Glossary
The vocabulary,
in plain language.
Terms you will meet on this site and in the research literature, explained without jargon. Education only; definitions are general and not tailored to any individual.
- 01Peptide
- A short chain of amino acids — the same building blocks as proteins, but shorter. The body makes many peptides naturally as signalling molecules. Research peptides are synthetic copies or modifications of these.
- 02Preclinical
- Research done before a compound is studied in people: laboratory work on cells and tissue, and studies in animals. A preclinical finding is a starting point, not evidence of what happens in humans.
- 03Clinical trial
- A study in human participants, usually run in phases from small safety studies to large controlled trials. Only clinical trials can show whether something works and is safe in people.
- 04Peer-reviewed
- Published in a journal where other qualified researchers checked the work before publication. Not a guarantee of correctness, but a meaningful filter compared with blogs, forums, or vendor pages.
- 05Mechanism of action
- How a compound is thought to produce an effect at the biological level — which receptor it binds, which pathway it influences. A described mechanism is not proof of a clinical benefit.
- 06Secretagogue
- A substance that prompts the body to release another substance. Growth-hormone secretagogues, for example, are studied for their effect on the body’s own growth-hormone release rather than supplying the hormone directly.
- 07GLP-1
- Glucagon-like peptide-1, a hormone involved in appetite and blood-sugar regulation. GLP-1 receptor agonists are a class of medicines studied and approved for specific metabolic uses.
- 08Bioidentical
- A hormone that is chemically identical to one the body produces. “Bioidentical” describes the molecule, not how it is manufactured or whether it is appropriate for a particular person.
- 09Off-label
- Use of an approved medicine for a purpose other than the one it was approved for. Legal for a licensed provider to consider in some jurisdictions, but the evidence for the off-label use may be limited.
- 10FDA-approved
- Reviewed and authorised by the U.S. Food and Drug Administration for a specific use, dose, and population. Many peptides discussed in research are not FDA-approved drugs, or are approved only for unrelated uses.
- 11Compounded
- Prepared by a pharmacy to a provider’s specification rather than mass-produced. Compounded preparations are not FDA-approved products and are subject to different oversight.
- 12Contraindication
- A condition, medication, or circumstance that makes a treatment inadvisable for a person. Identifying contraindications is one of the main purposes of provider review.
- 13Intake
- The confidential questionnaire a provider uses to understand your history, medications, and goals before deciding whether any conversation about treatment is appropriate.
- 14Provider review
- A licensed clinician reading your intake and applying their judgment to it. The outcome may be a conversation, a request for more information, or a decision that something is not appropriate for you.
- 15Placebo-controlled
- A trial design where some participants receive an inactive comparison. It is how researchers separate a real effect from expectation. Studies without a control group are much weaker evidence.
- 16Half-life
- How long it takes the body to clear half of a substance. It is one factor in how often something is given, and is determined by a provider — never by a website.
- 17Regenerative medicine
- A broad research field focused on repair of tissue and function. Many peptide topics are discussed under this umbrella; the label describes a field of study, not an established result.
- 18Telehealth
- Care delivered remotely, by video, phone, or a secure portal. Whether a provider can offer it depends on where you and they are located and on their licensing.
- 19503A pharmacy
- A state-licensed compounding pharmacy that prepares medicines for individual patients under a prescription. It may only use ingredients that are approved, on an FDA list, or in Category 1 for evaluation.
- 20503B outsourcing facility
- An FDA-registered facility that compounds larger batches under stricter manufacturing rules. Different regulation from a 503A pharmacy.
- 21Category 2 (bulk substance)
- An FDA designation for a compounding ingredient under evaluation where the agency has identified significant safety concerns. Compounders are expected not to use it while the designation stands. Several popular peptides were placed here in 2023.
- 22Research use only (RUO)
- A label meaning a product is sold for laboratory research and not for human use. It is not tested for sterility, purity or dose accuracy for injection.
- 23WADA prohibited list
- The World Anti-Doping Agency's list of substances banned in sport. Includes growth-hormone secretagogues, BPC-157, TB-500, testosterone and DHEA.
- 24Investigational drug
- A compound being tested in registered clinical trials and not yet approved. Retatrutide and cagrilintide are current examples.
- 25Autologous
- Derived from the patient's own body — PRP is the common example. Regulated differently from manufactured drugs.
- 26Label
- The FDA-approved prescribing information for a medicine: indication, dosing, contraindications and warnings. "Off-label" means use outside it.
