of a study manuscript by independent specialists before publication.

In peer review, independent experts check the methodology, data analysis and conclusions of a manuscript before publication. They can request corrections or reject the work. A peer-reviewed publication is considered more trustworthy than an unreviewed text, though it is no guarantee against error.

Also: PDA, BPC-157 arginate salt

Trade designation for a form marketed as an arginine salt of BPC-157.

The cited original study investigates BPC-157. It does not establish special properties of a salt form sold as pentadeca arginate. A reliable, dedicated source demonstrating superior solubility or stability of this marketed form has not been established here.

Also: Peptides

A short chain of amino acids linked by peptide bonds.

Two linked amino acids form a dipeptide; three form a tripeptide. Longer chains are also called polypeptides. A fixed boundary of 50 amino acids does not distinguish peptides from proteins in every field.

The chemical link that joins two amino acids into a chain.

A peptide bond forms when the carboxyl group of one amino acid reacts with the amino group of the next, releasing a water molecule in the process. This link repeats along the entire chain and forms the backbone of peptides and proteins. The order of the amino acids joined this way sets the sequence.

A hormone the body produces that is chemically an amino acid chain.

A peptide hormone is a signalling molecule built from a chain of amino acids, unlike steroid hormones, which are based on cholesterol. Peptide hormones are produced in glands or specialised cells and bind to receptors on target cells. Insulin is a well-known example of an endogenous peptide hormone.

Also: Inactive preparation

A dummy preparation with no active ingredient, used to compare against a real substance in a trial. Separates real from expected effects.

A placebo looks like the tested preparation but contains no active ingredient. In a study design it serves as the comparison group, showing how much of a response comes from participant expectation rather than the substance itself. Placebo control is a core feature of informative clinical trials, often combined with blinding.

Also: Preclinical research

The research stage before any human use: cell culture and animal model. Clinical trials follow only after this stage.

Preclinical research covers in vitro and in vivo experiments that check early effects and safety before a substance is ever tested in humans. It provides the data basis for a possible later clinical trial. A preclinical result alone does not support a claim about humans.

A study manuscript published before peer review. Results count as preliminary, not yet independently checked.

A preprint is published on an open platform before a journal has reviewed it. This speeds up the exchange of results but means the methodology and conclusions have not yet been independently checked. Content from a preprint should be judged more cautiously than a peer-reviewed publication.

A prescription requirement means a medicinal product may only be dispensed against a doctor's prescription.

In Germany, section 48 of the Medicines Act and the prescription medicines regulation are particularly relevant. Prescription requirements, medicinal-product status and authorisation are separate questions. Sale as a research chemical does not establish a blanket exemption.

Price per milligram makes offers with different pack sizes directly comparable.

The figure is the list price divided by the milligram content of a product, compared for the same active substance and currency. Shipping, availability and discount terms are included only when explicitly documented. A lower figure says nothing about purity or documentation.

Also: Protein

A molecule made of amino acid chains with diverse biological roles.

Proteins consist of one or more amino acid chains. Their sequence and spatial structure determine their properties. A fixed chain length alone does not define the distinction from peptides.

The enzymatic breakdown of an amino acid chain into smaller fragments.

Proteolysis is the process by which enzymes called proteases cleave the peptide bonds in an amino acid chain, breaking it into smaller fragments. This breakdown happens continuously in the body and affects how long a peptide stays intact, in other words its half-life. Studies often report proteolytic stability as a measure of a peptide's durability.

Also: Bremelanotide, Vyleesi

Bremelanotide, a synthetic melanocortin receptor agonist investigated in clinical trials.

PT-141 is another name for bremelanotide. The linked publication describes two randomised phase III trials in a defined patient population. A research product sold by a shop is not equivalent to the study preparation.

A free database run by the US National Library of Medicine for biomedical literature.

PubMed indexes millions of articles from medicine and life sciences and usually shows a free abstract directly. The full text often sits behind the respective journal's paywall. A PubMed listing confirms that a paper is indexed, but it says nothing about the quality of that individual study.

Purity states how much of a sample's chromatogram peak area belongs to the main molecule, usually as a percentage from HPLC.

Purity describes the proportion of the target substance within a stated method. An HPLC area percentage does not fully establish composition.

Randomised controlled trial

A study design with random assignment to a treatment and a control group. Considered the gold standard for proving an effect.

In a randomised controlled trial, participants are assigned by chance to a treatment or a control group, often blinded as well. This reduces bias from expectation or selection. RCTs are considered the methodological gold standard in clinical research, especially combined with placebo control.

A protein on or inside a cell that a peptide binds to specifically.

A receptor is a protein that specifically recognises and binds a matching molecule, such as a peptide, similar to a lock and key. This binding triggers a signalling chain inside the cell. In research, how strongly a peptide binds to a given receptor is called affinity and is often studied in the lab using cell cultures.

Reconstitution is dissolving a lyophilised peptide in a liquid to prepare a solution for laboratory use.

The term means restoring a liquid form from a dry preparation. The suitable liquid depends on the substance and analytical procedure. The term does not imply a general preparation or administration method.

Also: LY3437943

Peptide triple-receptor agonist investigated in clinical trials.

The linked phase II trial investigates an agonist at GIP, GLP-1 and glucagon receptors. Results from that trial do not establish equivalence of a shop product sold under the same name.

Research Use Only

Research Use Only describes a research purpose. The abbreviation alone does not establish a product’s legal status.

The label describes the supplier’s stated intended purpose. It is neither an authorisation nor evidence of purity or safety. Whether a product legally qualifies as a medicine depends on statutory criteria and its actual presentation, not solely on this abbreviation.

Synthetic peptide investigated in studies of anxiety disorders.

