Long-Term Use of Weight Loss Medication: Risks and Monitoring
How long weight loss medication is used is a decision made with a doctor or nurse practitioner and checked at regular reviews. Australian guidance expects treatment to be needed over the long term, and says that data on its long-term harms, and on how well it works over the long term, are still limited (Obesity Evidence Hub). Outcomes vary between individuals.
On this page
- Key Points
- How Long Weight Loss Medication Is Used
- What Is Known, and What Is Not Yet Known
- Side Effects and Risks to Discuss Over Time
- How Long-Term Use Is Monitored
- What You Can Do Between Reviews
- Diet and Physical Activity Stay Part of the Plan
- Talking to a Practitioner at Burst Health
- Frequently Asked Questions
Key Points
Obesity is a chronic condition that usually needs long-term care, and medication is one part of that care.
Some side effects only become known after a medicine has been in wide use.
Possible issues to discuss include gut side effects, pancreatitis, kidney stones, glaucoma and changes in mood, depending on the medication.
Regular reviews check how treatment is going, how you are tolerating it and whether it still suits you.
A healthy diet and regular physical activity stay part of the plan the whole time.
How Long Weight Loss Medication Is Used
Obesity is a chronic condition with periods of relapse and remission, and it needs lifelong management (Royal Australian College of General Practitioners). Management here means long-term care with several parts, not medication alone.
After even modest weight loss, the body makes hormonal changes that increase hunger and reduce energy use. The hormone changes that increase hunger last at least six years, and probably for life (Proietto, 2022).
Any effect of weight loss medication lasts only while it is used, and stopping it commonly leads to weight regain (Obesity Evidence Hub). That is the reason behind the long-term expectation, and the reason each review asks whether treatment still suits you.
For what results can look like over time, see how much weight you can realistically expect to lose.
What Is Known, and What Is Not Yet Known
Some trials described in Australian guidance followed people for 2 to 4 years. There is also a limit to what any trial can show. Trials generally have strict rules about who can take part and include a limited number of people, so new side effects are often found only after a medicine is used more widely. Some side effects are so rare that thousands of people can use a medicine for a long time before they are identified (Therapeutic Goods Administration, TGA).
Side Effects and Risks to Discuss Over Time
Not every issue applies to every medication. Which ones matter for you depends on the option being considered and on your health.
| What to discuss | Why it matters |
|---|---|
| Gut side effects | Nausea, constipation and diarrhoea are common |
| Pancreas | Pancreatitis is a listed side effect |
| Kidneys | Kidney stones are a listed side effect |
| Eyes | Glaucoma is a listed side effect |
| Sleep and energy | Insomnia and fatigue are listed side effects |
| Mood | Some options may increase the risk of depression |
| Eating enough | Appetite can fall, so nutrients need attention |
The table uses the side effects that healthdirect lists for weight loss medication in general. It is not a complete list, and the leaflet for your own medication has more.
A few points sit behind the table:
Side effects can change over time. Some ease after a medicine has been taken for a while, while others do not appear straight away and develop later.
Eating less can mean fewer nutrients. These medications can reduce appetite, so it matters to eat enough food and nutrients each day. For some people, reduced appetite may lead to an eating disorder.
Procedures need planning. With some options, you may need to go without food for longer before some medical procedures, so tell your doctor or nurse practitioner about all your medicines before surgery or a procedure.
Diabetes adds points to discuss. Some weight loss medications are also used to help manage type 2 diabetes. If you live with diabetes, read the type 2 diabetes guide.
How Long-Term Use Is Monitored
A dose that suits one person could cause severe side effects in another. People using weight loss medication are routinely monitored for side effects and for their response to treatment, and a different option can be tried if the first is not tolerated or is not helping (Proietto, 2022).
Regular follow-up checks how treatment is going, how well you are tolerating it, any side effects, and whether you are taking it as directed (Obesity Evidence Hub). At a review, it helps to raise:
any side effect, including one that seems minor or started well into treatment
any change in mood, sleep or eating patterns
any new medicine, including over-the-counter, herbal and supplement products
any new health condition, planned surgery or procedure
plans for pregnancy or breastfeeding, because some medicines should not be used at those times
Read the Consumer Medicine Information
Every medicine that needs a script has a Consumer Medicine Information (CMI) leaflet with information on side effects, and your pharmacist should offer it when you start a new medicine. A newer medicine may show a black triangle on its leaflet. The triangle is a reminder to report side effects.
