Overview
Quick answer
Australia has no standard blood-test panel for people using GLP-1 or GIP medicines. What your doctor orders follows your own health history and the condition being treated, not the medicine itself.
Blood tests describe metabolic health around treatment. They cannot confirm a medicine is working, and the eye and gallbladder problems people worry about are found by examination and imaging, not bloodwork.
Overview
Key takeaways
GLP-1 and GIP are hormones your own gut releases in response to food, and these medicines act at the receptors those hormones act on.
Their effects are on insulin timing, glucagon, the speed the stomach empties, and appetite signalling in the brain.
None of those four effects is a substance a blood sample measures, which is why no marker reports whether the medicine is doing its job.
Gastrointestinal effects are the common ones: in the Australian weight-management trials nausea affected 27.5 per cent against 8.5 per cent on placebo.
For type 2 diabetes, Australian guidance describes HbA1c every three to six months, lipids individualised to risk, urine albumin at least annually, and kidney function where indicated.
Australia has no universal recurring blood-test panel for people on GLP-1 or GIP medicines.
Australian product information for this class records that no information is available on effects on laboratory tests.
Testing does four separate jobs, and collapsing them into one question is where most of the confusion starts.
In a large cardiovascular outcomes trial the benefit did not track the change in HbA1c, so a moving marker is not proof a treatment is working.
Sudden vision loss needs urgent medical attention, and no blood test can rule it out.
Australian general practice guidance describes no role for routine pancreatic enzyme testing unless pancreatitis is suspected.
Markers used as endpoints in clinical trials are not a personal monitoring schedule.
Hemexa does not prescribe, dispense, or supply GLP-1 medicines, GIP medicines, or peptides.
Scope
Who this page is for
If you are on one of these medicines, or talking to your doctor about starting, you have probably been told that bloodwork matters and not told much about which bloodwork or why. That gap is what this page is for.
It is not a guide to obtaining these medicines, it does not compare them with each other, and it names no products.
This page is written for
- People whose doctor has started them on treatment and who want to understand the tests they are asked to have
- People with an existing metabolic diagnosis who already have regular pathology and want to know what changes
- People considering treatment who want to understand baseline testing before a conversation with their GP
- Anyone who has read that a specific panel is required and wants to know where that idea comes from
If you are looking for treatment advice, the right conversation is with your own doctor, who can see your full history.
How they work
What GLP-1 and GIP actually do
GLP-1 stands for glucagon-like peptide-1. It is a hormone your own gut releases in response to food. Australian general practice guidance describes it as one of the two main incretin hormones triggered by eating, and the other one is GIP, or glucose-dependent insulinotropic polypeptide.
These medicines do not add a new signal to the body. They act at the receptors those two hormones already act on, which is why the class is described as receptor agonists: an agonist is a molecule that switches a receptor on in place of the hormone that normally does it.
Insulin, but only when glucose is high
Australian general practice guidance lists stimulating insulin secretion among the effects, and Australian product information describes that insulin release happening in a glucose-dependent manner. Because the effect follows the glucose level rather than overriding it, the risk of blood sugar falling too low is described as minimal unless the medicine is combined with insulin or a sulphonylurea.
Less glucagon, and less glucose made by the liver
The same guidance lists a reduction in glucagon secretion and in hepatic gluconeogenesis, which is the liver making glucose itself rather than absorbing it from food. It also records that the body keeps its normal glucagon response if blood sugar does fall too low, so the counter-regulation still works.
A slower stomach
Australian product information describes delayed gastric emptying, largest at first and diminishing over time. Slowing how fast a meal leaves the stomach blunts the glucose rise that follows it. It is also where most of the early nausea comes from, which is why gastrointestinal effects are the most frequently reported ones in trials.
Appetite signalling in the brain
Australian product information states that both GIP and GLP-1 receptors are found in areas of the brain important for appetite regulation, and that GIP receptors are also present on adipocytes, the body’s fat cells. General practice guidance describes promotion of satiety leading to reduced caloric intake, and attributes weight loss on this class to that effect together with the slower stomach.
