# Plain-Language Peptide and Biology Glossary

Peptide glossary explaining amino acids, proteins, hormones, receptors, FDA terms and product-quality language in plain English.

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Peptides, hormones, proteins, research products, and injectable medicines are often discussed with words that assume a biology or medical background. Most people were never taught that vocabulary.

This [peptide and biology glossary](https://taylortides.com/molecules/glossary/#glossary-terms) explains the terminology used throughout Taylor Tides. Each entry has two parts:

- **Definition:** what the term means scientifically.
- **What that means:** the useful idea in normal-person language.

The explanations are intentionally brief. They are designed to help you understand educational material and ask better questions, not replace medical advice or a complete science textbook.

## How to Use This Glossary

- Use the letters above to jump to a section.
- Use your browser's Find function to locate a specific word.
- Read the scientific definition first, then the plain-language explanation.
- Follow related links when you want a fuller explanation of a subject.

MIC ingredient and Barth syndrome definitions added October 2, 2026.

Reconstitution terminology updated October 6, 2026.

Amylin and eloralintide definitions added October 8, 2026.

## L

### Lemon Bottle (LemonBottle)

A branded mixture promoted for reducing pockets of fat, rather than a single identified peptide. SID MEDICOS lists riboflavin (vitamin B2), lecithin and bromelain among its ingredients.

**What that means:** What an ingredient does does not establish that the finished mixture safely removes fat. The manufacturer has described its Ampoule Solution as a cosmetic for external use, not intended for injection. Products with similar names should not be assumed to have the same contents.

[Read more about Lemon Bottle](https://taylortides.com/research/lemon-bottle/)

[Official LemonBottle ingredient list](https://www.lemonbottle.net/products/lemon-bottle-fat-dissolver)

### Lipodystrophy

A group of conditions in which the body loses or lacks fat tissue in certain areas or throughout much of the body.

**What that means:** Some forms also involve fat accumulating elsewhere. The type determines which health problems need monitoring and which care may help.

[Read more about Lipodystrophy](https://taylortides.com/research/lipodystrophy/)

[Tesamorelin and HIV-associated lipodystrophy](https://taylortides.com/molecules/peptides/tesamorelin/)

[Cambridge University Hospitals: Lipodystrophy](https://www.cuh.nhs.uk/patient-information/lipodystrophy/)

### Laboratory-Made

Produced or modified through a laboratory or manufacturing process.

**What that means:** A laboratory-made substance may resemble something the body produces naturally. That does not make the two automatically interchangeable.

### L-Carnitine

A substance that helps move certain fats into mitochondria, the parts of cells that release energy from fuel.

**What that means:** The body makes carnitine and also obtains it from food. Its role in using fat for fuel does not establish that a blend containing it causes weight loss.

[Read more about L-Carnitine](https://taylortides.com/guides/mic-injections/#comparison)

[Source for L-Carnitine](https://ods.od.nih.gov/factsheets/Carnitine-HealthProfessional/)

### Lyophilized (Lyo)

Freeze-dried: water has been removed from a frozen product under a vacuum, leaving dry material.

**What that means:** In peptide discussions, lyo may describe the freeze-dried contents of a vial. In laboratory discussions it can also refer to the drying process or equipment. The word alone does not establish purity, sterility or suitability for human use.

[Read more about Lyophilized](https://taylortides.com/guides/peptide-reconstitution/)

[FDA: Lyophilization](https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/inspection-guides/lyophilization-parenteral-793)

## S

### Survodutide (Survo / Surv)

An investigational laboratory-made peptide that activates GLP-1 and glucagon receptors. Its development code is BI 456906.

**What that means:** Researchers are studying how these two hormone signals affect weight, blood sugar and liver disease. Survo and Surv are informal names for the same compound, not separate medicines. Survodutide is not FDA approved.

[Read more about Survodutide](https://taylortides.com/molecules/peptides/survodutide/)

[Survodutide development update](https://www.boehringer-ingelheim.com/us/human-health/metabolic-diseases/new-phase-iii-data-people-obesity-and-diabetes)

### Selank

A laboratory-made seven-amino-acid peptide investigated for effects on anxiety-related and nerve-cell signaling.

**What that means:** Selank research asks whether it changes particular communication processes in the nervous system. It is a different peptide from Semax. Early research does not establish the effects or long-term safety of an online nasal spray or research product.

[Read more about Selank](https://taylortides.com/molecules/peptides/selank/)

[Source for Selank](https://pubmed.ncbi.nlm.nih.gov/26924987/)

### Semax

A laboratory-made seven-amino-acid peptide designed from a modified fragment of adrenocorticotropic hormone, or ACTH.

**What that means:** ACTH is a hormone involved in the body's stress-response system. Semax copies only part of that signal and has been studied for nervous-system effects. It is not the full hormone, and research does not establish broad claims of better memory or focus in healthy people.

[Read more about Semax](https://taylortides.com/molecules/peptides/semax/)

[Source for Semax](https://www.fda.gov/media/193348/download)

### Single-Dose Vial

A vial designed and labeled for one person during one procedure or administration period.

**What that means:** It is not designed to be stored and used repeatedly like a multidose vial.

### SS-31 (Elamipretide)

A laboratory-made four-amino-acid peptide that interacts with cardiolipin, a fat found in the inner membrane of mitochondria.

**What that means:** SS-31 is another name for elamipretide. The prescription product Forzinity received accelerated FDA approval for improving muscle strength in people with Barth syndrome who weigh at least 30 kilograms. That specific approval does not establish general anti-aging benefits or the quality of research vials.

