Phentermine in Australia: 2026 Guide

Phentermine is the most prescribed oral weight loss medication in Australia, best known under the brand name Duromine. It's a prescription-only appetite suppressant costing roughly $80–$150 a month — the lowest-cost prescription option in the weight loss space, with correspondingly more modest results than the newer injectables. Here's how it works, the brands available in Australia, and how to access it safely.

The short answer at a glance

• What is it? A stimulant-class appetite suppressant taken as a once-daily capsule.
• Brands in Australia: Duromine and Metermine — the same active ingredient (phentermine), typically at the same strengths.
• Strengths: 15mg, 30mg and 40mg.
• Cost: roughly $80–$150/month, private script — not PBS-subsidised.
• Prescription: required, always — available via bulk billed telehealth assessment.

Duromine vs Metermine: what's the difference?

Functionally, nothing that matters clinically. Both are phentermine in the same capsule strengths; they're different brands, and pharmacies sometimes price them differently or stock one but not the other. If your pharmacy quotes a better price on one brand, ask your GP to prescribe by active ingredient so the pharmacist can dispense whichever is cheaper — a simple way to save on an identical medicine.

How phentermine works — and what results to expect

Phentermine stimulates the central nervous system to reduce appetite. You eat less because you're less hungry, not because your body processes food differently. In studies and clinical practice, average results are modest — a mid single-digit percentage of body weight over a supervised course, always alongside dietary change. For comparison, the modern injectable class averages roughly 15–21% in trials; the trade-off is cost and injection versus a cheap daily capsule. Our all-options comparison puts every medication side by side.

Safety: who shouldn't take phentermine

As a stimulant, phentermine is unsuitable for people with uncontrolled high blood pressure, heart disease or rhythm problems, hyperthyroidism, glaucoma, significant anxiety disorders, a history of stimulant dependence, and during pregnancy or breastfeeding. It interacts with several medications, notably MAOI antidepressants. Common side effects include insomnia, dry mouth, restlessness and elevated heart rate or blood pressure — which is why treatment should always run under GP review, with blood pressure checked along the way.

How to get phentermine in Australia

A doctor's assessment is the only legitimate route. Via telehealth that means: a bulk billed GP consultation covering your health history, cardiovascular risk and goals; a clinical decision on whether phentermine (or a different treatment) is appropriate; and if prescribed, an eScript to your preferred pharmacy with scheduled follow-up. Our full guide to the brand most Australians know — Duromine in Australia — covers the practical details, and alternatives like Contrave and Xenical suit patients who can't take stimulants.

Frequently Asked Questions — Phentermine in Australia

Is phentermine legal in Australia?

Yes — it's a TGA-registered prescription medicine, legally available with a valid prescription from an Australian-registered doctor. Buying it without a prescription, including from overseas websites, is neither legal nor safe.

Is phentermine the same as Duromine?

Duromine is the best-known Australian brand of phentermine; Metermine is another. Same active ingredient, same strengths.

How much does phentermine cost in Australia?

Roughly $80–$150 a month depending on brand, dose and pharmacy. It is not PBS-subsidised, but the GP consultations around it can be bulk billed.

Can I get phentermine through telehealth?

Yes — assessment, prescribing where appropriate, and follow-up can all be done via telehealth by an Australian-registered GP. Request an appointment to start with a bulk billed consultation.

What's stronger — phentermine or the injectable medications?

The injectables produce substantially larger average weight loss in head-to-head terms (roughly 15–21% versus mid single digits). Phentermine's advantages are price and oral dosing. Which fits you is a clinical decision based on your health profile and goals.

This article is general information, not personal medical advice. Prescription decisions always rest with your doctor after an individual assessment. Pricing current as at mid-2026.