Read those four together and something becomes obvious. Every one of them is a change in signalling, appetite, or the speed of digestion. None of them is a substance that shows up in a blood sample and reports how well the medicine is doing its job.
That is the single fact the rest of this page rests on. Blood tests describe the metabolic state those changes eventually produce, which is genuinely useful and is why your doctor still orders them. They do not measure the mechanism itself.
What to expect
What side effects are actually common
Before any of the testing questions, most people want to know something simpler: what does this actually feel like, and is what I am experiencing normal?
Australian product information reports adverse effects with a frequency scale. Very common means at least one person in ten. Common means between one in a hundred and one in ten. Here is what that looks like in the trials the registered GIP and GLP-1 medicine was approved on, with the placebo group beside it.
Gastrointestinal effects, and they are the main event
Across the weight-management trials, pooled over all treatment arms: nausea in 27.5 per cent against 8.5 per cent on placebo, diarrhoea 20.9 against 7.8, constipation 13.6 against 5.2, and vomiting 10.8 against 2.2. In the diabetes trials the same effects appear at roughly half those rates. Product information records that these were mostly mild or moderate, occurred more often while treatment was being stepped up, and decreased over time.
The less-discussed ones
Also more common than placebo in the weight-management trials: reduced appetite at 9.8 per cent against 2.9, indigestion at 9.3 against 3.9, abdominal pain at 5.2 against 2.9, dizziness at 4.5 against 2.1, and hair loss at 4.7 per cent against 0.8. Hair loss rarely comes up in coverage and it is in the Australian product information.
Raised lipase is common enough to expect
In the diabetes trials, increased lipase was reported in 3.2 per cent of people on treatment against 2.6 per cent on placebo. This is the single best reason the page later argues against routine pancreatic enzyme testing: the rise is common, it happens on placebo too, and on its own it does not tell anyone anything.
Low blood sugar is mostly a combination problem
Australian general practice guidance describes hypoglycaemia risk on this class as minimal on its own, and something to plan for when the medicine is combined with insulin or a sulphonylurea. Australian product information lists hypoglycaemia as an adverse reaction specifically in those combinations. If you are on neither, it is a much smaller consideration.
A small rise in heart rate
Australian general practice guidance describes a mild reversible increase in heart rate on this class, averaging two to three beats per minute, and states that it does not appear to have clinical implications. It is worth knowing about mainly so that noticing it does not become alarming.
What is not just settling in
Two things do not belong on a wait-and-see list. Any sudden change in vision needs urgent assessment, and the TGA advises stopping and seeking prompt medical attention. Severe abdominal pain that does not settle needs assessment rather than a scheduled test. Prolonged vomiting or diarrhoea matters too, because dehydration can affect kidney function.
Notice what that list is and is not. It describes how often things happened to people in trials, under supervision, on a product whose contents were known.
It does not tell you what will happen to you, and no blood test on this page will tell you either. That is the honest boundary, and the rest of the page is about where testing sits inside it.
Australian context
Where these medicines sit in Australia
These are separate facts and are easiest to understand when they stay separate. Registration, scheduling, and how a medicine may be discussed publicly are three different things.
Prescription-only
These are Schedule 4 medicines under the Poisons Standard, the legislative instrument that sets how tightly each substance is controlled in Australia. Schedule 4 means prescription only: supplied through a pharmacy against a prescription, which means a clinician has assessed whether treatment is appropriate for that person.
Registration is per product and per indication
The Australian Register of Therapeutic Goods, usually shortened to the ARTG, is the list of products the TGA has assessed for quality, safety and performance and allowed to be supplied here. A registration applies to a specific product and to the specific indications it was assessed for, and the same active ingredient can appear in more than one registered product with different approved indications for each.
Type 2 diabetes and weight management are separate registrations
A product registered in Australia for type 2 diabetes is not automatically registered for chronic weight management, and the reverse is also true. Coverage that treats the two as one category misstates the Australian position.
