Glossary
- 503A compounding
- The US legal framework allowing licensed pharmacies to compound individualized prescriptions, limited to certain eligible bulk substances.
- Double-blind
- Neither participants nor researchers know who receives the treatment, which reduces bias.
- GHRH
- Growth hormone-releasing hormone, which signals the pituitary to release growth hormone.
- GLP-1
- Glucagon-like peptide 1, a gut hormone that raises insulin when glucose is high and reduces appetite.
- Half-life
- How long it takes the body to clear half of a substance.
- IGF-1
- Insulin-like growth factor 1, a hormone produced largely in response to growth hormone.
- Peptide
- A short chain of amino acids. Insulin and semaglutide are peptides; so are many supplements sold with far less evidence.
- Preclinical
- Research in cells or animals, before human testing. Many promising preclinical results fail in humans.
- Randomized controlled trial (RCT)
- A study that randomly assigns participants to treatment or a comparison group (often placebo). The strongest design for showing a treatment works.
- Research chemical
- A marketing term for products sold labelled "not for human consumption". It carries no legal approval for human use.
- Retrospective study
- Looks back at past records or experiences instead of following patients forward. Prone to bias and cannot prove cause and effect.
- Surrogate marker
- A lab measurement standing in for a real health outcome, such as hormone levels instead of muscle gain.
- Systematic review
- A structured search and summary of all studies on a question, following predefined criteria.
- WADA
- World Anti-Doping Agency, which maintains the Prohibited List used in tested sports.