Receptor & Mechanism Terms
GLP-1 (Glucagon-Like Peptide-1)
A hormone produced in the gut after eating. It stimulates insulin release, suppresses glucagon, slows gastric emptying, and reduces appetite via brain receptors. GLP-1 is the mechanism behind semaglutide (Ozempic/Wegovy), tirzepatide (Mounjaro), and Retatrutide.
GIP (Glucose-Dependent Insulinotropic Polypeptide)
An incretin hormone produced in the small intestine. Activating GIP receptors boosts insulin secretion, reduces adipose tissue inflammation, improves fat cell sensitivity, and may enhance bone metabolism. Added to GLP-1 in tirzepatide; also present in Retatrutide.
Glucagon Receptor
The receptor activated by glucagon, a hormone that raises blood sugar and mobilizes energy stores. In Retatrutide, glucagon receptor activation increases resting energy expenditure, stimulates lipolysis (fat breakdown), and promotes thermogenesis — the mechanism that differentiates Retatrutide from all predecessors.
Triple Agonist
A compound that simultaneously activates three different receptors. Retatrutide is the first triple agonist targeting GIP, GLP-1, and glucagon receptors. The "triple" in "Triple G" or "Triple Agonist" refers to these three receptor targets.
Incretin
A class of metabolic hormones released by the gut in response to food intake that stimulate insulin secretion. GIP and GLP-1 are both incretin hormones. Incretin-based therapies (including all GLP-1 agonists) exploit this signaling pathway for metabolic research.
Agonist
A molecule that binds to a receptor and activates it, producing a biological response. The opposite of an antagonist (which blocks a receptor). All GLP-1 drugs — semaglutide, tirzepatide, Retatrutide — are receptor agonists.
Lipolysis
The breakdown of stored fat (triglycerides) into free fatty acids and glycerol, which can then be used for energy. The glucagon receptor component of Retatrutide directly promotes lipolysis — a key reason Retatrutide burns fat more aggressively than GLP-1-only compounds.
Thermogenesis
The production of heat in the body through metabolic processes, which consumes calories. Glucagon receptor agonism in Retatrutide promotes thermogenesis — increasing the number of calories burned at rest even without changes in physical activity.
Peptide Science Terms
Lyophilization (Freeze-Drying)
The standard preservation method for research peptides. The peptide is frozen and then water is removed via sublimation under vacuum, leaving a stable dry powder. Lyophilized peptides are stable for months to years when stored correctly. All QSC peptides are lyophilized.
Reconstitution
Dissolving a lyophilized (dry) peptide into a liquid solution for use. For Retatrutide, bacteriostatic water (BAC water) is the standard reconstitution vehicle. The resulting solution must be refrigerated and used within 28–30 days.
Bacteriostatic Water (BAC Water)
Sterile water containing 0.9% benzyl alcohol, used to reconstitute peptides. The benzyl alcohol acts as a preservative that inhibits bacterial growth, extending the usable shelf life of the reconstituted peptide solution to approximately 28–30 days when refrigerated.
HPLC (High-Performance Liquid Chromatography)
The analytical technique used to measure peptide purity. Separates mixture components by their interaction with a stationary phase under high pressure, then quantifies each component using a UV detector. A single dominant peak in the HPLC chromatogram indicates high purity. The standard for COA purity reporting.
Mass Spectrometry (MS)
Analytical technique that measures the mass-to-charge ratio of ionized molecules. Used to confirm peptide identity by matching the detected molecular weight against the theoretical mass. For Retatrutide, the expected MW is 4731.33 g/mol. MS is the only way to confirm correct identity and distinguish Retatrutide from cheaper peptides that might be substituted.
COA (Certificate of Analysis)
Documentation proving that a specific batch of peptide meets its claimed specifications. Should include: batch number, purity % by HPLC, molecular weight by MS, testing laboratory, and testing date. Every QSC order includes a batch-specific COA.
Fatty Acid Conjugation
A chemical modification where a fatty acid chain is attached to a peptide. Retatrutide has a C20 fatty diacid conjugated to a lysine residue — this modification allows Retatrutide to bind to albumin in the bloodstream, dramatically extending its half-life from hours (native GIP/GLP-1) to approximately 7 days, enabling once-weekly dosing.
Subcutaneous Injection
Administration method where a substance is injected into the subcutaneous tissue — the fat layer just beneath the skin, typically in the abdomen, thigh, or upper arm. All GLP-1 class peptides, including Retatrutide, are administered subcutaneously. Subcutaneous injection allows slower absorption compared to intravenous injection, producing a more gradual concentration profile.