Approved overseas is not approved here
Regulatory decisions in other countries do not carry across. Several substances discussed publicly as though they were available treatments are not on the Australian Register of Therapeutic Goods at all.
How these medicines may be discussed
Australian law prohibits advertising prescription medicines to the public, except in limited circumstances. That is why this page explains what testing shows rather than which medicine to ask for, and why it names no products.
Framework
Four different jobs blood tests do
Most confusion about testing on these medicines comes from collapsing four separate jobs into one question. They answer different things, happen at different times, and are ordered by different people.
1. Baseline risk assessment
Testing before treatment starts describes where your metabolic health sits. This is about you rather than about the medicine, and it is useful whether or not treatment goes ahead. It is also what gives every later result something to be compared against.
2. Individual clinical monitoring
For type 2 diabetes, Australian general practice guidance sets out HbA1c, or glycated haemoglobin, every three to six months; lipids individualised to risk; a urine albumin-to-creatinine ratio at least annually, which is a urine test rather than a blood test; and kidney function, reported as creatinine and estimated glomerular filtration rate or eGFR, where clinically indicated. That schedule follows the condition, not the medicine.
3. Investigating a suspected adverse effect
If a specific symptom appears, targeted tests can help investigate it. This is diagnostic work driven by the symptom, not a routine screen, and it usually happens alongside examination or imaging rather than instead of them.
4. Research endpoints
Clinical trials measure markers to describe an average effect across a study population. Those measurements answer a research question. They are not a monitoring schedule for an individual, and reading them as one leads to testing that changes nothing.
Testing
What blood tests can show
Blood tests describe the body around a treatment. Read alongside a clinician, they can show:
What results can describe
- Where your metabolic health sat before treatment started, which is the reference point every later result is compared against
- How markers your doctor already follows for the underlying condition, such as HbA1c, lipids, urine albumin, and kidney function, move over time
- Whether a specific symptom has a laboratory correlate worth investigating further
- Whether something unrelated has appeared that would change clinical decisions
- Trends across repeat tests, which are usually more informative than any single result read on its own
Used in routine clinical care
Markers an Australian doctor may already be tracking for the underlying condition, independent of any single medicine.
- HbA1c
- Lipids
- Urine albumin-to-creatinine ratio
- Kidney function (creatinine and eGFR)
Measured as trial endpoints
Markers reported in clinical trials to describe an average effect across a study population. A trial endpoint is not a monitoring schedule.
- hs-CRP, a marker of low-grade inflammation, reported as a secondary endpoint in weight-management trials
- Amylase and lipase, enzymes made by the pancreas, reported as observed changes in trials
Discussed without established use here
Markers that circulate in online discussion but have no established role in this specific context.
- ApoB
- Lipoprotein(a)
- Fasting insulin
- HOMA-IR
- Calcitonin
If you want to go marker by marker
- Fasting insulin test AustraliaFasting insulin is one of the earliest markers to move in metabolic health, and it often shifts while glucose and HbA1c still read inside their reference ranges.
- HOMA-IR AustraliaHOMA-IR is calculated from fasting glucose and insulin on the same draw. A worked example of a number that only means something alongside another number.
- hs-CRP test Australiahs-CRP appears above as a trial endpoint. This is what it actually measures, and why when you take the sample changes the answer.
- Preventative blood test AustraliaWhat a general preventative panel in Australia contains, and what Medicare does and does not fund for someone without symptoms.
Testing
What blood tests cannot show, and what does
This is the more useful half of the page, and the half most often left out. Each limit below is followed by what actually answers the question, because in every one of these cases something does.
What results cannot settle on their own
- Whether a medicine is working. In a large cardiovascular outcomes trial the benefit did not track the change in HbA1c, so a marker moving is not proof of benefit. What answers it is the outcome treatment was started for, judged clinically: for type 2 diabetes Australian guidance follows HbA1c on a three to six month cycle alongside the rest of the clinical picture, and where the reason for treatment is weight, the measurement is weight.