[Read more about SS-31](https://taylortides.com/molecules/peptides/ss-31/)

[Source for SS-31](https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/215244s000lbl.pdf)

### Stability

The ability of a product to retain the characteristics it is supposed to have over a particular period and under specified conditions.

**What that means:** Time, temperature, light, moisture, mixing, and handling can change a product. Looking normal does not prove that it remains stable.

### Sterile and Sterility

Sterile means free from living microorganisms under the standard that applies to the product. Sterility is the condition of being sterile.

**What that means:** Sterility normally cannot be confirmed by looking at a vial. It depends on controlled manufacturing, testing, sealing, storage, and handling.

[Read more about Sterile and Sterility](https://taylortides.com/research/bacteriostatic-water-testing/#sterility-whether-the-test-detects-living-microorganisms)

### Steroid Hormone

A hormone produced from cholesterol rather than from a chain of amino acids.

**What that means:** Steroid describes the hormone’s chemical family. It does not always mean an anabolic steroid associated with muscle building.

### Subcutaneous (SubQ or SC)

Located or administered beneath the skin.

**What that means:** A subcutaneous injection enters the fatty layer beneath the skin rather than a muscle or vein. The route does not prove that a product is safe or appropriate.

### Synthetic

Produced through a chemical or laboratory process.

**What that means:** Synthetic means manufactured. It does not automatically mean dangerous, inferior, effective, or identical to something natural.

### Synthetic Analog

A manufactured substance designed to resemble or behave like another substance.

**What that means:** It is a laboratory-made relative of the original substance. Changes may affect how strongly it acts, how long it lasts, or how the body handles it.

### Scenesse (Afamelanotide implant)

A prescription implant containing afamelanotide, approved in the United States to increase pain-free light exposure in adults with EPP who have a history of painful reactions to light.

**What that means:** A trained healthcare professional places the implant under the skin. Protection from light is still needed. Research vials and tanning products sold as Melanotan 1 are not substitutes for this approved medicine.

[Read more about Scenesse](https://taylortides.com/molecules/peptides/melanotan-1/#scenesse)

[Living with EPP and understanding treatment](https://taylortides.com/research/erythropoietic-protoporphyria/)

[Scenesse prescribing information](https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=94f53286-11dd-7fbb-e053-2a95a90a7c48&version=11)

### Solution

In this context, a liquid mixture in which a substance has dissolved and is evenly distributed.

**What that means:** When a dry peptide dissolves in the specified diluent, the resulting mixture is a solution. The diluent is what you add; the solution is what you have after dissolving. A clear appearance does not establish sterility or suitability for use.

[Read more about Solution](https://taylortides.com/guides/peptide-reconstitution/)

[National Library of Medicine: Solutions](https://www.ncbi.nlm.nih.gov/mesh/68012996)

## D

### Delta sleep-inducing peptide (DSIP)

A peptide made from nine amino acids that has been investigated in sleep research. It is also called emideltide.

**What that means:** The name comes from early sleep experiments, not proof that it improves sleep. Small human studies produced conflicting results, and DSIP is not an FDA-approved medicine.

[Read more about Delta sleep-inducing peptide](https://taylortides.com/molecules/peptides/dsip/)

[Original DSIP research](https://pubmed.ncbi.nlm.nih.gov/265572/)

### DNA (Deoxyribonucleic acid)

The molecule that stores biological instructions used by living organisms.

**What that means:** DNA contains instructions that cells use to make proteins and perform other work.

### Dose and Dosage

A dose is the amount used at a particular time. Dosage includes the amount, schedule, frequency, and duration.

**What that means:** The milligrams printed on a vial do not explain how someone should use it safely. That requires medical information specific to both the product and the person.

### Diluent

A liquid used to dissolve a substance or reduce its concentration.

**What that means:** When liquid is added to a powder, that liquid is the diluent. Different products may require different liquids. Bacteriostatic water, sterile water and saline are not automatically interchangeable.

[Read more about Diluent](https://taylortides.com/guides/bacteriostatic-water/)

[Peptide reconstitution: mixing and storage](https://taylortides.com/guides/peptide-reconstitution/)

[Source for Diluent](https://www.pfizermedical.com/bacteriostatic-water/dosage-admin)

### Dexpanthenol

A substance the body can convert into pantothenic acid, also called vitamin B5.

**What that means:** You may see dexpanthenol listed in some Lipo-C formulas. It is an additional ingredient, separate from the methionine, inositol and choline that give MIC its name.

[Read more about Dexpanthenol](https://taylortides.com/guides/mic-injections/#comparison)

[Source for Dexpanthenol](https://www.cancer.gov/publications/dictionaries/cancer-drug/def/dexpanthenol-mouthwash)

## E

### Emideltide

Another name for delta sleep-inducing peptide, commonly abbreviated DSIP.

**What that means:** Emideltide and DSIP refer to the same peptide, not two different substances or a brand-name medicine.

[Read more about Emideltide](https://taylortides.com/molecules/peptides/dsip/)

[FDA: Emideltide review materials](https://www.fda.gov/advisory-committees/advisory-committee-calendar/july-23-24-2026-meeting-pharmacy-compounding-advisory-committee-07232026)

### Eloralintide (Elora)

An investigational laboratory-made peptide from Eli Lilly designed to activate amylin receptors. It is being studied as a once-weekly injection for weight loss.

**What that means:** Eloralintide copies the fullness hormone amylin. “Elora” is an informal nickname, not an official name. It is not FDA approved.