Clinical Trial Terms
Phase 2 Trial
A clinical trial stage that studies a drug in a larger group of people (hundreds) to evaluate efficacy and safety more broadly, and to identify optimal dosing. Retatrutide's landmark Phase 2 trial (NEJM, June 2023, n=338) established its efficacy profile and produced the 24.2% weight loss result.
Phase 3 Trial
The large-scale confirmatory clinical trial stage (thousands of participants) required for regulatory approval. Retatrutide is currently in Phase 3 trials for obesity. Phase 3 results are expected to determine whether Retatrutide can be approved by the FDA and other regulatory agencies as a commercial therapeutic.
Dose Escalation
A protocol where participants start at a low dose that is gradually increased over time. Used with GLP-1 class peptides to allow the body to adapt to the drug's effects and reduce GI side effects. The Retatrutide Phase 2 protocol used a 24-week escalation phase before reaching the target maintenance dose.
Placebo-Controlled
A trial design where some participants receive the active drug and some receive an inactive placebo (sugar water or saline). Neither participants nor researchers know who received which (double-blind). The Retatrutide Phase 2 trial was randomized, double-blind, and placebo-controlled — the gold standard for evidence quality.
Mean Body Weight Reduction
The average percentage of starting body weight lost across all participants in a treatment group. Retatrutide achieved 24.2% mean body weight reduction at the highest dose (12 mg/week) over 48 weeks — the highest ever recorded in a pharmaceutical clinical trial without surgery.
NASH / NAFLD
Non-alcoholic steatohepatitis (NASH) and non-alcoholic fatty liver disease (NAFLD) — conditions characterized by excess fat accumulation in the liver without significant alcohol consumption. Retatrutide's glucagon receptor component drives direct hepatic fat mobilization, reducing liver fat by 46% in the Phase 2 metabolic syndrome subgroup. This positions Retatrutide as a potential research tool for NASH/NAFLD as well as obesity.
Supplier & Quality Terms
QSC Peptides / QSC Reta / QSC RT10
QSC Peptides (qscpeptide.com) is the research peptide supplier powering ShopReta.com. "QSC Reta" refers to QSC's Retatrutide product line. "QSC RT10" is the community shorthand referencing QSC's 10mg Retatrutide vial — the most common single-vial research configuration.
Research Grade
Peptides sold for laboratory and scientific research purposes, verified for identity and purity by analytical testing. Not the same as pharmaceutical grade (which requires additional manufacturing standards for human drug use). All QSC products are research grade with ≥99% purity verification.
Domestic Warehouse
Physical peptide inventory held in a warehouse located within the researcher's country. QSC maintains domestic warehouses in USA, EU, UK, Australia, and Canada — enabling domestic shipping with no customs exposure, faster delivery, and lower risk versus international shipments.
KYC (Know Your Customer)
Legal identity verification requirements applied to financial services, including cryptocurrency exchanges. When you sign up for Coinbase, Kraken, or Binance, you'll be asked to verify your identity with a government ID. This is a legal requirement, not a choice, and is the same process as opening a bank account.
Related Compounds
Semaglutide (Ozempic / Wegovy)
A single GLP-1 receptor agonist developed by Novo Nordisk. FDA-approved for Type 2 diabetes (Ozempic) and obesity (Wegovy). Produces ~14.9% weight loss at 68 weeks. The predecessor that Retatrutide surpasses by adding GIP and glucagon receptor activation.
Tirzepatide (Mounjaro / Zepbound)
A dual GIP/GLP-1 receptor agonist developed by Eli Lilly. FDA-approved for Type 2 diabetes (Mounjaro) and obesity (Zepbound). Produces ~20.9% weight loss at 72 weeks. The generation between semaglutide and Retatrutide — Retatrutide adds glucagon receptor activation to this dual mechanism.
Cagrilintide
A long-acting amylin analogue (amylin receptor agonist) developed by Novo Nordisk. Amylin is a pancreatic hormone that reduces food intake via separate pathways from GLP-1/GIP/glucagon. QSC offers a Retatrutide + Cagrilintide blend (10mg/10-vial kit, $310) that combines all four receptor targets for maximally comprehensive metabolic research.
Survodutide
A dual GLP-1/glucagon receptor agonist developed by Boehringer Ingelheim. Also available from QSC Peptides. Similar to Retatrutide in having glucagon activation, but without the GIP component. Useful as a comparison compound in multi-pathway research designs.
LY3437943
Eli Lilly's internal development code for Retatrutide. This is the identifier you'll find in scientific papers, PubChem, and regulatory documents. CAS number: 2381089-83-2. All three names — LY3437943, Retatrutide, and Reta — refer to the same molecule.