How do Weight Loss Medications work

How Do Weight Loss Medications Work?

Weight Loss Medications including oral and injectable medications work in different ways to reduce or control your appetite. These Medications should be prescribed by a doctor and taken with a combination of a healthy diet, healthy eating behaviours and regular physical activity.


Oral Tablets - Metformin, Duromine,  Contrave, and Topiramate

These Medications are taken as an oral tablet and work in different ways according to the particular medication. Generally, these medications reduce a patient's appetite and may reduce cravings.


Injectables (GLP1 Agonist) - Trulicity, Saxenda, Ozempic, Wegovy, and Mounjaro

These injectable medications mimic certain GUT Hormones (Hormone GLP1) that control appetite and how we feel when we eat. They often cause patients to snack less and eat smaller portions.

What are the Advantages of Weight Loss Medications?


The benefits of Weight Loss/Anti-Obesity Injectable Medications (GLP1 Agonist) such as Ozempic, Wegovy, Mounjaro, Saxenda and Trulicity may have the following effects on your body. Results will differ depending on the individual.


  • Decreased appetite
  • Decreased food intake
  • Increased Satiety
  • Decreased body weight
  • Increased Insulin
  • Decreased hyperglycaemia
  • Increased Insulin sensitivity
  • Decreased gastric emptying - slower emptying of stomach


How do Anti-Obesity Medications benefit your health?

Anti-Obesity Medications (GLP1 Agonist - Ozempic, Wegovy, Mounjaro, Saxenda and Trulicity) may have the following benefits to you health.  Benefits will differ depending on the individual.


  • Decreased death from cardio-vascular disease
  • Decreased incidence of heart attack
  • Decreased incidence of stroke
  • Decreased blood pressure
  • Decreased fatty liver disease
  • Decreased inflammation
  • Decreased body weight


What are the disadvantages of Weight Loss Injectable Medications (GLP1 Agonist)?

There are a number of disadvantages of using Weight Loss/Anti-Obesity Medications which will vary depending on the type of medication and on the individual. The most common disadvantages of using these types of drugs are:


  • Not PBS listed - Most Anti-Obesity Medications are not PBS listed and carry a significant cost
  • Cost - The high cost associated with taking Anti-Obesity Medications long term often leads to many patients having to stop these medications
  • Weight Regain  - Many patients regain their lost weight within 12 months of ceasing medications
  • Effect wears off - As with certain medications, the effect of Anti-Obesity Medications may diminish over time in some patients
  • Not sustainable - Up to 1/3 patients cease these medications after 1 month in some practices due to cost or side effects & up to 2/3 patients cease after 3 months in some practices due to cost or side effects
  • Not managed by a Doctor - Patients are more likely to cease medications if not prescribed or managed by a specialist
  • Side Effects - Anti-Obesity Medications may need to be ceased if certain side effects occur



When do Weight Loss Injectable Medications need to be avoided?

Please consult your doctor before taking any type of medication. Anti-Obesity Medications should be avoided or taken with caution, if you present with the following:


  • Medullary Thyroid Carcinoma, MEN2
  • History of Pancreatitis
  • Severe GI disorders (eg. Gastroparesis)
  • Pregnancy


What are the possible side effects of Anti-Obesity Injectable Medications?

As with any medication, there are possible adverse reactions or side effects associated with taking Anti-Obesity drugs. Please consult your doctor if any of these side effects occur.


  • Nausea, Vomiting, Diarrhoea, Early Satiety
  • Pancreatitis
  • Gallstones
  • Delayed Gastric Emptying
  • Thyroid C cell tumours
  • Acute Kidney Injury
  • Hypoglycaemia
  • Blurred Vision