[Read more about Eloralintide](https://taylortides.com/molecules/peptides/eloralintide/)

[The Lancet: Eloralintide phase 2 trial](https://pubmed.ncbi.nlm.nih.gov/41207310/)

### Effectiveness

How well something produces the desired result when it is actually used.

**What that means:** A scientific explanation of how something might work does not prove its effectiveness. Research must show that it helps people in a meaningful way.

### Endocrine System

The network of organs and tissues that produces hormones and responds to them.

**What that means:** It is a chemical communication system. It helps coordinate growth, metabolism, reproduction, stress, sleep, and blood-sugar control.

### Endotoxin

Material from certain bacteria that can cause inflammation and potentially dangerous reactions.

**What that means:** Endotoxins may be present even when a product looks clean and clear. Chemical-purity testing does not necessarily detect them.

[Read more about Endotoxin](https://taylortides.com/research/bacteriostatic-water-testing/#endotoxins-bacterial-material-that-requires-a-separate-test)

### Enzyme

A biological helper, usually a protein, that allows a particular chemical change to happen faster.

**What that means:** Enzymes keep the body’s work moving. Different enzymes help digest food, release energy, repair tissue, copy biological instructions, and perform thousands of other jobs.

### Essential Amino Acid

An amino acid the body cannot produce in sufficient amounts and must obtain from food.

**What that means:** Essential does not mean more important than every other amino acid. It means the body needs an outside source.

### Erythropoietic Protoporphyria (EPP)

A rare inherited condition in which protoporphyrin builds up in the body and can cause severe pain when it absorbs light.

**What that means:** Exposure to light can be intensely painful even when the skin shows little change. Care includes protection from light, medical follow-up and discussion of available treatments.

[Read more about Erythropoietic Protoporphyria](https://taylortides.com/research/erythropoietic-protoporphyria/)

[Afamelanotide, Melanotan 1 and Scenesse](https://taylortides.com/molecules/peptides/melanotan-1/)

[GeneReviews: Erythropoietic protoporphyria](https://www.ncbi.nlm.nih.gov/books/NBK100826/)

## O

### Obstructive sleep apnea (OSA)

A condition in which the upper airway repeatedly narrows or closes during sleep, reducing or stopping airflow.

**What that means:** Breathing is interrupted because the passage for air becomes blocked. A sleep evaluation helps identify the condition and guide treatment.

[Read more about Obstructive sleep apnea](https://taylortides.com/research/obstructive-sleep-apnea/)

[Tirzepatide and the specific approved use of Zepbound](https://taylortides.com/molecules/peptides/tirzepatide/)

[NHLBI: Sleep apnea](https://www.nhlbi.nih.gov/health/sleep-apnea)

### Off-Label Use

Use of an FDA-approved medication in a way that does not appear in its approved labeling.

**What that means:** A licensed medical professional may prescribe an approved medicine for a different use based on medical judgment. This is not the same as using a product that has never received FDA approval.

## A

### Accelerated Approval

An FDA pathway that can approve certain drugs for serious conditions using evidence that predicts a likely benefit. Additional studies may still be required.

**What that means:** The FDA may approve a promising medicine before every long-term question has been answered. Continued approval may depend on later research confirming that it helps people.

### Agonist

A substance that activates a receptor and causes a response.

**What that means:** If a receptor works somewhat like a biological switch, an agonist turns it on. What happens next depends on the receptor and where it is located.

### Amino Acid

A small molecule the body can use by itself or connect with others to make peptides and proteins.

**What that means:** Amino acids are small building pieces. Their order helps determine what the finished peptide or protein can do.

### Amylin

A hormone the pancreas releases together with insulin after eating. It helps create a feeling of fullness, slows how quickly food leaves the stomach and helps limit blood-sugar rises after meals.

**What that means:** Amylin is one of the body’s natural “I have had enough” signals. Several experimental weight-loss medicines, including cagrilintide and eloralintide, are designed to copy it.

[Cagrilintide](https://taylortides.com/molecules/peptides/cagrilintide/)

[Eloralintide](https://taylortides.com/molecules/peptides/eloralintide/)

### Analog

A version of a substance that is similar to the original but not completely identical.

**What that means:** Scientists may modify a natural substance so that it lasts longer or behaves differently. The modified version is called an analog.

### Angiogenesis

The process of forming new blood vessels from existing blood vessels.

**What that means:** The body creates new pathways for blood to reach tissues. This can support healing, but blood-vessel growth can also matter in diseases such as cancer.

### Antibody

A protein that recognizes a specific biological target.

**What that means:** Antibodies help the immune system identify specific targets. Laboratory-made antibodies are also used in medical tests and some medicines.

### Antioxidant

A substance that can help limit certain types of cell damage caused by unstable molecules.

**What that means:** Antioxidants participate in the body’s chemical defenses. Calling something an antioxidant does not prove that taking or injecting it improves health.

## B

### Barth Syndrome

A rare inherited condition that disrupts mitochondria, the parts of cells that help release energy from food. It can affect the heart, muscles, growth and immune defenses.

**What that means:** People with Barth syndrome may have a weakened heart, muscle weakness and too few of certain infection-fighting white blood cells. Symptoms and severity vary. The condition is discussed in our SS-31 guide because of its connection to research on elamipretide and the prescription medicine Forzinity.

[Read more about Barth Syndrome](https://taylortides.com/research/barth-syndrome/)

[MedlinePlus Genetics: Barth syndrome](https://medlineplus.gov/genetics/condition/barth-syndrome/)

### Bacteriostatic

Able to slow the growth or reproduction of bacteria without necessarily killing all bacteria.