- Whether sudden vision loss or another eye problem has occurred. There is no blood test for this. Examination answers it: the TGA advises that existing risk can be assessed by an optometrist or ophthalmologist, and Australian general practice guidance advises making sure retinal screening is up to date before starting for people whose HbA1c is well above target or who have a history of retinopathy.
- Whether gallbladder disease has developed. That is an imaging finding. Australian general practice guidance describes no role for routine ultrasound scanning unless relevant symptoms or signs appear, so the symptom is what prompts the scan that answers it.
- Whether raised pancreatic enzymes mean disease. Amylase and lipase, enzymes made by the pancreas, commonly rise on these medicines in people who do not have pancreatitis, and elevations alone do not predict it. What settles the question is the clinical picture, usually severe abdominal pain, investigated with imaging.
- How much of any weight change came from fat and how much from lean mass. No blood marker for this is named in Australian product information or in Australian general practice guidance, and trials used body-composition scanning instead. Australian product information for the registered GIP and GLP-1 medicine does state that body weight reduction is mostly due to reduced fat mass.
- What is actually in a product obtained outside the regulated pathway. TGA laboratory testing of several imported weight-loss products found they contained no GLP-1 at all. Testing a person does not test a product; only laboratory analysis of the product itself answers that.
Monitoring
Why there is no standard GLP-1 panel
Search for this and you will find plenty of pages listing the panel you supposedly need on a GLP-1 medicine. In Australia that panel does not exist. There is no single recurring set of tests that everyone on these medicines is expected to have, and nothing in Australian guidance defines one.
Australian product information is the document a medicine is registered with, approved by the TGA and written for prescribers. For the registered GIP and GLP-1 medicine it carries a heading for effects on laboratory tests, and what it records underneath is that no information is available. That is not an oversight. It is the regulator’s own statement that the question of what this medicine does to laboratory results has no answer on file.
The clearest laboratory instruction anywhere in that document is narrow and symptom-driven: monitor kidney function when treatment is starting or changing in people who already have kidney impairment and who report severe gastrointestinal effects. The reasoning is stated plainly. Vomiting and diarrhoea can cause dehydration, and dehydration can worsen kidney function. It is a response to something happening, not a date in a calendar.
Australian general practice guidance goes further and describes no role for routine testing of pancreatic enzymes unless pancreatitis is suspected, and no role for routine ultrasound unless relevant symptoms or signs appear.
This is why marker lists found online rarely match what an Australian GP orders. Some of those lists are trial endpoints. Some are marketing from overseas laboratories. Neither one is a monitoring plan.
In practice
What a GP conversation actually covers
If there is no standard panel, what does a sensible conversation look like? Australian guidance is not silent here. It is just organised around the person and the condition rather than around the medicine, which is why it does not read like a checklist.
These are the things that guidance actually addresses, so a reader knows what is on the table rather than guessing.
Why treatment was started
This sets everything else. Australian general practice guidance follows the condition being treated, so the reason for treatment decides which markers get tracked and how often. Type 2 diabetes and chronic weight management are different registered indications and they generate different follow-up.
What is already being tracked
For type 2 diabetes, Australian guidance describes HbA1c every three to six months, lipids individualised to cardiovascular risk, a urine albumin-to-creatinine ratio at least annually, and kidney function where clinically indicated. Most of that testing exists already and continues whether or not a medicine in this class is added.
Anything worth checking before starting
Australian general practice guidance names retinal screening for people whose HbA1c is well above target or who have a history of retinopathy, and describes caution where there is a history of pancreatitis or of severe gastro-oesophageal problems. Those checks are about the person’s history rather than about routine surveillance.
What to do if severe gastrointestinal symptoms appear
This is the one place Australian product information gives a clear laboratory instruction, and it applies to people who already have kidney impairment and who report severe gastrointestinal effects while treatment is starting or changing. Knowing that in advance is more useful than a standing test schedule.
What is deliberately not on the list
Australian general practice guidance describes no role for routine pancreatic enzyme testing unless pancreatitis is suspected, and no role for routine ultrasound unless relevant symptoms or signs appear. An absence in guidance of this kind is a considered position rather than a gap someone forgot to fill.
