Pathways compared

Gastric sleeve (sleeve gastrectomy)

Sleeve gastrectomy is the most-performed bariatric procedure in Australia — about 60–70% of all primary bariatric operations. The surgeon removes around 75–80% of the stomach, creating a narrow tube ("sleeve") that restricts food volume and reduces ghrelin (the hunger hormone). Average weight loss is 25–30% of body weight at 12–24 months, with the strongest cohort outcomes at high-volume centres.

Wegovy vs Mounjaro

The two leading GLP-1 weight-loss medications available in Australia: Wegovy (semaglutide, by Novo Nordisk) and Mounjaro (tirzepatide, by Eli Lilly). Both are once-weekly injections. Both are TGA-approved for obesity (BMI 30+, or BMI 27+ with weight-related health conditions). Both cost $400–$600/month privately. Average weight loss differs significantly: Wegovy 15% body weight over 68 weeks in trials; Mounjaro 21% over 72 weeks — currently a TGA-approved weight-management medicine available.

Bariatric surgery vs GLP-1 medication

The two effective options for adults with BMI 30+ in Australia who have not achieved sustained weight loss through diet + exercise alone. **Bariatric surgery** (sleeve gastrectomy or gastric bypass): permanent, 25–30% body weight loss, $8–25k cost. **GLP-1 medication** (Wegovy or Mounjaro): ongoing weekly injection, 15–21% body weight loss while medication continues, $5–7k/year. The right choice depends on BMI, comorbidities, age, lifestyle and willingness to commit to a permanent procedure versus an ongoing treatment.