**What that means:** A bacteriostatic ingredient helps control bacterial growth. It does not prevent every form of contamination or make careless handling safe.

### BDNF (Brain-derived neurotrophic factor)

Brain-derived neurotrophic factor is a protein involved in the health and adaptability of certain nerve cells.

**What that means:** BDNF helps some brain and nerve cells survive, function, and adapt. A claim that something affects BDNF does not prove better memory, concentration, or mood.

### Benzyl Alcohol

A preservative used in some medications and multidose injectable products.

**What that means:** It can help limit bacterial growth after a vial is opened. The amount and safety restrictions depend on the specific product.

[Read more about Benzyl Alcohol](https://taylortides.com/research/bacteriostatic-water-testing/#benzyl-alcohol-how-much-preservative-is-present)

### Bioidentical Hormone

A manufactured hormone with the same chemical structure as a hormone produced by the human body.

**What that means:** Bioidentical describes its structure. It does not automatically mean safer, more effective, FDA-approved, or appropriate for everyone.

### BPC-157

A laboratory-made peptide containing 15 amino acids, studied for possible effects on tissue repair and the digestive system.

**What that means:** BPC-157 is an experimental compound. Most of its research involves animals, and reliable human evidence remains limited. Results in injured animal tissue do not establish that it heals an injury in a person.

[Read more about BPC-157](https://taylortides.com/molecules/peptides/bpc-157/)

[Source for BPC-157](https://www.fda.gov/media/193343/download)

### Batch or Lot Number

A code that identifies a production batch or a defined portion of it and connects the product to its manufacturing records.

**What that means:** This code helps you match a vial to the correct test report. A report for a different batch does not establish the results for yours. The code itself is not a quality test or an expiration date.

[Read more about Batch or Lot Number](https://taylortides.com/research/bacteriostatic-water-testing/#what-should-you-check-before-trusting-a-test-report)

[Source for Batch or Lot Number](https://www.ecfr.gov/current/title-21/chapter-I/subchapter-C/part-210/section-210.3)

## C

### Cagrilintide (Cagri)

A laboratory-made, long-acting version of amylin, a hormone involved in feeling full after eating.

**What that means:** Cagrilintide was designed to extend one of the body's fullness signals. It has been studied on its own and with semaglutide for weight management. The combination is called CagriSema; cagrilintide and semaglutide are different molecules.

[Read more about Cagrilintide](https://taylortides.com/molecules/peptides/cagrilintide/)

[Source for Cagrilintide](https://pubmed.ncbi.nlm.nih.gov/34798060/)

### Cardiolipin

A type of fat found mainly in the inner wall of mitochondria.

**What that means:** Cardiolipin helps maintain part of the cell’s energy-producing equipment. It appears in research involving SS-31 and mitochondrial function.

### Cell

The smallest living unit capable of performing the basic work required for life.

**What that means:** Your body is made from tiny living units. Different cells perform different jobs, such as carrying oxygen, producing hormones, or fighting infection.

### Certificate of Analysis (COA)

A report showing selected laboratory results for a particular sample or production batch.

**What that means:** A COA can provide useful information, but it does not automatically prove safety, sterility, effectiveness, correct storage, or suitability for human use.

[Read more about Certificate of Analysis](https://taylortides.com/research/bacteriostatic-water-testing/#how-do-you-read-a-certificate-of-analysis)

### Chemical Reaction

A process that changes one or more substances into different substances.

**What that means:** Your body is constantly separating materials, combining them, and turning them into something different. Those changes are chemical reactions.

### Clinical Trial

A planned study involving people that investigates a treatment, test, product, or health question.

**What that means:** Researchers follow a written plan to learn what happens in people. A registered study is not necessarily finished, and one trial rarely answers every question.

### Coenzyme

A small helper molecule that some enzymes need to perform their work.

**What that means:** The enzyme is the main tool, and the coenzyme helps that tool work. NAD+ is a coenzyme.

### Collagen

A family of proteins that helps provide structure and strength to skin, tendons, ligaments, bones, and other tissues.

**What that means:** Collagen is part of the body’s support framework. A collagen-related laboratory result does not automatically prove visible or meaningful tissue repair.

### Compounded Drug

A medication prepared to meet a particular medical need that an available FDA-approved product cannot meet.

**What that means:** Compounding can serve legitimate needs. Compounded drugs are not FDA-approved, and the FDA does not review them for safety, effectiveness, or quality before they reach the market.

### Concentration

The amount of a substance contained in a particular amount of liquid.

**What that means:** Concentration tells you how much of an ingredient exists within a measured volume. It is different from the total amount contained in the vial.

### Contamination

The unwanted presence of microorganisms, chemicals, particles, or other materials.

**What that means:** A vial may contain the expected ingredient and still be unsafe if unwanted material entered during manufacturing, storage, preparation, or handling.

### Choline

A nutrient used to build cell membranes, support nerve communication and transport fats.

**What that means:** Choline helps make the outer boundaries of cells and a chemical messenger used by nerves. It is the C in MIC.

[Read more about Choline](https://taylortides.com/guides/mic-injections/#what-is)

[Source for Choline](https://ods.od.nih.gov/factsheets/Choline-HealthProfessional/)

## F

### FDA-Approved

Reviewed and authorized by the FDA for a specific product, use, population, formulation, and set of conditions.

**What that means:** FDA approval is specific. Approval of one medicine does not automatically cover similar molecules, research products, compounded versions, doses, or health claims.