What You Can Do Between Reviews
You do not need to wait for a review to raise a concern. Questions worth asking your doctor, nurse practitioner or pharmacist (healthdirect):
What are the possible side effects, and does this medicine have any serious ones?
How often do these side effects happen?
What can I do to lower my risk of side effects?
What should I do if I think I am having a side effect?
You can also call healthdirect on 1800 022 222 to speak with a registered nurse about a possible side effect.
Report a Side Effect to the TGA
Anyone can report a side effect, for themselves or for someone else, and you do not need to be certain the medicine caused it. Your GP, nurse practitioner or community pharmacist can help you make a report. Every report adds to what is known about a medicine over time.
When to Get Help Straight Away
Any side effect that seems serious needs a doctor at once. In an emergency, call triple zero (000) for an ambulance.
Sudden, severe pain in the upper belly that may spread to your back, chest or sides can be a sign of pancreatitis. Go to the nearest emergency department.
Diet and Physical Activity Stay Part of the Plan
Weight loss medication is used together with healthy lifestyle changes, not in place of them. The everyday basics are the same at every stage of treatment:
a healthy diet built on a wide variety of foods from the five food groups, and plenty of water (Eat for Health)
moderate to vigorous physical activity for 30 minutes or more on most days, and muscle-strengthening activities on 2 or more days a week (Department of Health, Disability and Ageing)
A dietitian can help you get the nutrients your body needs while your appetite is lower. For practical steps, read a realistic guide to losing weight, what a calorie deficit is and how many steps a day can help.
Talking to a Practitioner at Burst Health
Burst Health offers phone consultations with Australian doctors or nurse practitioners. A practitioner needs to speak with you before any treatment is approved. If you are a Burst Health patient, raise any side effect or question about long-term use with a practitioner. For how this fits into a wider plan, see how medical weight loss programs work. Outcomes vary between individuals.
Long-term use is reviewed rather than set once, and Burst Health provides medical weight loss plans online with regular reviews by an Australian-registered doctor or nurse practitioner, so check whether you are eligible.
Frequently Asked Questions
Can you take weight loss medication for life?
It depends on regular review. Australian guidance expects weight loss medication to be needed over the long term, but the evidence on long-term use is still limited. At each review, your doctor or nurse practitioner looks at your response, any side effects and your health, and decides with you whether continuing still suits you.
How long can you stay on weight loss medication?
It depends on the option and on you. How long you may need treatment is one of the things your doctor or nurse practitioner discusses with you when choosing an option, along with how often it is taken, the cost, possible side effects, your medical history and your preferences. One approved option is for short-term use only.
Which organs can weight loss medication affect?
Depending on the medication, listed side effects include pancreatitis (the pancreas), kidney stones (the kidneys) and glaucoma (the eyes). A common type of side effect involves the gut, such as nausea, constipation or diarrhoea, and some options can affect mood. Your practitioner can explain which of these apply to the option being considered.
What does the black triangle on a medicine mean?
A black triangle on a medicine's information leaflet means the medicine is new in Australia or is being used in a new way. Medicines stay in this scheme for at least 5 years from first supply. It is a reminder to report side effects. It does not mean a problem is known.
Where can I report a side effect?
You can report a side effect directly to the Therapeutic Goods Administration (TGA), or ask your GP, nurse practitioner or community pharmacist to help you report it. A suspicion that the medicine caused the problem is enough to make a report. Also tell the practitioner who manages your treatment, so they can review your plan.
Medical weight loss plans, online
In three steps.
- 1Answer a quick questionnaireOnline, no appointment, no in-person visit.
- 2A practitioner reviews itAn Australian-registered doctor or nurse practitioner decides whether treatment is suitable for you.
- 3Start your planIf treatment is suitable, you start your plan with the practitioner supporting you throughout.
References
Markovic TP et al. The Australian Obesity Management Algorithm (July 2024).
Proietto J. Medicines for long-term obesity management. 2022.
Therapeutic Goods Administration (tga.gov.au). The Black Triangle Scheme.
Therapeutic Goods Administration (tga.gov.au). Overview of adverse event reporting for medicines, and Reporting adverse events for consumers.
Eat for Health (NHMRC). Australian dietary guidelines 1 - 5.
This article is general information only and does not replace individual medical advice. Please speak with a registered Australian healthcare practitioner about your own circumstances.