The linked clinical paper compares selank with medazepam in anxiety disorders and neurasthenia. A single publication replaces neither a comprehensive evidence assessment nor quality verification of marketed products.

GLP-1 analogue with clinical research and authorised medicinal products.

The linked clinical paper investigates semaglutide in adults with overweight or obesity. The EMA assessment concerns the specific medicinal product Ozempic. Neither the trial nor the authorisation verifies a similarly named research-shop product.

Synthetic heptapeptide investigated in rat models, among other research.

The cited publication investigates BDNF in different brain regions of rats. These are preclinical data. They do not establish cognitive improvement in humans.

Also: Amino acid sequence

The fixed order of amino acids in a peptide or protein chain.

The sequence describes the order in which the individual amino acids are strung together via peptide bonds. It is usually written using standardised one- or three-letter codes per amino acid. Two peptides made of the same amino acids but in a different order count as different molecules, which makes the sequence a key identity marker.

Also: GRF 1-29, GHRH(1-29), Geref (historical brand name)

GHRH-derived peptide investigated in endocrine research.

The linked review places sermorelin in the historical research on childhood growth hormone deficiency. Historical medical literature establishes neither current authorisation status nor the quality of a shop product.

Also: Elamipretide, MTP-131, Bendavia

Elamipretide, a synthetic peptide investigated in studies of mitochondrial disorders.

On 19 September 2025, FDA granted accelerated approval to Forzinity, containing elamipretide, for a defined patient group with Barth syndrome. This US product approval does not apply to research chemicals sold as SS-31.

Water for which sterility is a specified product characteristic.

Sterility and freedom from endotoxins are different properties. Products must be assessed against their specifications; the word “sterile” implies neither universal suitability as a solvent nor a particular shelf life after opening.

Sterility describes the absence of viable microorganisms in a sample, checked through its own dedicated lab test.

The test is independent of purity, identity and endotoxin value, and is documented separately. It matters mainly for lyophilised peptides that are dissolved and handled further in a laboratory setting.

Storage describes how a peptide is kept before use, usually cool, dry and dark depending on its state.

Stability depends on sequence, formulation and conditions, among other factors. The material’s specification and substantiated stability data are decisive.

Also: BI 456906

Dual glucagon and GLP-1 receptor agonist investigated in clinical trials.

The linked phase II trial investigates survodutide as a dual receptor agonist. Trial data concern the tested formulation and population and do not verify the quality of research chemicals.

Also: Thymosin beta-4 fragment, TB4 Frag

A name used in an original analytical paper for an acetylated fragment of thymosin beta-4.

The linked analytical paper identifies an acetylated fragment in a product labelled TB-500. Findings for full-length thymosin beta-4 do not automatically apply to this fragment or other marketed products.

Also: Egrifta, TH9507, Egrifta WR

Synthetic growth hormone-releasing factor analogue investigated in clinical trials.

The cited clinical paper investigates a growth hormone-releasing factor in people with HIV. The clinical context and study preparation limit how findings can be generalised.

Also: External laboratory

A third-party laboratory is an external lab that tests and documents a sample independently of the manufacturer or shop.

If a CoA names an external lab, it is worth checking whether the name is verifiable at all and whether it holds accreditation such as ISO 17025. A blind test is one way to check a result independently on top of that.

Also: Tα1, Zadaxin (brand name)

Peptide from the thymosin system investigated in clinical and preclinical studies.

The linked randomised trial investigates synthetic thymosin alpha-1 in a particular oncology context. Such a finding is not general evidence of immune enhancement and does not verify freely marketed research products.

Also: Thymosin peptides

Thymosins are a family of peptides originally isolated from the thymus gland.

The name covers different peptides originally isolated from thymus material. Alpha and beta thymosins differ in structure and research context. Findings for one thymosin do not automatically apply to others.

Also: LY3298176

Dual GIP and GLP-1 receptor agonist studied in clinical trials.

The linked randomised clinical trial investigates tirzepatide in obesity. Its study formulation and quality controls must be distinguished from freely marketed research chemicals.

Also: Phases I to IV

The four stages of clinical testing: phases I to III before approval, phase IV afterwards in everyday use.

Clinical development is often described in four phases: Phase I mainly investigates safety and tolerability in healthy volunteers or patients. Phase II examines initial evidence of efficacy and further safety questions. Phase III investigates these in larger groups. Phase IV covers studies after approval. The phase alone does not establish the quality of an individual study.

A designation for insulin containing 100 units per millilitre, not a general peptide unit.

U-100 is a concentration designation for insulin products. It is not a general unit of peptide mass. A scale labelled this way cannot be interpreted as a peptide quantity without knowing the substance and its specification.

Also: Small bottle

A vial is a small glass container, usually sealed with a rubber stopper, holding a peptide as powder or solution.

Vials are the standard packaging for lyophilised peptides in the research trade. The rubber stopper allows a closed withdrawal, and the printed label usually carries the batch number and amount. A single vial can be matched to a CoA as long as the batch number lines up.

World Anti-Doping Agency

WADA publishes an annual prohibited list for sport that also includes peptides.

The World Anti-Doping Agency coordinates anti-doping rules in organised sport and updates its prohibited list annually. Several categories cover peptide hormones and related substances, independent of their legal status outside sport. Which specific substance is covered is set out only in the current WADA list itself.

Also: 5-Amino 1MQ, 5A1MQ, NNMT inhibitor

Small molecule investigated as an NNMT inhibitor in preclinical models. Not a peptide.

The linked original paper investigates small-molecule NNMT inhibitors in cellular assays and a diet-induced obesity model in mice. It does not provide clinical evidence for the use of shop products.