Glossary

Sterile water with a tiny amount of preservative, used to mix powdered peptides.

One vial holding more than one compound, mixed together by the seller. Working out a dose means working out each ingredient separately, because they are rarely present in equal amounts.

How strong the mixed peptide is, in milligrams per milliliter (mg/mL). More water makes it weaker; less water makes it stronger.

A stretch of time using a compound followed by a break. Most cycling patterns come from community practice. Very few have been tested.

Adding more liquid to make a mix weaker. The amount of peptide in the vial does not change. It is just spread through more water, so each draw is bigger.

Freeze-dried into a powder so it keeps longer. That is the white cake or dust in the bottom of an unmixed vial.

Units of dose. 1 milligram (mg) equals 1,000 micrograms (mcg).

Mixing a powdered peptide with liquid (bacteriostatic water) so it can be drawn into a syringe.

Using more than one compound at the same time. Almost no combinations have been tested together in people, so a stack is usually built on guesswork.

Water with nothing added to stop bacteria growing. It works for a single dose, but a vial mixed with it should not be kept and used again.

Starting at a low dose and increasing it slowly over time so your body adjusts and side effects stay mild.

The small amount of liquid left sitting inside the needle and hub after you inject. On very small doses it can be a real share of what you meant to take.

The spot on the body where you inject. Moving it around gives the skin and fat underneath time to recover between doses.

An injection into a muscle, using a longer needle.

An injection into a vein. It needs training and equipment and is not something to do at home.

An injection just under the skin, into the fat layer, usually with a short, thin insulin needle.

The marks on an insulin syringe. 100 units equals 1 mL. They measure how much liquid you draw, not the dose in milligrams.

Something that switches a receptor on. The opposite is an antagonist. It blocks the receptor instead.

The building blocks that link together in a chain to make a peptide or a protein. The order they sit in is what makes one peptide different from another.

A hormone released alongside insulin that slows the stomach emptying and reduces appetite. Several weight loss compounds copy it.

A compound built to copy a natural one with small deliberate changes, usually so it lasts longer or holds onto its target more tightly.

A large immune protein, far bigger than a peptide, engineered to lock onto one specific target. These are made by drug companies and are not sold as research powders.

How much of a dose actually reaches your bloodstream. Most peptides survive stomach acid badly, so most of them are injected instead of swallowed.

Very short peptides from a Russian research tradition, usually two to four amino acids long, sold for supporting a specific organ. Human evidence is thin and most of it is published in Russian.

Short for Drug Affinity Complex. An attachment added to a peptide so it grabs onto a blood protein and stays in the body for days instead of minutes.

A short piece cut out of a larger natural protein. A fragment can behave very differently from the whole protein it came from, so evidence about one does not transfer to the other.

The hunger hormone. Some growth hormone compounds work by copying it, so they can make you noticeably hungrier.

A natural signal telling the pituitary gland to release growth hormone. Several compounds copy it.

A second, separate signal that also triggers growth hormone release, through a different door than GHRH. This is why the two types are often used together.

A natural gut hormone that lowers appetite and blood sugar. Drugs that copy it, like semaglutide, are used for weight loss.

A compound that nudges your body to release more of its own growth hormone, rather than injecting the hormone itself.

How long a compound stays active in your body. A longer half-life means you inject less often. See the half-life chart for every compound.

A natural brake on muscle growth. Several compounds are built to block it, though human results have been far smaller than the animal work suggested.

A peptide is a short chain of amino acids. A few items here (like MK-677 or methylene blue) are small molecules, not true peptides, but people use them the same way.

A docking point on a cell that a compound attaches to. If a cell has no matching receptor, the compound does nothing to it.

Research done in rats, mice or other animals. Most findings do not repeat in people, so an animal result is a reason to keep looking. It is not a reason to act.

A study that gives a treatment to people under a written plan and measures what happens. It is the only kind of evidence that can show something works in humans.

The result a trial said in advance that it would measure. A study can be reported as positive and still have missed the endpoint it set out to hit.

Done in a dish or a test tube, on cells outside a living body. It is the earliest kind of evidence there is.

Other scientists checking a paper before a journal publishes it. It filters out some bad work. It does not make a finding true.

A dummy treatment given for comparison. Without one it is very hard to tell a real effect apart from expectation and time passing.

Deciding by chance who gets which treatment, so the two groups are comparable. Studies that skip this are much easier to read the wrong way.

The stages of human testing. Phase 1 checks safety in a small group, phase 2 looks for an effect, and phase 3 tests it against a comparison in a large group.

The two kinds of compounding pharmacy in US law. A 503A pharmacy prepares medicine for one named patient. A 503B outsourcing facility makes larger batches under stricter manufacturing rules.

Prohibited by the World Anti-Doping Agency (WADA); using it can disqualify a competing athlete.

The most serious warning the FDA puts on a drug label, printed inside a black border. It flags a risk considered severe enough to sit above everything else on the label.

The FDA's list of ingredients that compounding pharmacies are allowed to use. A substance can sit under review on it for years without anything being decided either way.

A licensed pharmacy preparing a medicine to order. Being allowed to compound something is not the same as the FDA approving it, and the two get mixed up constantly.

Reviewed by the FDA and cleared for a specific use, in a specific form, at a specific dose. Approval for one use is not approval for another, and approval in another country is not approval here.

Still being tested in clinical trials and not yet approved or legally sold for general use.

A doctor prescribing an approved drug for something other than its approved use. This is legal and common, and it is different from a compound having no approval at all.

A status given to treatments for rare conditions to make them worth developing. It is an incentive, not an approval, and a compound can hold it while being approved for nothing.

The FDA advisory committee that reviews compounding ingredients. It recommends. It does not approve, and the FDA does not have to follow what it says.

No approved dose or use in people. Sold for research and not reviewed by the FDA for safety or quality.

A lab report on a batch of product. It only means something if it names the batch you actually received, comes from an independent lab, and can be checked with that lab.

A lab method that separates out everything in a sample so the amounts can be measured. It shows how much of the main ingredient is there. It does not confirm that the main ingredient is the right molecule.

A lab method that weighs molecules to confirm what they are. HPLC answers how much is in the sample. This answers what it is.

The share of a sample that is the intended compound, usually given as a percentage. A high purity number on the wrong molecule is still the wrong molecule.