### Formulation

The complete recipe and physical form of a finished product.

**What that means:** The formulation includes the active ingredient, amount, inactive ingredients, and delivery form. Products with similar names may have different formulations.

## G

### GHK-Cu (Copper tripeptide)

A complex formed when a three-amino-acid peptide called GHK binds copper.

**What that means:** GHK is the small carrier and Cu is the chemical symbol for the copper it holds. GHK-Cu is studied in skin and tissue biology. Findings about creams or laboratory cells do not establish the benefits or safety of injecting it.

[Read more about GHK-Cu](https://taylortides.com/molecules/peptides/ghk-cu/)

[Source for GHK-Cu](https://pubchem.ncbi.nlm.nih.gov/compound/Copper-tripeptide)

### GIP (Glucose-dependent insulinotropic polypeptide)

A hormone released by the digestive system after eating.

**What that means:** GIP is one of the signals the body uses to manage food and blood sugar. Some researched medicines are designed to activate the receptor that receives this signal.

### GLOW Peptide Blend

A supplier-created name commonly used for a mixture of GHK-Cu, BPC-157 and TB-500.

**What that means:** GLOW contains separate compounds combined in one product. It is not a new molecule or a standardized medical name. Formulas can differ, and research on an ingredient does not establish the effects of the complete mixture.

[Read more about GLOW Peptide Blend](https://taylortides.com/molecules/peptides/glow-peptide/)

[FDA information on the individual ingredients](https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks)

### GLP-1 (Glucagon-like peptide-1)

A hormone involved in appetite, digestion, and blood-sugar control.

**What that means:** GLP-1 is a message the body naturally sends after eating. A GLP-1 receptor agonist is designed to activate the receptor that receives that message.

### Glucagon

A hormone that helps increase available blood sugar when the body needs fuel.

**What that means:** Glucagon helps prevent blood sugar from falling too low. It often works in balance with insulin.

### Glutathione (GSH in its reduced form)

A peptide made from three amino acids that cells use to help manage potentially damaging chemical reactions.

**What that means:** The body makes glutathione as part of its antioxidant defenses. Having an important natural function does not mean that extra glutathione, or an injection of it, provides a proven benefit for every purpose.

[Read more about Glutathione](https://taylortides.com/molecules/peptides/glutathione/)

[Source for Glutathione](https://www.ncbi.nlm.nih.gov/books/NBK28123/)

### GnRH (Gonadotropin-releasing hormone)

A signal from the brain that begins part of the body’s reproductive communication process.

**What that means:** GnRH tells the pituitary gland to send additional messages to the ovaries or testicles.

### Growth Factor

A signal that influences how certain cells grow, survive, change, or participate in repair.

**What that means:** A growth factor does not simply make the entire body grow. Its effects depend on the particular signal, cell, tissue, amount, and situation.

## H

### Hormone

A chemical message that influences what another cell, tissue, or organ does.

**What that means:** Hormone describes a job, not one type of material. A hormone can also be a peptide, protein, steroid, or another kind of molecule.

## I

### Identity

Confirmation of what substance a product or sample actually contains.

**What that means:** Identity testing asks whether the vial contains what its label claims. It does not prove the correct amount, purity, sterility, safety, or effectiveness.

### IGF-1 (Insulin-like growth factor 1)

A hormone involved in growth and tissue development. Growth hormone influences how much the body produces.

**What that means:** IGF-1 carries some growth-related messages. A higher level is not automatically better or safer.

### Intramuscular (IM)

Administered into a muscle.

**What that means:** This describes where something is administered. It does not describe what the substance is or prove that it is appropriate to inject.

### Intranasal

Administered through the nose.

**What that means:** A nasal spray is intranasal. Using the nose does not guarantee that the ingredient reaches its intended destination or produces the claimed result.

### Intravenous (IV)

Administered directly into a vein.

**What that means:** This route places something into the bloodstream. It does not prove that the product is necessary, sterile, safe, or effective.

### Investigational

Still being formally studied and not established or approved for the use being discussed.

**What that means:** Investigational means important questions remain unanswered. It does not mean proven, harmless, or secretly approved.

### Inositol

A naturally occurring substance involved in signals that help cells respond to messages.

**What that means:** Cells use inositol-containing molecules in their communication systems. Inositol is the I in MIC. Its normal role does not tell us what injecting a blend will achieve.

[Read more about Inositol](https://taylortides.com/guides/mic-injections/#what-is)

[Source for Inositol](https://pubchem.ncbi.nlm.nih.gov/compound/Inositol)

## K

### Kisspeptin

A family of natural peptide signals that helps regulate the body's reproductive hormone system.

**What that means:** Kisspeptin helps start a chain of messages from the brain that influences reproductive hormones. Forms such as kisspeptin-10 and kisspeptin-54 have different lengths. Research on a particular form and population does not establish that every kisspeptin product improves fertility or sexual function.

[Read more about Kisspeptin](https://taylortides.com/molecules/peptides/kisspeptin/)

[Source for Kisspeptin](https://pubmed.ncbi.nlm.nih.gov/16174713/)

### KLOW Peptide Blend

A supplier-created name commonly used for a mixture of GHK-Cu, BPC-157, TB-500 and KPV.

**What that means:** KLOW generally adds KPV to the ingredients commonly associated with GLOW. The name does not guarantee a particular formula or amount. Combining compounds does not prove that they work better together or that the mixture is safe.

