Glossary

Last reviewed: September 2026

AAS

Anabolic-androgenic steroids

Synthetic derivatives of testosterone. The class studied in most of the long-running human literature on performance-enhancing drug harms.

Ancillary

A compound taken alongside another to manage its side effects rather than for a performance effect of its own — for example a SERM or aromatase inhibitor used during or after androgen use.

Bacteriostatic water

Sterile water containing a preservative, sold for reconstituting freeze-dried peptides. Vendors usually treat it as non-returnable once opened.

Bloodwork

Blood panel

A set of laboratory blood tests used to monitor markers such as lipids, liver enzymes, haematocrit and hormone levels. Interpreting results requires clinical context — training and dehydration alone can move several markers.

COA

Certificate of analysis

A laboratory document stating the identity and purity of a specific batch. A COA is only as meaningful as the lab that issued it, the batch number it names, and whether that batch is the one you received.

Cloaking

Showing search engines different content than human visitors see. It is a search-engine policy violation and, on a commerce site, a signal that public claims may not be what buyers experience.

Evidence grade

Our rating of how strong the published human evidence is for a compound: Moderate, Limited, Very limited, or Preclinical only. It rates the literature, not the compound's safety or desirability.

HPLC

High-performance liquid chromatography

A laboratory technique used to separate and quantify the components of a sample. In this context it is the method most often cited to support a purity percentage.

HPTA

Hypothalamic-pituitary-testicular axis

The hormonal feedback loop that regulates natural testosterone production. Exogenous androgens suppress it; recovery time after use varies widely between individuals.

hCG

Human chorionic gonadotropin

A hormone used clinically in fertility medicine and, outside medical supervision, in attempts to restart suppressed testicular function.

IGF-1

Insulin-like growth factor 1

A growth factor largely produced in the liver in response to growth hormone. Often measured as a proxy for growth-hormone activity.

LC-MS

Liquid chromatography–mass spectrometry

An analytical method used to confirm the identity of a compound, often reported alongside HPLC purity figures.

PCT

Post-cycle therapy

A term used in community settings for compounds taken after androgen use in an attempt to restore natural hormone production. The practice is far less standardised than the name implies and is not a clinical protocol.

PED

Performance-enhancing drug

Any substance used to improve physical performance or appearance. As used on this site it covers androgens, SARMs, peptides, stimulants and related research chemicals.

Peptide

A short chain of amino acids. In this market the term covers a wide range of compounds with very different evidence bases, from well-studied therapeutics to substances with no human data at all.

Preclinical

Research conducted in cells or animals rather than people. Preclinical results indicate a mechanism worth studying; they do not establish that something works or is safe in humans.

RCT

Randomised controlled trial

A study in which participants are randomly assigned to treatment or control. The strongest common design for establishing whether an effect is caused by the intervention.

Research-use-only

RUO

A labelling convention stating a product is not for human consumption. It describes how a product is sold, not what it contains or how safe it is.

SARM

Selective androgen receptor modulator

A compound designed to act on androgen receptors with more tissue selectivity than testosterone. Most SARMs have no completed human safety programme.

SERM

Selective estrogen receptor modulator

A compound that blocks or activates estrogen receptors depending on the tissue. Used clinically in breast cancer and fertility medicine, and in community settings as an ancillary.

Suppression

The reduction of natural hormone production caused by taking an exogenous hormone or hormone-like compound. Degree and duration vary by compound, dose and individual.

Supraphysiological

Above the range the body produces naturally. Much of the recreational-use literature involves supraphysiological doses, which is why therapeutic trial results often do not transfer.

Third-party tested

Tested by a laboratory independent of the seller. The phrase carries weight only when the laboratory is named and the result is traceable to a batch.

Definitions describe how each term is used in the literature and in this market. They are educational and are not medical advice.