GLP-1 Medications: A Complete Guide
Summary: A working reference for GLP-1 receptor agonists. We cover what each medication does, what the trials actually showed, what the side effects look like in practice, and what it costs to get treatment. Every claim links to a primary source.
This content is for informational purposes only and is not medical advice. Always consult a qualified healthcare provider before starting, changing, or stopping any medication.
GLP-1 receptor agonists are the most consequential change in metabolic medicine in a generation. In about a decade they have moved from a niche second-line diabetes drug to one of the most widely prescribed medications in the United States. Semaglutide and tirzepatide produce double-digit body weight reductions in clinical trials, drop A1c by two percentage points or more in type 2 diabetes, and reduce major cardiovascular events in people with established disease. They also slow gastric emptying enough to cause real nausea, cost north of a thousand dollars a month at brand pricing, and carry warnings that matter.
This site exists to make those tradeoffs legible. Each article anchors to FDA prescribing information, trial papers in journals like the New England Journal of Medicine and JAMA, and recognized clinical references. When something is genuinely uncertain, including long-term safety beyond five years and how durably weight loss holds after stopping, we say so.
Start here
What is GLP-1?
The gut hormone behind every drug in the class, what it does in your body, and why drugmakers had to redesign it.
Semaglutide
The molecule sold as Ozempic, Wegovy, and Rybelsus. Indications, dosing, STEP and SUSTAIN trial results, and the full safety profile.
Tirzepatide
Mounjaro and Zepbound. The dual GIP/GLP-1 agonist that produced the largest weight loss numbers in any obesity trial to date.
Side Effects & Risks
What is common and manageable, what is rare but serious, and the boxed warnings every patient should know about.
Cost, access, and the compounded question
Cost & Access
Real cash prices, what insurance does and does not cover, manufacturer direct programs, and how to think about lower-cost paths.
Compounded vs Brand
What changed when semaglutide and tirzepatide came off the FDA shortage list, what is still legal, and how to vet a compounding pharmacy.
Dosage Guide
Starting doses, titration intervals, and maximum doses for every approved GLP-1 medication, with charts you can scan.
Injection Guide
Step by step for pens and for vial-and-syringe, where to inject, how to rotate sites, and how to handle missed doses.
Living with a GLP-1
Diet & Nutrition
What to eat when appetite drops, foods that worsen nausea, protein targets, hydration, and how alcohol behaves on the drug.
Exercise & Lifestyle
Resistance training is the lever for keeping muscle. A practical weekly template plus how to fuel training when appetite is low.
Benefits & Results
Weight loss percentages, A1c reductions, cardiovascular outcomes from SELECT and SUSTAIN-6, kidney protection from FLOW, and emerging uses.
FAQ
Quick answers to the questions people actually ask. How fast does it work, what if you miss a dose, what happens when you stop.
Other medications and reference
Liraglutide
Saxenda and Victoza. The older daily injection that made GLP-1 weight management possible. Now facing generic competition.
Retatrutide
Lilly's investigational triple agonist. Phase 2 produced about 24 percent weight loss. Phase 3 is reading out.
How GLP-1 Works
The four-part mechanism behind every drug in the class: insulin, glucagon, gastric emptying, and appetite signaling.
Glossary
Plain-language definitions for the vocabulary that comes up across the site and in the trial papers.
How we write
Every article anchors to primary sources. Numbers come from trial papers, doses from FDA labels, warnings from the FDA's safety communications. Where the evidence is mixed or thin, we name what is uncertain instead of papering over it. The full editorial standards are on the About page, and our commercial relationships are on the Disclaimer page.