Attention: Are You Tired, Foggy, and Battling Your Weight After 30?

If you are over 30 and feel like your body is working against you—constant sugar cravings, weight collecting around the middle, afternoon energy crashes, brain fog, low mood, or blood tests showing “borderline sugar”—you are not alone. Millions of Australians live with insulin resistance, a condition where the body’s cells no longer respond properly to insulin. Insulin resistance sits at the centre of type 2 diabetes, polycystic ovary syndrome, fatty liver, and many cardiovascular risks.

Here is the clinical reality: metformin is one of the most effective, safest, and cheapest medicines we have for this metabolic problem. It has been used for more than 60 years, is backed by Australian guidelines, and costs most patients only a standard PBS co-payment. This is not a fad. It is a foundation treatment.

Interest: What Metformin Actually Does in Your Body

Metformin works mainly by reducing the liver’s excess production of glucose. It also improves how muscle and fat cells take up and use glucose, and it has beneficial effects on hunger, weight, inflammation, and cardiovascular risk. Unlike some diabetes medicines, metformin does not stimulate insulin release, so it rarely causes dangerous hypoglycaemia when used alone.

Many patients ask: “Will this make me feel better?” The answer is often yes—not overnight, but over weeks to months. Cravings may settle, energy becomes more stable, and weight may slowly improve. The most common side effects are mild nausea, loose bowels, or bloating, especially when the dose is increased too quickly. Taking metformin with food and using the extended-release form can dramatically reduce these issues.

Desire: Why Patients Ask Me About Metformin and Why I Keep Recommending It

How Metformin Helps with Insulin Resistance

Think of insulin resistance as a door that is stuck. Your pancreas produces more and more insulin to push glucose into cells, but the cells are not listening well. This high insulin state drives hunger, fat storage, fatigue, and hormonal chaos. Metformin helps unstick that door. It improves the sensitivity of insulin receptors, lowers fasting insulin, reduces liver glucose production, and reduces inflammation. For many patients, this means fewer cravings, steadier energy, and an easier time managing weight.

Metformin and Depression: Any Effect?

Depression and metabolic dysfunction often travel together. People with insulin resistance or type 2 diabetes are more likely to experience low mood, fatigue, and cognitive dullness. While metformin is not an antidepressant, a growing body of observational research and small trials suggests that metformin may improve depressive symptoms in some people—likely by lowering inflammation, improving insulin sensitivity, and stabilising energy. If you have low mood plus metabolic issues such as prediabetes or PCOS, treating the metabolism with metformin may give your mental health treatment a better foundation. It does not replace psychology or antidepressant therapy, but it can be a useful supporting tool.

Is Metformin Available as a Liquid in Australia?

Yes, with caveats. Metformin is widely available in Australia as tablets, including extended-release tablets. For people who struggle to swallow large tablets, metformin oral liquid 100 mg/mL can be prepared by a compounding pharmacy, and some commercial oral liquid formulations exist. However, PBS subsidy in Australia is mainly for tablet forms, so liquid metformin may cost more or require a private prescription. If swallowing tablets is a genuine problem, ask your pharmacist about liquid options or ask your GP about alternative dosing strategies.

What Is the PBS Co-Payment for Metformin?

Metformin is one of the most affordable medicines in Australia. Because it is PBS-listed for type 2 diabetes, most patients pay only the standard PBS co-payment rather than the private price. The table below gives approximate figures.

If metformin is prescribed for conditions other than type 2 diabetes, such as PCOS or prediabetes, PBS subsidy may not apply. Even as a private prescription, metformin remains relatively inexpensive. Check pbs.gov.au for current costs.

RACGP Guideline for Metformin Initiation

The Royal Australian College of General Practitioners and Diabetes Australia recommend metformin as the first-line glucose-lowering medicine for adults with type 2 diabetes, especially in people who are overweight or obese, unless there is a contraindication. The usual approach in Australian general practice is:

Metformin should not be started if eGFR is below 30 mL/min/1.73 m². For eGFR 30–45, lower doses and close monitoring are required. Your GP will guide you.

Metformin and Fasting: Guidance for Ramadan

For Muslim Australians, fasting during Ramadan can raise real concerns about diabetes medicines. Metformin is one of the safest glucose-lowering medicines during fasting because it rarely causes hypoglycaemia when used alone. A common plan is to take the larger dose at iftar and the smaller dose at suhoor, or use extended-release metformin once at iftar. Avoiding dehydration is essential. If you have reduced kidney function, heart failure, or take other medicines such as insulin or sulfonylureas, your doctor may recommend a temporary dose reduction or a supervised fasting plan. Never stop or change your metformin dose without medical advice.

Metformin and Coronary Artery Disease

People with type 2 diabetes have a much higher risk of heart attacks. Metformin is one of the few diabetes medicines with proven cardiovascular benefits. The landmark UKPDS study showed that metformin reduced diabetes-related death and myocardial infarction in overweight people with type 2 diabetes. Metformin improves lipid profiles, reduces weight, improves vascular function, and lowers inflammatory markers. If you have stable coronary artery disease and type 2 diabetes, metformin is usually continued because it treats the metabolic disease driving the artery damage. It may need to be temporarily withheld before certain contrast scans or during acute illness, then restarted.

Can Metformin Cause Nephrogenic Diabetes Insipidus?

No. Metformin is not known to cause nephrogenic diabetes insipidus. Nephrogenic diabetes insipidus is a condition where the kidneys do not respond properly to antidiuretic hormone, leading to large volumes of dilute urine and excessive thirst. It is most commonly linked to lithium, high calcium levels, certain kidney diseases, or genetic conditions. If you develop excessive thirst and urination while taking metformin, do not assume it is the metformin—your doctor will check blood glucose, kidney function, and other medicines, because high blood glucose itself can cause similar symptoms.

Action: Ask Your GP Whether Metformin Is Right for You

Given its safety record, low cost, and broad metabolic benefits, metformin is one of the medicines I most commonly recommend to patients with type 2 diabetes and insulin-resistant conditions. It is not a stimulant, not a quick fix, and not a replacement for a healthy lifestyle—but it can make your efforts work better.

If you recognise yourself in the tired, cravings, weight-creep pattern, now is the time to act. Book a GP appointment and ask: “Could metformin help my insulin resistance or diabetes?”

• Bring recent blood tests: fasting glucose, HbA1c, eGFR, liver function, and lipids.
• Ask about starting low and slow to minimise gut side effects.
• If you have trouble swallowing tablets, ask about liquid metformin or extended-release options.
• Check your PBS co-payment and Safety Net status at pbs.gov.au.
• If you have diabetes and plan to fast, discuss a Ramadan plan with your GP.

As a doctor in Australia, I see metformin as one of the best value medicines we have. For many people, it is the difference between slowly losing the metabolic battle and finally getting back in control.