What is not a blood test at all
Some of what guidance does describe is not pathology. Retinal screening is an eye examination. Gallbladder disease is an imaging finding. Australian general practice guidance also notes a mild reversible rise in heart rate on this class, averaging two to three beats per minute, which it describes as not appearing to have clinical implications.
This section describes what Australian guidance covers. It is not a recommendation for any particular person, and which tests an individual needs is a matter for the doctor who prescribed treatment. The point is that a conversation can start from what is actually established rather than from a marker list found online.
Safety
Which symptoms are not blood-test questions
Some of the safety questions people bring to a blood test are not blood-test questions at all. Knowing which is which is what stops a normal result being read as reassurance.
Sudden vision loss
In July 2026 the TGA published safety advice about a rare but severe eye disorder reported with this class. Its advice is ophthalmic throughout: existing risk can be assessed by an optometrist or ophthalmologist, and sudden loss of vision, including partial loss, should be urgently referred for ophthalmological examination. The TGA also advises consumers who notice changes to stop using the medicine and seek prompt medical attention. No blood test appears anywhere in that advice, and a normal blood result is not reassurance.
The eye signal is not uniform across the class
The TGA advisory committee that reviewed the evidence considered it may support the signal for one active ingredient in the class but not for others. Warnings were applied at class level, but the underlying finding was not the same for every medicine. Coverage that treats this as a settled class-wide effect overstates it.
Severe or persistent abdominal pain
Severe abdominal pain that does not settle needs medical assessment rather than waiting for a scheduled test. Australian product information states that elevations in pancreatic enzymes alone are not predictive of acute pancreatitis, so diagnosis needs the symptom, and usually imaging, as well.
Vomiting, diarrhoea and dehydration
Prolonged vomiting or diarrhoea can affect hydration and kidney function. This is the one situation where Australian product information gives a clear laboratory instruction, and it is triggered by the symptom rather than by a schedule.
Products obtained outside the pharmacy system
Products supplied outside the regulated pathway have not been assessed by the TGA for identity, purity, or strength. The TGA has warned about imported unapproved peptide products, and its laboratory testing of several imported weight-loss products found no GLP-1 present at all. No blood test on a person tells you what was in the vial.
FAQ
Frequently asked questions
- What do GLP-1 and GIP actually do in the body?
- They are the two main incretin hormones, released by the gut in response to food. Australian sources describe their effects as stimulating insulin secretion in a glucose-dependent way, reducing glucagon and the glucose the liver makes itself, slowing how fast the stomach empties, and acting on the brain regions that regulate appetite. These medicines act at the same receptors.
- What are the most common side effects of GLP-1 and GIP medicines?
- Gastrointestinal, by a wide margin. In the Australian weight-management trials, pooled across treatment arms, nausea affected 27.5 per cent against 8.5 per cent on placebo, diarrhoea 20.9 against 7.8, constipation 13.6 against 5.2, and vomiting 10.8 against 2.2. Product information records these as mostly mild or moderate, more frequent while treatment is being stepped up, and decreasing over time.
- Do I need a special blood test on a GLP-1 medicine in Australia?
- There is no standard panel and no defined monitoring product that everyone on these medicines is required to have. Australian doctors order tests based on your own health history and the condition being treated, so two people on the same medicine can reasonably have different tests at different intervals.
- What blood tests should you have on a GLP-1 medicine?
- That is a question for the doctor who prescribed it, because the answer follows your history rather than the medicine alone. For type 2 diabetes, Australian guidance describes HbA1c every three to six months, lipids individualised to risk, urine albumin at least annually, and kidney function where indicated.
- Can blood tests show if a weight-loss injection is working?
- No. In a large cardiovascular outcomes trial, the benefit seen did not track the change in HbA1c, so a marker moving is not proof a treatment is working. Response is judged clinically, against the outcome the treatment was prescribed for.
