From the desk of an Australian general practitioner
If you are over 30 and living with type 2 diabetes or prediabetes, you already know the daily battle. The constant worry about blood sugar levels. The creeping weight gain that makes you feel exhausted and frustrated. The fear of needles if insulin is ever mentioned. The terrifying thought of heart attack, stroke, kidney failure or losing your eyesight. On top of that, the cost of medications and specialist appointments can feel overwhelming, especially if you live outside a major city.
What if I told you that one of the most powerful weapons against type 2 diabetes is not new, not expensive, and not injected? As an Australian doctor, I see it every week: metformin. This humble tablet has been used for decades, is backed by enormous evidence, and remains the first-choice medication in almost every type 2 diabetes treatment plan. If you are not already on it, you may be missing out on one of the safest and most affordable ways to protect your future.
Metformin belongs to a class of medicines called biguanides. In plain English, it works mainly by reducing the amount of glucose your liver releases into your bloodstream and by making your body’s cells more sensitive to insulin. It does not push your pancreas to pump out more insulin, which is why it is very unlikely to cause dangerously low blood sugar when used on its own.
For busy Australians over 30, metformin offers several practical advantages:
| Feature | Details |
|---|---|
| Drug class | Biguanide |
| Main action | Reduces liver glucose output, improves insulin sensitivity |
| Typical HbA1c reduction | Approximately 1–1.5% |
| Effect on weight | Neutral or modest weight loss |
| Risk of hypoglycaemia alone | Very low |
| PBS listed | Yes — first-line therapy |
| Route | Oral tablet (500 mg, 850 mg, 1000 mg) |
Naturally, you want to know: is metformin safe? What do I need to watch out for? Below I answer the most common questions I hear from patients over 30 in my Australian practice.
Because metformin is cleared by the kidneys, your doctor will check your kidney function using a blood test called creatinine and eGFR. The good news is that regular monitoring is straightforward. In Australia, standard practice is:
| eGFR (mL/min/1.73 m²) | Recommended Action |
|---|---|
| 90 or above | Continue metformin; check kidney function at least yearly |
| 60–89 | Continue metformin; check at least yearly |
| 45–59 | Continue with regular review; check every 6 months |
| 30–44 | Use with caution; reduce maximum dose; check every 3–6 months |
| Below 30 | Stop metformin and discuss alternative options |
This monitoring protects your kidneys and keeps metformin safe for the long term. It is a simple blood test — no needles in the sense of daily injections, just routine pathology.
If you are booked for an elective operation, your surgical team or GP will usually advise you to withhold metformin on the day of surgery while you are fasting. This reduces the risk of dehydration and kidney stress during the operation. For most minor procedures, you simply stop it on the morning of surgery and restart it once you are eating and drinking normally and your kidney function has been checked.
For larger operations, or if you are having imaging with contrast dye, your doctor may advise holding metformin for 24–48 hours around the procedure and restarting only after confirming your kidneys are stable. The rule is simple: fasting = no metformin; eating and stable kidneys = restart metformin. Always confirm with your treating team, but do not stop metformin for minor everyday blood tests unless specifically told.
The fear of lactic acidosis is the most misunderstood aspect of metformin. Lactic acidosis is a rare but serious build-up of acid in the blood. In the general population, the risk is extremely low — roughly 3 to 10 cases per 100,000 patient-years. To put that in perspective, you are far more likely to be injured in a car accident than to develop lactic acidosis from metformin.
The risk increases significantly only when metformin is used in people with severe kidney failure, severe liver disease, serious dehydration, shock, or prolonged fasting during major surgery. That is exactly why we monitor kidney function and temporarily pause the drug around surgery. When used correctly, metformin has an excellent safety record after more than 60 years of use worldwide.
Alcohol and metformin can both affect the liver and increase the risk of lactic acidosis, particularly with heavy or binge drinking. The practical advice I give my patients is:
Remember, alcohol itself can raise or lower blood sugar unpredictably. Sensible limits protect both your liver and your blood sugar control.
Many antipsychotic medicines — especially olanzapine, clozapine and quetiapine — can cause significant weight gain, insulin resistance and high blood sugar. This is a real concern for patients over 30 who need these medications for schizophrenia, bipolar disorder or severe depression. The good news is that metformin is increasingly used to counteract these metabolic side effects. Australian psychiatrists and GPs often add metformin to help reduce antipsychotic-induced weight gain and improve glucose metabolism. If you or a loved one is on antipsychotic medication and struggling with weight or rising blood sugars, ask your treating doctor whether metformin could be part of the solution.
Here is a reassurance many patients love to hear: metformin on its own very rarely causes hypoglycaemia. Because it does not force the pancreas to release extra insulin, it does not drive blood sugar dangerously low the way some other diabetes tablets can. This means fewer shaky, sweaty episodes, less need for emergency snacks, and less fear of collapsing. However, if metformin is combined with a sulfonylurea (like gliclazide or glipizide) or insulin, hypoglycaemia can occur. In that case, your doctor will adjust doses and teach you how to recognise and manage lows. Used alone, metformin gives you smoother blood sugar control without the constant threat of severe lows.
Living in a rural or remote part of Australia creates unique diabetes challenges: fewer specialists, long distances to pharmacies, extreme heat, and sometimes limited refrigeration. Metformin is a rural-friendly medicine. It is:
For remote Australians, starting metformin early can help prevent the need for more complex, injectable treatments and reduce hospitalisations from diabetes complications.
In Australia, metformin is the undisputed first-line medication for type 2 diabetes. It is recommended by the Royal Australian College of General Practitioners (RACGP), Diabetes Australia, and the Australian Diabetes Society. It is listed on the PBS, meaning the government subsidises its cost. It is also included in the 60-day dispensing scheme, which allows many patients to receive a two-month supply with one script — fewer GP visits, fewer pharmacy fees, and less hassle.
Metformin also fits perfectly into a GP Management Plan (GPMP) and Team Care Arrangements (TCA). These Medicare-funded plans allow your GP to coordinate care with diabetes educators, dietitians, physiotherapists and podiatrists. Metformin is not a stand-alone magic pill, but when combined with lifestyle changes and a structured care plan, it gives you the best chance of avoiding heart disease, kidney damage, nerve pain and vision loss.
Why Australian GPs keep returning to metformin: It is affordable, effective, safe when monitored, weight neutral, protective for the heart, and it keeps future treatment options open. If you are over 30 and living with type 2 diabetes or prediabetes, this medicine is often the foundation everything else is built on.
Do not wait until your next complication. If you have been diagnosed with type 2 diabetes and you are not taking metformin, or if you have been told you have prediabetes and want to prevent progression, I encourage you to book a consultation with your GP this week.
Here is a simple checklist to bring to your appointment:
Your future health is worth a conversation. Metformin is not just a cheap diabetes tablet — for millions of Australians it is the key to steadier blood sugar, a healthier heart, and a life less dominated by diabetes. Talk to your GP about whether metformin belongs in your treatment plan. Your body will thank you for it.
Disclaimer: This article is for educational and informational purposes only and does not replace individual medical advice. Metformin is a prescription-only medicine in Australia. Always consult your GP or specialist before starting, stopping or changing any medication. The information provided reflects general Australian clinical practice and may not apply to every individual.