[Read more about KLOW Peptide Blend](https://taylortides.com/molecules/peptides/klow-peptide/)

[FDA information on the individual ingredients](https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks)

### KPV

A three-amino-acid peptide corresponding to the end of the natural hormone alpha-melanocyte-stimulating hormone, or alpha-MSH.

**What that means:** The letters identify its three pieces: lysine, proline and valine. KPV is a small fragment of a longer body signal. Cell and animal studies have examined inflammation, but those findings do not establish a treatment benefit in people.

[Read more about KPV](https://taylortides.com/molecules/peptides/kpv/)

[Source for KPV](https://pubmed.ncbi.nlm.nih.gov/18061177/)

## M

### Mechanism of Action

The biological process through which something is believed or known to produce an effect.

**What that means:** The mechanism explains how something might work. It does not prove that it produces a useful result in people.

### Melanotan 1 (MT-1; afamelanotide)

A laboratory-made peptide that imitates a natural signal involved in producing melanin, the pigment that gives skin its color.

**What that means:** Afamelanotide is used in the prescription implant Scenesse for a specific light-sensitivity disorder called erythropoietic protoporphyria. That approval does not cover tanning products or research vials sold as Melanotan 1.

[Read more about Melanotan 1](https://taylortides.com/molecules/peptides/melanotan-1/)

[EPP symptoms, treatment and everyday life](https://taylortides.com/research/erythropoietic-protoporphyria/)

[Source for Melanotan 1](https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/210797s007lbl.pdf)

### Melanotan 2 (MT-2; Melanotan II)

A laboratory-made peptide with a ring-shaped structure that activates melanocortin receptors, which receive signals involved in skin pigmentation and other body functions.

**What that means:** MT-2 affects more than skin color. It is a different molecule from Melanotan 1, and neither a tanning claim nor a darker skin tone establishes that a product is safe. Serious adverse events have been reported with Melanotan II.

[Read more about Melanotan 2](https://taylortides.com/molecules/peptides/melanotan-2/)

[Source for Melanotan 2](https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks)

### Metabolism

All the chemical work the body performs to obtain energy, build and maintain tissues, and process substances.

**What that means:** Metabolism is not a single switch controlling body weight. It includes thousands of connected jobs happening throughout the body.

### Microbial Contamination

The unwanted presence of bacteria, fungi, or other microorganisms.

**What that means:** Microorganisms may be present even when they cannot be seen. Injectable products require strong protections because they bypass some of the body’s normal barriers.

### Milligram and Milliliter (mg and mL)

A milligram measures weight. A milliliter measures liquid volume.

**What that means:** Ten milligrams and ten milliliters are different measurements. One tells you how much a substance weighs. The other tells you how much space a liquid occupies.

### Mitochondria

Small structures inside most cells that help convert energy from food into a form the cells can use.

**What that means:** Mitochondria help power cellular work. They also participate in communication, stress responses, and other processes inside cells.

### Molecule

Two or more atoms joined together as one unit.

**What that means:** Molecule is a very broad category. Water, vitamin B12, peptides, and proteins are all molecules, although they have very different sizes and jobs.

### Monoclonal Antibody

An antibody produced in a laboratory and designed to recognize one specific target.

**What that means:** “Mono” means one. “Clonal” means copies made from the same original source. Together, the words describe matching antibodies built to recognize the same target.

### MOTS-C

A naturally occurring 16-amino-acid peptide whose genetic instructions are found in mitochondrial DNA.

**What that means:** Mitochondria help cells obtain usable energy. MOTS-C is being investigated as one of their signals involved in energy use and responses to stress. Findings in cells and mice do not establish that taking MOTS-C improves human fitness, weight or longevity.

[Read more about MOTS-C](https://taylortides.com/molecules/peptides/mots-c/)

[Source for MOTS-C](https://pubmed.ncbi.nlm.nih.gov/25738459/)

### Multidose Vial

A vial designed and labeled to contain more than one dose.

**What that means:** Multidose does not mean unlimited use. The label, storage instructions, handling requirements, and period after opening still matter.

### Microorganism

An organism too small to see without a microscope, such as a bacterium or microscopic fungus.

**What that means:** Microorganisms can be present without a visible change in the liquid. A vial looking clear does not establish that it is free of them.

[Read more about Microorganism](https://taylortides.com/research/bacteriostatic-water-testing/#sterility-whether-the-test-detects-living-microorganisms)

[Source for Microorganism](https://www.cancer.gov/publications/dictionaries/cancer-terms/def/microorganism)

### Methionine

An amino acid the body uses to make proteins and must obtain through the diet.

**What that means:** Methionine is one of the small building pieces used to assemble proteins. It is the M in MIC.

[Read more about Methionine](https://taylortides.com/guides/mic-injections/#what-is)

[Source for Methionine](https://pubchem.ncbi.nlm.nih.gov/compound/methionine)

## N

### Natural

Produced by nature or a living organism rather than manufactured as a finished product.

**What that means:** Natural describes where something comes from. It does not automatically mean safe, effective, pure, or appropriate.

### Neurasthenia

An older diagnostic term for persistent exhaustion and weakness, often accompanied by difficulty concentrating, irritability and other physical symptoms.

**What that means:** Historically called nervous exhaustion, the term has been used differently across countries and time periods. It is not simply another name for ordinary tiredness or myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The Selank article discusses a small human study that included people with this diagnosis.

[Read more about Neurasthenia](https://taylortides.com/molecules/peptides/selank/#human-research)

[Source for Neurasthenia](https://www.ncbi.nlm.nih.gov/mesh/D009440)

### Neurotransmitter

A chemical message used by nerve cells to communicate with other cells over a very short distance.

