I have type 2 diabetes. Are GLP-1 medicines for me?

Where do GLP-1s fit in Australian diabetes care?

Usually as an add-on, not the first medicine. The PBS sets out the order in which diabetes medicines are subsidised.¹

Most people start on metformin. The next step is usually an SGLT2 inhibitor (a tablet that makes the kidneys pass more sugar out in urine) or a DPP-4 inhibitor.¹ A GLP-1 is subsidised on the PBS when:¹

• an SGLT2 inhibitor didn't lower your sugar enough, didn't suit you, or couldn't be used, and
• your HbA1c is still above 7% on metformin, a sulfonylurea or insulin.

The PBS doesn't subsidise a GLP-1 together with a DPP-4 or SGLT2 inhibitor for diabetes, unless the SGLT2 inhibitor is for heart failure or kidney disease.¹ The first script needs an authority approval, which your doctor requests by phone or online.²

What you pay. On the PBS you pay the standard co-payment for each script, less with a concession card, and the safety net limits your yearly total.³ GLP-1 medicines aren't on 60-day dispensing, so it's one month at a time.¹

What is HbA1c, and how is it measured?

HbA1c is a common blood test that shows your average blood sugar over the last 2 to 3 months. It's the main number used to track type 2 diabetes.

Sugar in your blood sticks to haemoglobin, the protein in red blood cells. The test measures how much of it has sugar attached. The more sugar in your blood over those months, the higher the number.⁶

• Two units. Results may be given as a percentage, with mmol/mol beside it: 6.5% is the same as 48 mmol/mol.⁷
• No fasting needed. It's a normal blood draw, at any time of day.⁸
• The diabetes range. An HbA1c of 6.5% (48 mmol/mol) or above may mean diabetes.⁷
• The PBS line. For a GLP-1 to be subsidised, HbA1c has to be above 7% on your current treatment.¹

Ask your GP how often yours should be checked.

What HbA1c should I aim for?

You and your doctor agree a target. A lower target means less risk of long-term damage, but more risk of low sugar, so it differs from person to person.⁹

What one international guideline says:

Your own target is set with your GP or diabetes team.

How do they compare with metformin, and can I take both?

Metformin is a common first tablet for type 2 diabetes. In a direct comparison, a weekly GLP-1 lowered HbA1c a little more than metformin. The two can also be taken together.

A fall in HbA1c of 1 point means, for example, going from 8% to 7%. The two trials below compared medicines with each other, not with a dummy treatment.

Average fall in HbA1c, in percentage points:

These are averages from two separate trials with different people, so don't compare numbers across the two cards. The Ozempic label reports no new safety problems in 959 people who took it with metformin in trials.¹²

What if I also take insulin or a sulfonylurea?

Then your risk of low sugar (a hypo) goes up. Your doctor may lower your insulin or sulfonylurea dose when you start.

Sulfonylureas are older tablets such as gliclazide and glimepiride. The Ozempic label warns that combining them with a GLP-1 can cause hypos, including severe ones.¹² The Australian Wegovy product information says to consider lowering the insulin or sulfonylurea dose.¹³ That's your doctor's call, so don't change doses yourself.

Signs of low sugar include:¹²

• dizziness, shaking or sweating
• hunger
• blurred vision
• a fast heartbeat
• confusion or drowsiness

What about my kidneys and eyes?

For kidneys, one large trial found fewer serious kidney problems on semaglutide in people who already had kidney disease. For eyes, tell whoever checks your eyes that you've started, especially if you have retinopathy (damage to the back of the eye from diabetes).

A large kidney trial followed 3,533 people who had type 2 diabetes and kidney disease, for about 3.4 years. Half took semaglutide (Ozempic) 1 mg a week, half a dummy injection with no medicine in it.¹⁵

The researchers counted everyone who had any one of these:¹⁵

• kidney failure: needing dialysis or a transplant, or kidney function falling very low
• losing at least half of their kidney function
• dying from kidney or heart causes

Out of every 100 people, how many had one or more of these:

What this means. Semaglutide lowered the risk of these events by about a quarter (24%).¹⁵ Put simply: for every 22 people treated for about 3 years, one fewer person had kidney failure, a big loss of kidney function, or died from kidney or heart causes. The difference was clear enough that the trial was stopped early.¹⁵ This was in people who already had kidney disease, so it doesn't show the medicine protects healthy kidneys.

But vomiting or diarrhoea can dry you out, and that can damage the kidneys.¹²

Eyes. In a 2-year trial in people with type 2 diabetes, eye complications from retinopathy were more common on Ozempic than on a dummy injection. The gap was bigger in people who already had retinopathy.¹²

Out of every 100 people, how many had eye complications:

Bars for eyes are drawn on a scale up to 10 in 100.

Ozempic is now also approved in Australia to lower the risk of kidney decline and heart-related death in people with type 2 diabetes and kidney disease.¹⁶ Report any change in your vision.¹²

Will I lose as much weight as people without diabetes?

On average, people with diabetes lost less in trials. Two trials of semaglutide 2.4 mg, the weekly dose sold as Wegovy, each ran for 68 weeks (about 16 months).

Average share of body weight lost, and what that means for someone who starts at 90 kg (198 lb):

What this means. These are separate trials with different people, so the gap between them is a rough guide, not a direct comparison. They are averages too, so your own result may be higher or lower.

What to read next, in order

These four guides go deeper. Each one ends with a link to the next, so you can read them one after another.

1. 1Weight and health: what BMI and waist numbers meanGuide 1 of 9UnderstandHow weight links to diabetes, and why Australian guidance uses lower BMI cut-offs for some groups.
2. 2What do GLP-1 medicines do?Guide 2 of 9UnderstandHow these medicines release insulin only when sugar is high.
3. 3Side effects and risksGuide 5 of 9DecideStomach effects, and the risks that matter more with diabetes.
4. 4Getting a prescription in Australia, and the medicinesGuide 6 of 9Do it safelyThe brands approved for diabetes, the PBS criteria and authority scripts, and what you pay.