A published account of what happened to a single patient. It can flag a real safety signal, but on its own it cannot establish that the compound caused what was observed.

The public registry of clinical trials and the identifier given to each one. A registered trial can be looked up, including whether it was completed or quietly abandoned.

A sponsor’s early public summary of a trial, released before the full data is published. It is the company describing its own result.

Research done in cells or tissue in a dish, outside a living organism. A result in vitro is a starting point, not evidence that something works in a person.

Research done in a living organism. In this market that usually means rodents.

The work done before human trials begin: cell culture and animal studies. This is the stage most peptide marketing draws its claims from.

The first human trials. Small, and focused on safety and how the body handles the compound rather than on whether it works.

Human trials testing whether the compound does anything and at what dose, usually in a few hundred people at most.

Large human trials designed to demonstrate effectiveness against a comparison group. The stage regulators base approvals on.

A study where participants are assigned by chance to receive the compound or a comparison. Randomization is what stops a result being explained by who chose what.