The GLP-1 Dictionary

Core Science & Hormones

GLP-1 (Glucagon-Like Peptide-1): A naturally occurring gut hormone released after you eat. It tells your brain you are full, slows down digestion, and prompts your body to release insulin.
GLP-1 Receptor Agonist: The medical category for drugs (like Ozempic or Wegovy) engineered to mimic your natural GLP-1 hormone, but built to last much longer in your system.
GIP (Glucose-Dependent Insulinotropic Polypeptide): A second gut hormone that works alongside GLP-1 to help control blood sugar and breakdown of fat.
Dual Agonist: A single medication (like Tirzepatide / Zepbound / Mounjaro) that targets two hormone pathways at once—both GLP-1 and GIP—for enhanced weight loss and blood sugar control.
Triple Agonist: A next-generation medication (like Retatrutide ) that targets three separate metabolic pathways at once to boost calorie burning and reduce appetite.
Satiety: The physical feeling of full, satisfied contentment after eating that tells your brain to stop consuming food.

Titration: The process of starting at a very low dose and stepping it up gradually over several weeks or months. This gives your digestive system time to adapt and prevents severe nausea.
Starting Dose: The initial, lowest dose given strictly to help your body adjust to the medicine, rather than to cause major weight loss right away.
Therapeutic Dose: The target dosage level where the medication produces its full clinical results.
Maintenance Dose: The long-term dose you stay on after reaching your goal weight or target health markers to keep your results stable.
Half-Life: The time it takes for your body to process and clear out 50% of the drug from your system. For weekly GLP-1s, this is roughly 5 to 7 days.
Steady State: The point (usually after 4 to 5 weeks on the same dose) where the amount of medicine entering your body equals the amount being eliminated, keeping levels stable in your blood.
Subcutaneous Injection: A small injection given directly into the fatty layer of tissue right under the skin—usually in the stomach, thigh, or upper arm.

Gastric Emptying: The rate at which your stomach empties its food into your small intestine.
Delayed Gastric Emptying: The deliberate slowing down of digestion caused by GLP-1s. Food sits in your stomach longer, making you feel full faster and stay full longer.
Gastroparesis ("Stomach Paralysis"): A complication where stomach emptying slows down too much or stops entirely, causing persistent nausea, vomiting, and stomach pain.
Sulfur Burps: Foul-smelling burps caused when food sits in the stomach longer than usual and begins to ferment, producing hydrogen sulfide gas.
Reflux / Heartburn: Stomach acid backing up into the esophagus, which can happen when a full stomach empties slowly.

Food Noise: The constant, intrusive background thoughts about food—cravings, planning your next meal, or emotional eating urges—even when you are not physically hungry.
Hedonic Hunger: Eating driven by pleasure, reward, or emotion rather than physical need.
Homeostatic Hunger: True physical hunger triggered when your body genuinely needs calories and nutrients.
Anhedonia: A temporary dulling of pleasure responses. Some GLP-1 users notice a decreased interest in alcohol, online shopping, or other habitual behaviors alongside reduced food cravings.

Active Pharmaceutical Ingredient (API): The pure, biologically active chemical component in a drug that makes it work (e.g., pure Semaglutide or Tirzepatide).
Compounding Pharmacy: A specialized pharmacy licensed to mix or customize medication ingredients for individual patients.
503A Pharmacy: A state-licensed pharmacy that prepares custom, patient-specific prescriptions.
503B Outsourcing Facility: An FDA-registered facility that can manufacture compounded medications in larger batches for clinics and providers.
Off-Label Use: When a doctor legally prescribes an FDA-approved drug for a condition other than its primary official approval (e.g., prescribing Ozempic for weight loss instead of type 2 diabetes).

Lean Body Mass: Total body weight minus body fat, which includes muscles, bones, organs, and fluids.
Muscle Wasting: The unwanted loss of muscle tissue during rapid weight loss, which can be minimized by eating adequate protein and doing strength training.
Rebound Weight Gain: Weight regained after stopping GLP-1 treatment, caused by the return of baseline hunger signals and original digestion speeds.
Ozempic Face: A popular term for facial hollows or loose skin caused by rapid fat loss in the face during significant overall weight loss.