Ozempic, Wegovy, Mounjaro, Saxenda: How the GLP-1 Options Differ

Patients — and clinics fielding their questions — increasingly need a clear map of the GLP-1 landscape. The brand names are used loosely, several share an active ingredient, and the differences that matter are not always obvious. This is an orientation, not prescribing guidance: these are prescription medicines, initiated and supervised by an appropriate prescriber.

What "GLP-1" Means

GLP-1 (glucagon-like peptide-1) is a hormone the gut releases after eating. It signals fullness to the brain, slows stomach emptying and helps regulate blood sugar. GLP-1 receptor agonists are medicines that mimic this signal — reducing appetite and food intake. Some newer agents add a second mechanism (GIP) for a stronger effect.

The Main Options

• Semaglutide — sold as Ozempic (licensed for type 2 diabetes) and Wegovy (licensed for weight management). Same active ingredient, different branding and indication. A once-weekly injection. Trials place average weight loss in the region of 15%.
• Tirzepatide — sold as Mounjaro. A dual GIP/GLP-1 agonist, also once weekly. The added mechanism is associated with a higher average weight loss, in the region of 21% in trials.
• Liraglutide — sold as Saxenda. An earlier GLP-1 agonist given as a daily injection, with a more modest average result than the weekly agents.
• Dulaglutide (Trulicity) — a once-weekly GLP-1 agonist used primarily for type 2 diabetes rather than as a dedicated weight-management product.

The Practical Differences

Three variables usually matter most to patients:

• Dosing rhythm — weekly (semaglutide, tirzepatide, dulaglutide) versus daily (liraglutide). Convenience often drives preference.
• Expected magnitude — broadly, tirzepatide > semaglutide > liraglutide on average, though individual response varies widely.
• Titration — all are started low and increased gradually to manage gastrointestinal side-effects such as nausea; the schedule differs between products.

Side-Effects and Supervision

The common side-effects are gastrointestinal — nausea, reduced appetite, occasional constipation or reflux — and usually ease as the body adjusts. Because these are prescription medicines with contraindications and monitoring needs, selection and dose are decisions for the prescribing clinician, not a catalogue.

Where Aesthetics Comes In

Whichever agent is used, substantial weight loss brings the facial and body volume changes discussed in our guide to "Ozempic face". Planning for that alongside the weight-loss journey — rather than as an afterthought — makes for a better overall outcome.

The Takeaway

The GLP-1 field comes down to a few actives (semaglutide, tirzepatide, liraglutide) sold under familiar brand names, differing mainly in mechanism, dosing rhythm and average effect. All are prescription medicines requiring supervision. For the aesthetic side of the journey, see restoring volume after weight loss and what's new in GLP-1 for 2026.