**What that means:** Neurotransmitters help nerve cells send messages. They are related to hormones, but the two terms describe different forms of communication.

### Nonessential Amino Acid

An amino acid the body can normally produce in sufficient amounts.

**What that means:** Nonessential does not mean unnecessary. It means the body does not normally depend entirely on food to obtain it.

## P

### Peptide

A short chain of amino acids joined together.

**What that means:** A peptide is a small, ordered chain of biological building pieces. The word describes its structure. It does not indicate whether the peptide is useful, proven, safe, or approved.

### Peptide Bond

The chemical connection joining one amino acid to another.

**What that means:** It is the link used to assemble amino acids into peptides and proteins.

### Peptide Fragment

A shorter section taken from a larger peptide or protein.

**What that means:** A fragment contains only part of the original chain. It may not behave exactly like the complete substance.

### Placebo

An inactive comparison designed to resemble the treatment being studied.

**What that means:** A placebo helps separate the treatment’s effects from expectations, natural changes, additional care, and other influences.

### Polypeptide

A longer chain of amino acids that can fold or combine with other chains to form a protein.

**What that means:** Peptide, polypeptide, and protein describe related structures of different sizes and complexity. The exact dividing lines are not identical across every scientific source.

### Potency

The expected strength or biological activity of a substance.

**What that means:** Potency asks whether the product has the expected strength. It does not answer whether it has the correct identity, is pure, is sterile, or is safe.

### Precursor

A substance the body can use to produce another substance.

**What that means:** A precursor is starting material. Providing more starting material does not guarantee that the body will produce more of the finished substance.

### Protein

One or more long chains of amino acids folded into a working structure.

**What that means:** Amino acids provide the pieces. Their order helps create the shape, and the shape helps the protein perform its job.

### PT-141 (Bremelanotide)

A laboratory-made peptide that activates melanocortin receptors, part of a signaling system involved in several functions, including sexual response.

**What that means:** Bremelanotide is the active ingredient in Vyleesi, a prescription medicine for a specific low-sexual-desire disorder in certain premenopausal women. A research vial labeled PT-141 is not the approved prescription product, and that approval is not a general sexual-performance claim.

[Read more about PT-141](https://taylortides.com/molecules/peptides/pt-141/)

[Source for PT-141](https://medlineplus.gov/druginfo/meds/a619054.html)

### Purity

The amount of the intended substance compared with unwanted substances in a sample.

**What that means:** High purity is useful information. It does not automatically prove identity, potency, sterility, safety, or effectiveness.

### pH

A measure of how acidic or alkaline a liquid is. Under ordinary room-temperature conditions, 7 is neutral; lower values are acidic and higher values are alkaline.

**What that means:** pH describes one chemical property of water. It does not tell you whether bacteria or endotoxins are present, or whether the correct amount of preservative was added.

[Read more about pH](https://taylortides.com/research/bacteriostatic-water-testing/#ph-how-acidic-or-alkaline-the-water-is)

[Source for pH](https://www.usgs.gov/water-science-school/science/ph-and-water)

### Preservative

An ingredient added to help prevent a product from deteriorating. Some preservatives limit the growth of bacteria or other microorganisms.

**What that means:** Benzyl alcohol serves this role in bacteriostatic water. Having a preservative does not replace sterile manufacturing, correct storage or careful handling.

[Read more about Preservative](https://taylortides.com/research/bacteriostatic-water-testing/#benzyl-alcohol-how-much-preservative-is-present)

[Source for Preservative](https://www.pfizermedical.com/bacteriostatic-water/description)

## R

### Receptor

A structure on or inside a cell that recognizes a particular signal and helps the cell respond.

**What that means:** A receptor works somewhat like a receiver waiting for the right message. The response depends on the receptor, the cell, and the situation.

### Recombinant Protein

A protein produced by giving specially prepared cells the genetic instructions needed to make it.

**What that means:** Scientists place the recipe for a protein into cells capable of manufacturing it. Recombinant explains how the protein was produced, not whether the finished product is approved, pure, safe, or effective.

### Reconstitution (Recon)

Adding a specific liquid to a dry medication or laboratory product to turn it into a liquid.

**What that means:** Reconstitution is more specific than simply adding water. The correct liquid, amount, handling, storage, and final concentration depend on the exact product.

[Read more about Reconstitution](https://taylortides.com/guides/peptide-reconstitution/)

### Research Use Only

Labeling that says a product is intended for laboratory research rather than diagnosis, treatment, or human consumption.

**What that means:** The phrase does not prove identity, purity, sterility, legal compliance, or medical suitability. It also does not turn an unapproved product into an approved medicine.

### Retatrutide (Reta; LY3437943)

An investigational laboratory-made peptide that activates receptors for three hormones: GLP-1, GIP, and glucagon.

**What that means:** One molecule acts on three of the body’s message-receiving systems involved in appetite, blood sugar, and energy use. Retatrutide is being studied for obesity, type 2 diabetes, and related conditions. It is not FDA-approved, and its research does not establish the safety or contents of products sold online.

[Read more about Retatrutide](https://taylortides.com/molecules/peptides/retatrutide/)

[Source for Retatrutide](https://www.lilly.com/news/stories/what-to-know-about-retatrutide)

## T

### TB-500

A name used for a manufactured peptide fragment corresponding to part of thymosin beta-4, a larger protein involved in cell activity.

**What that means:** The FDA identifies TB-500 as the seven-amino-acid fragment LKKTETQ. It should not be treated as interchangeable with full-length thymosin beta-4. Evidence about the larger protein does not automatically apply to a product labeled TB-500.

