weightloss.com.au
weightloss.com.au
Orlistat logoOrlistat
vs
Mounjaro logoMounjaro

Orlistat vs Mounjaro

Orlistat is the most accessible weight loss medication in Australia, available over-the-counter at $50-80/month with ~3-5% weight loss. Mounjaro is the most effective, producing ~21% weight loss as a weekly injection at $395+/month. They work by completely different mechanisms: Orlistat blocks fat absorption in the gut while Mounjaro targets GIP and GLP-1 receptors.

Orlistat: ~3-5% avg. loss
Mounjaro: ~21% avg. loss
Orlistat cost: $50-80 (OTC available)
Mounjaro cost: From $395 private

Compare Orlistat vs Mounjaro at a Glance

 OrlistatMounjaro
Drug classLipase inhibitorDual GIP/GLP-1 receptor agonist
How takenOral capsule with meals (up to 3x daily)Weekly injection
Avg. weight loss~3-5%~21%
First approved1999 (FDA), 2000 (TGA)2022 (FDA), 2023 (TGA)
AU cost/month$50-80 (OTC available)From $395 private
PBS statusNoNo
Prescription needed?OTC (60mg) / Rx (120mg)Yes
AU supply statusWidely availableStable

Compare Orlistat vs Mounjaro Cost in Australia

Orlistat: $50-80 (OTC available)

Mounjaro: From $395 private

Compare Orlistat vs Mounjaro Weight Loss Efficacy

Orlistat Clinical Trials

XENDOS

5.8kg loss vs 3kg placebo

4 yearsn=3,304

Multiple Phase 3

~3-5% body weight reduction

12-52 weeks

Mounjaro Clinical Trials

SURMOUNT-1

20.9% weight loss (15mg)

72 weeksn=2,539

SURMOUNT-2

15.7% weight loss (diabetes pop.)

72 weeks

SURMOUNT-3

25.3% weight loss (with lifestyle intervention)

88 weeks

SURMOUNT-OSA

Significant improvement in sleep apnoea

52 weeks

Clinical trial data at highest approved doses. Individual results vary.

Compare Orlistat vs Mounjaro Side Effects

Orlistat

Very common

  • Oily/fatty stools
  • Oily spotting
  • Increased flatulence
  • Faecal urgency

Common

  • Abdominal discomfort
  • Liquid stools
  • Frequent bowel movements
  • Headache

Serious (rare)

  • Liver injury (very rare)
  • Kidney stones (rare)
  • Reduced fat-soluble vitamin absorption (A,D,E,K)
  • May affect absorption of some medications

Mounjaro

Very common

  • Nausea (up to 33%)
  • Diarrhoea (up to 23%)
  • Decreased appetite

Common

  • Vomiting
  • Constipation
  • Abdominal pain
  • Dyspepsia
  • Injection site reactions

Serious (rare)

  • Pancreatitis
  • Hypoglycaemia (with insulin)
  • Gallbladder disease
  • Thyroid tumour risk (animal data)
  • May reduce effectiveness of oral contraceptives

Compare How Orlistat and Mounjaro Work

Orlistat

Lipase inhibitor

Completely different mechanism to GLP-1 drugs. Inhibits gastric and pancreatic lipase enzymes, preventing approximately 30% of dietary fat from being absorbed. Unabsorbed fat passes through the digestive system. Does not affect appetite or the brain. Most effective with a reduced-fat diet.

Mounjaro

Dual GIP/GLP-1 receptor agonist

First dual-agonist: targets both GIP and GLP-1 receptors simultaneously. This dual mechanism produces greater weight loss than GLP-1-only drugs. Reduces appetite, slows gastric emptying, improves insulin sensitivity, with additional metabolic benefits through the GIP pathway.

Compare Orlistat vs Mounjaro Dosing Schedule

Orlistat

Oral capsule with meals (up to 3x daily)

DosePeriodNote
60mg OTCWith each mealUp to 3 capsules/day
120mg RxWith each mealUp to 3 capsules/day

Mounjaro

Weekly injection

DosePeriodNote
2.5mgWeeks 1-4Starting dose
5mgWeeks 5-8Escalation / maintenance
7.5mgWeeks 9-12Escalation
10mgWeeks 13-16Escalation / maintenance
12.5mgWeeks 17-20Escalation
15mgWeek 21+Maximum maintenance

Compare Orlistat vs Mounjaro Australian Regulatory Status

Orlistat

TGA StatusRegistered (OTC and prescription strengths)
PBS ListedNo PBS listing
OTC Availability60mg available without prescription at pharmacies
Key AdvantageNo needles, no Rx for lower dose, cheapest option, longest safety record
LimitationModest weight loss vs GLP-1 drugs; GI side effects related to fat intake

Mounjaro

TGA StatusRegistered on ARTG for T2D, weight management, and OSA
PBS ListedNo PBS listing for any indication
Zepbound BrandUS/UK weight loss brand name not used in Australia
Supply StatusAvailability improving; no critical shortage reported
Oral VersionEli Lilly's oral GLP-1 (orforglipron) expected FDA decision mid-2026; not yet in AU

Full Orlistat profile

View Orlistat Details

Full Mounjaro profile

View Mounjaro Details

Compare Other Medications

Orlistat vs Ozempic

~3-5% vs ~15% avg. weight loss

Orlistat vs Wegovy

~3-5% vs ~15-17% avg. weight loss

Contrave vs Orlistat

~5-8% vs ~3-5% avg. weight loss

Orlistat vs Saxenda

~3-5% vs ~8% avg. weight loss

Mounjaro vs Ozempic

~21% vs ~15% avg. weight loss

Wegovy vs Mounjaro

~15-17% vs ~21% avg. weight loss

View all weight loss medications

This website is for informational and research purposes only. We are not medical professionals and nothing on this page constitutes medical advice, diagnosis, or treatment. Always consult a qualified doctor or specialist before making any decisions about medication.

The weight loss medication landscape in Australia is changing rapidly. Information on this page may become outdated without notice. Data sourced from the TGA, FDA, MHRA, NICE, PBAC, Australian Prescriber, Obesity Evidence Hub, and clinical trial publications. Last reviewed March 2026.