Glossary
Words, simply explained
Short, plain-English meanings for the technical words you will meet on this site.
A
- Agonist
- Something that turns on a receptor so the cell responds. Some agonists copy a signal the body already uses.
- Source: National Cancer Institute (NIH) (opens in a new tab)
- Amino acid
- One of the small building blocks that join in chains to make peptides and proteins. Proteins use 20 common kinds.
- Source: National Cancer Institute (NIH) (opens in a new tab)
- Anecdotal
- Based on personal stories rather than a planned study. Stories can point to questions worth studying, but they cannot show what caused an effect.
B
- Bacteriostatic water (BAC water)
- Sterile water with a preservative that slows the growth of bacteria, so one vial can be opened more than once. It is made for mixing medicines that are injected.
- Source: DailyMed (NIH), bacteriostatic water label (opens in a new tab)
- Bioregulator
- A name for a family of very short peptides that came out of decades of research in Russia. Many, such as Epitalon, were made to copy a natural extract from one organ.
- Source: Review on PubMed Central (NIH) (opens in a new tab)
- Blend
- Two or more compounds mixed into one product, in amounts set by its formula. Unlike a stack, you cannot change one ingredient without changing them all.
C
- Clinical trial
- A research study that tests how well a new treatment, test or way to prevent disease works in people.
- Source: National Cancer Institute (NIH) (opens in a new tab)
- COA (certificate of analysis)
- A lab's test report for one batch, so its batch number should match your vial. Purity, identity, amount and toxins from germs are each a separate test, and a report may not show all four.
- Compounding
- When a pharmacy makes its own version of a medicine, often for someone an approved medicine does not suit. These drugs are not FDA-approved, so the FDA does not check that they are safe, work or are well made before sale.
- Source: US Food and Drug Administration (opens in a new tab)
- Concentration
- How much peptide is in each mL of liquid after mixing. Adding more water lowers the concentration but does not change how much peptide is in the vial.
F
- FDA
- The US Food and Drug Administration, the agency that checks that medicines are safe and work. A medicine is FDA-approved only for the uses the FDA has reviewed.
- Source: US Food and Drug Administration (opens in a new tab)
- Food noise
- What people call constant, unwanted thoughts about food that are hard to switch off. It is an everyday phrase, not a formal medical term.
G
- GLP-1 (glucagon-like peptide-1)
- A hormone your gut releases after you eat that helps control blood sugar and helps you feel full. Medicines such as semaglutide copy its effects.
- Source: Review on PubMed Central (NIH) (opens in a new tab)
- Growth hormone (GH)
- A hormone made by the pituitary gland, a small organ at the base of the brain. It drives growth in children and helps keep bones and muscles healthy in adults.
- Source: MedlinePlus (NIH) (opens in a new tab)
H
- Half-life
- How long it takes the amount of a substance in the body to drop by half. It helps explain how long a compound stays around, but it does not directly tell you how long someone will feel an effect.
I
- IGF-1 (insulin-like growth factor 1)
- A hormone that carries out many of growth hormone's effects in the body. Doctors test it to check for growth hormone problems.
- Source: MedlinePlus (NIH) (opens in a new tab)
- In vitro
- Done with cells in a dish or a test tube, not in a living animal or person. Results there often do not carry over to people.
- Source: National Cancer Institute (NIH) (opens in a new tab)
- Insulin syringe
- A small syringe with a fine needle, marked in units instead of mL. On the common U-100 type, 100 units fill 1 mL, so each unit is 0.01 mL.
- Source: US Food and Drug Administration (opens in a new tab)
- International unit (IU)
- A way to measure some vitamins, hormones and drugs, such as hCG, by their effect in the body rather than their weight. An IU is not the same as a unit mark on a syringe.
- Source: National Cancer Institute (NIH) (opens in a new tab)
- Intramuscular
- Into a muscle. An intramuscular injection goes deeper than one under the skin.
- Source: National Cancer Institute (NIH) (opens in a new tab)
L
- Lyophilized
- Freeze-dried into a powder that may look like a small disc or cake. Many peptides ship this way and are mixed with a liquid before use.
M
- Mechanistic
- About the biological process that could explain an effect. It can help explain how something might work, but it is not itself proof of a benefit in people.
- Microgram (mcg)
- A tiny unit of weight: 1,000 mcg make 1 mg. Mixing up mcg and mg makes an amount 1,000 times too big or too small.
- Milligram (mg)
- A small unit of weight, one thousandth of a gram. Peptide vials are usually labeled by how many mg of peptide they hold.
- Milliliter (mL)
- A small unit of liquid, about one fifth of a teaspoon. On a U-100 insulin syringe, 1 mL is 100 units.
- Mitochondria
- Tiny parts inside a cell that make most of the energy the cell uses.
- Source: National Cancer Institute (NIH) (opens in a new tab)
N
- Nasal spray (intranasal)
- Given as a spray into the nose. You may also see the word intranasal.
- Nootropic
- A word for anything people take hoping to improve memory, focus or thinking. The label alone does not mean it works.
O
- Off-label
- Using an approved medicine for a condition, dose or way of taking it that the FDA did not approve. Doctors may prescribe a medicine this way when they judge it right for a patient.
- Source: US Food and Drug Administration (opens in a new tab)
P
- Peptide
- A short chain of amino acids, the building blocks of proteins. The body makes many peptides as signals; others are made in a lab.
- Source: National Cancer Institute (NIH) (opens in a new tab)
- Pin
- You may see “pin” online. It means inject.
- Placebo
- A dummy treatment with no active ingredient, made to look and be given like the real one. Studies compare the two to see what the real treatment adds.
- Source: National Cancer Institute (NIH) (opens in a new tab)
- Plateau
- A stretch when progress, such as weight loss, stops for a while. People often call it a stall.
R
- Randomized controlled trial
- A study that uses chance to decide who gets the treatment and who gets a placebo or another treatment. Using chance makes the groups alike, so the results are fairer to compare.
- Source: National Cancer Institute (NIH) (opens in a new tab)
- Receptor
- A spot on or inside a cell that one kind of signal fits, like a key in a lock. When the signal attaches, the cell responds.
- Source: National Cancer Institute (NIH) (opens in a new tab)
- Reconstitute
- To mix a freeze-dried powder with a liquid, such as BAC water, so it can be measured and used. On this site we usually just say mix.
S
- Secretagogue
- Something that makes a gland release a hormone. Growth hormone secretagogues, such as ipamorelin, prompt the body to release more of its own growth hormone.
- Stack
- A combination of two or more separate compounds used during the same period, each in its own amount. Unlike a blend, each one can be changed or stopped on its own.
- Subcutaneous
- Under the skin. The injection goes into the fatty layer just below the skin, not into a muscle or a vein.
- Source: MedlinePlus (NIH) (opens in a new tab)
T
- Titration
- Starting with a low dose and stepping it up slowly, often over weeks. Each step shows how the body handles it.
- Topical
- Put on the skin, such as a cream or serum, rather than swallowed or injected.
- Source: National Cancer Institute (NIH) (opens in a new tab)
U
- Units (on a syringe)
- The marks on an insulin syringe, which measure liquid, not peptide: on a U-100 syringe, 10 units is 0.1 mL. How much peptide that holds depends on how much water was mixed in.
- Source: US Food and Drug Administration (opens in a new tab)
W
- WADA
- The World Anti-Doping Agency. It keeps the Prohibited List of substances and methods banned in sport and updates it at least once a year.
- Source: World Anti-Doping Agency (opens in a new tab)
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