[Read more about TB-500](https://taylortides.com/molecules/peptides/tb-500/)

[Source for TB-500](https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks)

### Tesamorelin

A laboratory-made peptide that stimulates the release of the body's own growth hormone.

**What that means:** Tesamorelin imitates a natural message called growth hormone-releasing hormone. Prescription tesamorelin is used to reduce excess abdominal fat in adults with HIV-associated lipodystrophy, a disorder of fat distribution. It is not a general weight-loss medicine.

[Read more about Tesamorelin](https://taylortides.com/molecules/peptides/tesamorelin/)

[Lipodystrophy: diagnosis, treatment and support](https://taylortides.com/research/lipodystrophy/)

[Source for Tesamorelin](https://medlineplus.gov/druginfo/meds/a611035.html)

### Tirzepatide

A laboratory-made peptide that activates receptors for two hormones, GIP and GLP-1, involved in blood-sugar control and appetite.

**What that means:** One molecule acts on two message-receiving systems. Tirzepatide is the active ingredient in the prescription medicines Mounjaro and Zepbound, which have specific approved uses. Those approvals do not cover every compounded preparation or research product sold under the same ingredient name.

[Read more about Tirzepatide](https://taylortides.com/molecules/peptides/tirzepatide/)

[Obstructive sleep apnea: symptoms, testing and treatment](https://taylortides.com/research/obstructive-sleep-apnea/)

[Source for Tirzepatide](https://pi.lilly.com/us/mounjaro-uspi.pdf)

### Topical

Applied to a body surface, usually the skin.

**What that means:** Evidence involving a topical cream or serum does not automatically apply to an injection, nasal spray, or oral product.

## V

### Visceral Fat

Fat stored deep inside the abdomen around the internal organs.

**What that means:** Visceral fat is different from the softer fat located directly beneath the skin. Changing one type of fat may not produce the same change in total body weight.

### Vitamin

A nutrient the body needs in small amounts and generally cannot produce in sufficient quantities by itself.

**What that means:** Vitamins help the body perform essential work. More is not always better, and treating a deficiency does not prove a benefit for someone who already has enough.

### Vitamin B12

A vitamin needed for healthy nerve function, red blood cell formation and the production of DNA, the material that carries genetic instructions.

**What that means:** Too little B12 can cause tiredness and weakness. Extra B12 does not improve energy or endurance in people who already have enough. MIC+B12 includes this vitamin in addition to the three MIC ingredients.

[Read more about Vitamin B12](https://taylortides.com/guides/mic-injections/#energy)

[Source for Vitamin B12](https://ods.od.nih.gov/factsheets/VitaminB12-Consumer/)

## W

### Wolverine Stack

An informal name commonly used for a combination of BPC-157 and TB-500.

**What that means:** A stack groups separate compounds; it does not create a new peptide. The name is not a standardized formula, so it cannot confirm a particular product's contents. Research on either ingredient does not prove that the combination heals injuries or is safe.

[Read more about Wolverine Stack](https://taylortides.com/molecules/peptides/bpc-157/#wolverine)

[FDA information on the individual ingredients](https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks)

## The Simple Takeaway

You do not need a biology degree to understand the basic questions surrounding peptides, hormones, proteins, research products, or injectable medicines. You do need clear definitions and enough context to recognize what a scientific term does and does not prove.

When an unfamiliar word appears elsewhere on Taylor Tides, return to this glossary. The goal is not to turn you into a scientist. It is to make the information easier to understand and harder to misrepresent.

## Related Reading

- [Explore the Molecule Library](https://taylortides.com/molecules/)
- [What Are Peptides?](https://taylortides.com/molecules/peptides/)
- [What Are Amino Acids?](https://taylortides.com/molecules/amino-acids/)
- [What Are Proteins?](https://taylortides.com/molecules/proteins/)
- [What Are Hormones?](https://taylortides.com/molecules/hormones/)
- [What Are Enzymes?](https://taylortides.com/molecules/enzymes/)

Educational Notice
This glossary provides general educational definitions. It is not medical advice, a diagnosis, prescribing guidance, dosing guidance, treatment instructions, or a recommendation to use any medication, peptide, supplement, research product, injection, or infusion.

Definitions describe terms in general. Their meaning may be narrower or more specific in a particular study, product label, clinical situation, or medical conversation. Questions about personal health or product use should be discussed with a qualified healthcare professional.

## Sources and Further Reading

- [National Human Genome Research Institute: Talking Glossary of Genomic and Genetic Terms](https://www.genome.gov/genetics-glossary)
- [National Cancer Institute: Dictionary of Cancer Terms](https://www.cancer.gov/publications/dictionaries/cancer-terms)
- [U.S. Food and Drug Administration: Investigational New Drug information](https://www.fda.gov/drugs/types-applications/investigational-new-drug-ind-application)
- [U.S. Food and Drug Administration: Drug compounding information](https://www.fda.gov/drugs/human-drug-compounding/drug-compounding-and-drug-shortages)
- [MedlinePlus Medical Encyclopedia](https://medlineplus.gov/encyclopedia.html)
- [Centers for Disease Control and Prevention: Injection Safety](https://www.cdc.gov/injection-safety/about/index.html)

**Author:** TaylorTides. **Medical review status:** Not reviewed by a licensed clinician. **Foundational terminology reviewed:** September 2, 2026. **New peptide, blend and laboratory-testing entries reviewed:** September 30, 2026.