Semaglutide: How It Works, Dosing, and What to Expect

What semaglutide is

Semaglutide is a GLP-1 receptor agonist. GLP-1 is an incretin hormone your gut releases after eating. Semaglutide mimics and prolongs that signal: it quiets appetite through receptors in the hypothalamus and brainstem, slows how fast your stomach empties, and improves glucose-dependent insulin release. It is the active molecule in Ozempic and Wegovy (and Rybelsus, the oral form).

How it drives weight loss

The dominant effect for weight management is appetite reduction. Patients describe earlier fullness and a drop in "food noise," the constant background pull toward eating. In its pivotal weight-loss trial, semaglutide at 2.4 mg weekly produced roughly 15% mean body-weight reduction at 68 weeks in adults without diabetes. Cardiovascular benefit is real too: the SELECT trial showed a 20% reduction in major cardiovascular events, independent of how much weight was lost.

Standard dosing and titration schedule

Semaglutide for weight management is a once-weekly subcutaneous injection. It starts low and steps up roughly every 4 weeks to limit side effects. The standard Wegovy titration is:

• Weeks 1-4: 0.25 mg once weekly
• Weeks 5-8: 0.5 mg once weekly
• Weeks 9-12: 1.0 mg once weekly
• Weeks 13-16: 1.7 mg once weekly
• Week 17 onward: 2.4 mg once weekly (maintenance)

This schedule is a starting framework, not a rule. The right dose is the lowest one that produces steady progress without intolerable side effects. Your provider may hold you at a lower step longer if side effects are significant, or stay below 2.4 mg if a lower dose is working.

Side effects

The common side effects come from the slowed gut: nausea, constipation, diarrhea, and reflux. They are dose-dependent, worst in the first weeks after each increase, and usually settle as your body adapts. Pace of titration matters more than most people realize, going up too fast is where the misery comes from. Uncommon but serious risks include gallbladder issues and pancreatitis (report severe, persistent abdominal pain immediately). Semaglutide carries a boxed warning regarding thyroid C-cell tumors based on rodent data and is not appropriate with a personal or family history of medullary thyroid carcinoma or MEN2.

Compounded vs brand-name

Brand-name semaglutide is expensive without insurance coverage, and coverage for weight loss is inconsistent. Compounded semaglutide, prescribed when clinically appropriate, is typically billed by the pharmacy at cost and is generally the more affordable option. The compounding landscape shifts with FDA shortage status and regulation, so a responsible prescriber tracks that and tells you when something changes. Compounded semaglutide usually runs less per month than compounded tirzepatide because it is the simpler molecule.

The KAYU approach

Every GLP-1 protocol at KAYU starts with labs, not a prescription: fasting insulin, HOMA-IR, HbA1c, full thyroid, ApoB, liver and kidney markers, and a complete blood count. Your provider reads it as a system, because appetite suppression will not fix untreated thyroid dysfunction or a hormone deficiency on its own. The protocol includes a muscle-preservation plan (rapid weight loss strips lean mass without protein and resistance training) and a defined maintenance and off-ramp strategy.