Weight Loss Medication Australia: Comprehensive Guide to Options, Safety, and Access (2025)

Table of Contents

1. Why Medication? The Obesity Landscape Down Under

2. Regulatory Snapshot: How the TGA Classifies Weight-Loss Drugs

3. Prescription-Only Weight Loss Medications in Australia 3.1 GLP-1 Receptor Agonists (Saxenda, Wegovy, Ozempic) 3.2 Appetite Suppressants (Duromine / Phentermine) 3.3 Combination Therapy (Contrave) 3.4 Lipase Inhibitor (Xenical / Orlistat) 3.5 Off-Label Agents (Topiramate, Metformin)

4. Compounded & Emerging Treatments

5. Over-the-Counter & Complementary Options

6. Access Pathways: GP, Telehealth, Specialist Clinics

7. Cost Comparison Table

8. Risks, Contraindications & Monitoring

9. Frequently Asked Questions

10. Key Takeaways

Weight Loss Medication Australia: Ozempic is a key player.

1. Why Medication? The Obesity Landscape Down Under

Australia’s obesity rate hovers around 31 % in adults, according to the Australian Institute of Health and Welfare (AIHW). Lifestyle modification remains the gold standard, yet for individuals with a BMI ≥ 30 kg/m² (or ≥ 27 with comorbidities), medication can bridge the gap between diet-and-exercise best efforts and clinically meaningful weight reduction.

“Pharmacotherapy is not a silver bullet but a powerful adjunct when behaviour change alone plateaus,” notes obesity specialist Dr Samantha Hocking of the University of Sydney link

2. Regulatory Snapshot: TGA Classification

Australia’s Therapeutic Goods Administration (TGA) categorises weight-loss drugs as Schedule 4 (Prescription-Only) medicines. The TGA evaluates:

• Efficacy (≥ 5 % placebo-adjusted weight loss over 12 months)

• Safety data (cardiovascular outcomes, cancer signal)

• Post-marketing surveillance requirements

Any medication discussed below has either full TGA approval or is dispensed under “Special Access Scheme C” when in shortage (e.g., Wegovy in 2025).

3. Prescription-Only Weight Loss Medications in Australia

Overview Table

Brand/Generic	Mechanism	Typical % Weight Loss*	PBS?	First-Line?
Saxenda (liraglutide)	GLP-1 RA	7–10 %	No	Yes
Wegovy (semaglutide 2.4 mg)	GLP-1 RA	12–15 %	No (2025)	Yes
Ozempic (semaglutide 1 mg)†	GLP-1 RA (off-label)	10–12 %	PBS for T2D	Off-label
Duromine (phentermine)	Sympathomimetic	5–7 %	No	Short-term
Contrave (naltrexone/bupropion)	Appetite & reward pathway	6–8 %	No	Second-line
Xenical (orlistat)	Lipase inhibitor	4–6 %	No	Second-line

*Average after 12 months with lifestyle counselling.†TGA-approved for type 2 diabetes, commonly prescribed off-label for obesity during Wegovy shortages.

3.1 GLP-1 Receptor Agonists

Mechanism: Mimic glucagon-like peptide 1, slowing gastric emptying and reducing appetite.

Saxenda (liraglutide 3 mg daily)

• Dose: Titrated weekly 0.6 → 3 mg subcutaneous.

• Evidence: 56-week SCALE trial showed 8.4 % mean weight loss – Astrup et al., 2015 link.

• Side-effects: Nausea (39 %), transient vomiting (15 %), gallstones.

Wegovy (semaglutide 2.4 mg weekly)

• Dose: 0.25 mg → 2.4 mg weekly over five months.

• Evidence: STEP 1 trial: 14.9 % mean weight loss vs. 2.4 % placebo – Wilding et al., NEJM 2021 link.

• Status: Launched AU Q4 2024; supply constrained through 2025.

Ozempic (semaglutide 1 mg weekly)

Prescribed off-label for obesity due to Wegovy shortages. TGA advisory urges GPs to reserve Ozempic for diabetics; many clinics now require BMI > 35 for off-label scripts.

3.2 Duromine (Phentermine)

Oldest TGA-approved therapy (since 1990s).

• Mechanism: Sympathomimetic amine suppresses appetite.

• Schedule: S4 (controlled). Max 12-week courses.

• Cautions: Insomnia, palpitations, elevated blood pressure; contraindicated in cardiovascular disease.

• Author note: “Phentermine can be helpful if carefully screened, but we monitor BP fortnightly,” says Dr Priya Seidel (Endocrinology SA) link.

3.3 Contrave (Naltrexone/Bupropion)

• Mechanism: Targets hypothalamic appetite centre (bupropion) and reward pathway (naltrexone).

• Dose: Escalate to 2 tabs BID.

• Pros: Beneficial for emotional/hedonic eating.

• Cons: Nausea (32 %), seizure risk in predisposed, interacts with SSRIs.

3.4 Xenical (Orlistat)

• Mechanism: Blocks intestinal lipase → ~30 % dietary fat malabsorption.

• Drawbacks: Steatorrhoea if fat > 15 g per meal; mandates fat-soluble vitamin supplementation.

• Best for: Patients preferring non-appetite-acting drug or contraindicated for stimulants/GLP-1s.