- How do doctors tell whether a GLP-1 medicine is working?
- Clinically, against the reason it was prescribed, rather than from a single marker. In a large cardiovascular outcomes trial the benefit did not track the change in HbA1c. For type 2 diabetes, Australian guidance follows HbA1c every three to six months alongside the wider clinical picture. Where weight is the reason for treatment, the measurement is weight itself.
- Can a blood test rule out eye problems from GLP-1 medicines?
- No. The TGA safety advice on this is ophthalmic throughout: risk is assessed by an optometrist or ophthalmologist, and sudden vision loss should be urgently referred for eye examination. A normal blood result is not a reason to wait.
- Should I have pancreatic enzymes checked while on treatment?
- Australian general practice guidance describes no role for routine testing of pancreatic enzymes unless pancreatitis is suspected. Amylase and lipase commonly rise on these medicines without disease being present, which is why an isolated raised result is difficult to interpret.
- Are markers from clinical trials the same as monitoring tests?
- No. Trial endpoints are chosen to measure an average effect across a study population and to answer a research question. They are not designed as a personal monitoring schedule, and treating them as one leads to testing that changes nothing.
- Does Hemexa prescribe or supply GLP-1 medicines or peptides?
- No. Hemexa does not prescribe, dispense, or supply any medicine or peptide. Hemexa is an Australian preventative blood-testing membership that helps people track their own results over time, and treatment decisions stay with your own doctor.
About this page
Who publishes this page
Hemexa is an Australian preventative blood-testing membership. What we actually do is turn repeat pathology into trends a person can read over time and take to their own doctor, which is why this page keeps returning to the point that a single result matters less than the direction it is moving. This page exists because people ask what testing contributes when they are on these medicines, and an honest answer has to include the things testing cannot do, including some this company sells.
What Hemexa is
- An Australian membership for preventative blood testing and tracking results over time
- A platform that turns repeat pathology into trends a person can discuss with their own doctor
- The publisher of this educational explainer
What Hemexa is not
- Not a prescriber. Hemexa does not prescribe GLP-1 medicines, GIP medicines, or any other medicine.
- Not a pharmacy, and not a supplier of medicines or peptides.
- Not a clinic, and not a route to treatment or access.
How this page is maintained. Last reviewed 15 August 2026.
- Written by
- The Hemexa editorial team. A company publication, so no individual byline.
- Next review triggered by
- A TGA safety communication or product information change affecting the GLP-1 or GIP class, an update to the RACGP and Diabetes Australia handbook, or a change to Australian advertising requirements.
- Sources
- Every factual claim traces to a numbered primary source below: Australian regulators, the Poisons Standard, general practice guidance, and named clinical trials. Where a regulator has since updated its advice, the regulator page is authoritative.
- Scope
- What blood testing can and cannot show. This page does not recommend, supply, or help anyone obtain a medicine, and it names no products.
Nothing here is medical advice. Read the health disclaimer, and take any question about your own treatment to your doctor.
Sources
References
Primary sources, with the date each was accessed. Where a regulator has updated advice, the regulator page is authoritative over this summary.
Therapeutic Goods Administration. GLP-1 RAs and rare, but severe, eye disorders. Safety alert, 23 July 2026. Accessed 15 August 2026.
Therapeutic Goods Administration. GLP-1 RAs and rare vision disorder. Medicine Safety Update, 23 July 2026. Accessed 15 August 2026.
Ng E, Shaw JE, Wood A, Maple-Brown LJ, Hare MJL. Glucagon-like peptide-1 receptor agonist (GLP1-RA) therapy in type 2 diabetes. Australian Journal of General Practice, July 2022, volume 51 number 7, pages 513 to 518. Accessed 15 August 2026.
Royal Australian College of General Practitioners and Diabetes Australia. Management of type 2 diabetes: a handbook for general practice. Updated 19 May 2026. Accessed 15 August 2026.
Therapeutic Goods Administration. Australian Public Assessment Report product information for tirzepatide. Published 20 September 2024. Accessed 15 August 2026.