Short definitions first. Scientific wording second.
An agonist turns a receptor on, or turns it on in a way that copies the natural signal.
An antagonist blocks a receptor so the usual key has a harder time working.
Bioavailability is how much of a substance actually reaches the bloodstream in an active form after you take it.
Clinical evidence means information from studies in people. It can still be weak, biased, or mixed. 'Clinical' does not automatically mean 'proven' or 'approved'.
A clinical trial is a research study in people. Trials have phases, rules, and limits. Being in a trial is not the same as a treatment being approved.
The European Medicines Agency is the European Union body involved in evaluating many medicines for use in EU countries.
The U.S. Food and Drug Administration is the federal agency that reviews many medicines for safety and effectiveness before they can be marketed for specific uses.
Half-life is how long it takes for the amount of a substance in the body to fall by half. A longer half-life often means less frequent dosing in approved medicines — that is pharmacology, not a reason to self-dose.
In vitro means 'in glass' — experiments in dishes, tubes, or other lab systems, not in a living body.
In vivo means in a living organism — often mice or rats in peptide research.
Intramuscular means into a muscle. This is a route category, not a how-to.
Intravenous means into a vein, so the substance enters the bloodstream directly. This is not instructions for use.
A peptide is a short chain of amino acids — the same building blocks used to make proteins, but usually much smaller than a full protein.
Pharmacodynamics is what a substance does to the body — the actual biological effect.
Pharmacokinetics is what the body does to a substance: absorb, distribute, break down, and clear it.
A placebo looks like the treatment but does not contain the active medicine. It helps researchers see whether the real treatment does more than expectation and usual care.
Preclinical research happens before adequate human trials — usually in cells or animals. Promising animal data often fail to repeat in people.
An RCT randomly assigns people to different groups (for example medicine vs placebo) so the comparison is fairer.
A receptor is a lock on a cell. A peptide or drug can act like a key that fits that lock and changes what the cell does.
Reconstitution means adding a sterile liquid to a freeze-dried powder so it becomes a solution. Approved medicines have official instructions. The calculator page has general lab notes; it is not a personal mixing protocol.
A research chemical is a substance sold for laboratory research, not as an approved medicine. Quality, identity, and safety are often uncertain.
Subcutaneous means under the skin. Many peptide medicines are given this way because peptides often break down if swallowed. This glossary term is not an injection lesson.