Reference
Glossary
The vocabulary of peptides, GLP-1 medications, and longevity — defined in plain language, with the evidence caveats that matter. A reference, not medical advice.
GLP-1
- GLP-1
- Glucagon-like peptide-1, a gut hormone (incretin) released after eating that boosts insulin, slows stomach emptying, and reduces appetite. The target of semaglutide and related drugs.
- GLP-1 receptor agonist
- A medication that activates the GLP-1 receptor to mimic the natural hormone — lowering blood sugar and appetite. Examples: semaglutide, liraglutide.
- GIP
- Glucose-dependent insulinotropic polypeptide, a second incretin hormone. Tirzepatide activates both GIP and GLP-1 receptors (a 'dual agonist').
- Incretin
- A gut hormone (GLP-1 and GIP) secreted in response to food that stimulates insulin release. 'Incretin mimetics' are drugs that copy this effect.
- Semaglutide
- A GLP-1 receptor agonist sold as Ozempic and Rybelsus (diabetes) and Wegovy (weight management); also widely compounded.
- Tirzepatide
- A dual GIP/GLP-1 receptor agonist sold as Mounjaro (diabetes) and Zepbound (weight management).
- Retatrutide
- An investigational 'triple agonist' targeting GIP, GLP-1, and glucagon receptors, in late-stage obesity trials as of 2026.
- Orforglipron
- An investigational once-daily oral, non-peptide ('small molecule') GLP-1 receptor agonist — notable for not requiring injection or strict fasting like oral semaglutide.
- Cagrilintide
- A long-acting amylin analog studied for weight loss, including in combination with semaglutide (CagriSema).
- MACE
- Major adverse cardiovascular events — a composite trial endpoint (typically cardiovascular death, heart attack, stroke) used to measure a drug's effect on heart risk.
Peptides
- Peptide
- A short chain of amino acids — smaller than a protein — that can act as a signaling molecule. Many 'research peptides' lack human trial data and FDA approval.
- Amino acid
- The building blocks of peptides and proteins. Chains of amino acids fold into the molecules that drive most biology.
- BPC-157
- A synthetic peptide marketed for tissue repair. Evidence is almost entirely preclinical (animal/in-vitro); there are no robust human trials, and it is not an approved drug.
- TB-500 / Thymosin β4
- A peptide fragment marketed for healing. The studied molecule (thymosin β4) has limited human data, mainly in eye disease; injectable 'TB-500' for recovery is untested and WADA-prohibited.
- GHK-Cu
- A copper-binding tripeptide with credible evidence for topical cosmetic skin benefits; systemic/injected use has no human trials.
- Sermorelin
- A growth-hormone-releasing hormone (GHRH) analog historically used to diagnose/treat childhood growth hormone deficiency; now marketed off-label for anti-aging.
- Ipamorelin
- A growth hormone secretagogue peptide marketed to raise GH/IGF-1. Rigorous human efficacy data are minimal, and supply is unregulated 'research-use'.
- CJC-1295
- A long-acting GHRH analog often paired with ipamorelin. Like ipamorelin, it lacks robust human outcome data and is not an approved therapy.
- Tesamorelin
- A GHRH analog (Egrifta) that is FDA-approved — but specifically to reduce excess abdominal fat in HIV-associated lipodystrophy, not for general anti-aging.
- Growth hormone secretagogue
- A compound that prompts the body to release its own growth hormone (e.g., ipamorelin), as opposed to injecting GH directly.
- GHRH
- Growth-hormone-releasing hormone — the natural signal that tells the pituitary to release growth hormone. Sermorelin, CJC-1295, and tesamorelin are GHRH analogs.
- Certificate of Analysis (COA)
- A third-party lab document attesting to a product's identity, purity, and lack of contaminants — a key transparency signal for compounded or research products.
Longevity
- Healthspan
- The portion of life spent in good health, free of chronic disease and disability — distinct from lifespan (total years lived).
- NAD⁺
- Nicotinamide adenine dinucleotide, a coenzyme essential to energy metabolism and DNA repair. Levels are studied in aging; supplements aim to raise it.
- NMN
- Nicotinamide mononucleotide, an NAD⁺ precursor sold as a supplement. Human data show it can raise NAD⁺ markers; longevity benefits are unproven.
- NR (Nicotinamide riboside)
- Another NAD⁺ precursor supplement. Trials show it safely elevates NAD⁺, but evidence for healthspan or disease outcomes is limited.
- Sirtuins
- A family of NAD⁺-dependent enzymes involved in cellular stress response and metabolism, often discussed in aging biology.
- mTOR
- A central nutrient-sensing pathway that governs cell growth. Inhibiting it (e.g., with rapamycin) extends lifespan in animal models.
- Rapamycin
- An mTOR inhibitor (an approved immunosuppressant) studied off-label for longevity. Human evidence is short-term/biomarker-level, not lifespan outcomes.
- Senolytic
- A compound intended to clear 'senescent' (worn-out, non-dividing) cells thought to drive aging. Human evidence is early-stage.
- Autophagy
- The cell's recycling process for clearing damaged components. It is a frequent target of longevity interventions like fasting and rapamycin.
- Taurine
- An amino acid studied for aging. Animal data are promising, but 2025 human work questioned whether circulating taurine reliably declines with age.
General
- Compounded medication
- A drug mixed by a pharmacy for an individual patient. Compounded GLP-1s are not FDA-approved or pre-market-reviewed for safety and efficacy the way branded drugs are.
- 503A / 503B pharmacy
- Sections of U.S. law defining compounding pharmacies: 503A serve individual prescriptions; 503B 'outsourcing facilities' make larger batches under stricter oversight.
- Titration
- Gradually increasing a medication's dose over weeks to build tolerance and limit side effects — standard for GLP-1 drugs.
- Half-life
- The time it takes for half a drug to clear the body. Longer half-lives allow less-frequent dosing (e.g., once-weekly semaglutide).
- Bioavailability
- The fraction of a dose that reaches the bloodstream intact. Oral peptides have low bioavailability, which is why most are injected.
- LegitScript
- A third-party certification service that vets telehealth and pharmacy operators for legal compliance — a trust signal when evaluating providers.