3.5 Off-Label Agents

Drug	Rationale	Typical Use	Caveats
Topiramate	GABA modulation ↓ appetite	Combined with phentermine overseas (Qsymia)	Cognitive fog, paresthesia
Metformin	Improves insulin resistance → ↓ hunger	PCOS patients, pre-diabetes	GI upset, B12 deficiency
Tirzepatide (Mounjaro)	Dual GIP/GLP-1 agonist	Compassionate supply for BMI > 40	Not yet TGA-approved for obesity (2025)

4. Compounded & Emerging Treatments

With global GLP-1 shortages, some Australian compounding pharmacies market semaglutide/tirzepatide injectables. The TGA warns these lack the rigorous sterility and bioequivalence checks of branded products. Always verify:

1. Pharmacy is APC-accredited.

2. Active ingredient sourced from Good Manufacturing Practice (GMP) supplier.

3. Batch sterility and potency certificates supplied.

Emerging pipeline: Retatrutide (triple agonist) in Ph-II; expected TGA submission ~2026.

5. Over-the-Counter & Complementary Options

Category	Examples	Evidence Quality	Notes
Fibre bulking agents	Psyllium, glucomannan	Moderate; small appetite reduction	Safe adjunct, minimal weight loss alone
Green tea / EGCG	Capsules, drinks	Weak; ~1 kg over 12 weeks	Mild stimulant effect
Garcinia cambogia	HCA extract	Poor; inconsistent	TGA issued warning for liver toxicity (2019)
Apple cider vinegar gummies	Multiple brands	Anecdotal	May erode tooth enamel, GI upset

Key point: Over-the-counter products cannot legally claim “weight loss medication” in Australia without TGA listing (AUST L) or registration (AUST R).

6. Access Pathways: GP, Telehealth, Specialist Clinics

1. General Practitioner (GP)First-line for Duromine, Xenical, Metformin.

2. Obesity Specialist / EndocrinologistFor complex cases or GLP-1 scripts when BMI > 35.

3. Telehealth Platforms (e.g., Juniper, Mosh)Offer asynchronous scripts + couriered pens; ensure platform employs AHPRA-registered doctors.

4. Hospital Bariatric ClinicsMay combine pharmacotherapy with surgery candidacy.

Monitoring: Weight, waist, BP, HbA1c, lipids every 3–6 months; gallbladder ultrasound if rapid loss.

7. Cost Comparison (AUD, 2025)

Medication	Dose	Pack Price	Monthly Cost	PBS Subsidy
Saxenda	6 mg/3 ml x 5 pens	$390	$390–$630 (dose-dependent)	❌
Wegovy	2.4 mg pen	$400	$400	❌ (waiting PBS review)
Ozempic (off-label)	1 mg x 4 doses	$140	$140 (if private)	✔ for T2D only
Duromine	30 mg x 30 caps	$120	$120	❌
Contrave	112 tabs	$270	$270	❌
Xenical	84 caps	$105	$105	❌
Compounded semaglutide	1 mg/mL 4 mL	$250	$250	❌ (not TGA-approved)

8. Risks, Contraindications & Monitoring

Drug Class	Major Contraindications	Key Monitoring
GLP-1 RAs	Medullary thyroid carcinoma, MEN 2, pancreatitis history	Fasting lipase, gallstones, GI symptoms
Phentermine	Uncontrolled hypertension, CAD, hyperthyroidism, pregnancy	BP, pulse, insomnia, mood
Naltrexone/Bupropion	Seizure disorder, opioid use, uncontrolled HTN	BP, mood changes, liver enzymes
Orlistat	Chronic malabsorption, cholestasis, pregnancy	ADEK vitamins, GI side-effects

9. Frequently Asked Questions

Q1: Can I buy Wegovy online without a script?A: No. Wegovy is Schedule 4 in Australia—legal supply requires a valid prescription dispensed by a TGA-approved pharmacy.

Q2: Is compounded semaglutide safe?A: Safety depends on the compounding pharmacy’s GMP sourcing and sterile technique. The TGA cautions there is no guarantee of potency equivalence – see advisory (TGA, Feb 2025) link.

Q3: Will Medicare cover weight loss medications?A: Currently only Ozempic under its diabetes indication attracts PBS subsidy. Lobby groups (Obesity Collective) are pushing for Saxenda/Wegovy listing; decision pending.

Q4: How quickly will I lose weight?A: Typical trajectory:

• GLP-1: 0.5–1 kg/week first 3 months, then plateau.

• Phentermine: fast initial drop (water weight), slower thereafter.Expect to combine with calorie deficit and 150 min exercise/week for best results.

10. Key Takeaways

• Weight loss medication Australia spans GLP-1 injectables, stimulants, combination pills, and fat-absorption blockers—each with unique benefits and risks.

• GLP-1 agents (Saxenda, Wegovy) lead efficacy tables but cost $400+/month and may cause GI issues.

• Duromine remains popular for quick results but demands cardiovascular screening.

• Contrave suits emotional eaters; Xenical helps fat malabsorption but mandates low-fat diet.

• Access via GP, telehealth, or specialist ensures structured monitoring; self-sourcing overseas drugs is risky and illegal.

• Medication is a tool, not a cure—behaviour change and ongoing medical oversight are essential.

Disclaimer: This article is for educational purposes only and is not medical advice. Consult an AHPRA-registered healthcare professional before starting any weight-loss medication.

References

1. Wilding, J.P.H., et al. “Once-Weekly Semaglutide in Adults with Overweight or Obesity.” NEJM, 2021.

2. Astrup, A., et al. “Liraglutide Effect and Action in Diabetes Study.” NEJM, 2015.

3. Australian Institute of Health and Welfare. “Overweight and Obesity in Australia,” 2023 update.

4. TGA. “Safety Advisory: Compounded GLP-1 Products,” 2025.

5. Seidel, P. Interview on phentermine protocols. Adelaide Endocrinology Conference, March 2024.