Treating obesity is always a multidisciplinary process. It requires a combination of healthy eating and regular physical activity.
In some cases, weight loss medications can support these efforts. While they’re not a standalone solution, certain treatments may help manage appetite, improve metabolic health, or enhance the results of lifestyle changes.
So, what medications are available? Let’s take a closer look.
Newer generation medications
These treatments are at the forefront of obesity care and show promising results, especially when combined with lifestyle changes:
GLP-1 analogues (e.g. Saxenda, Wegovy)
These medications mimic a natural hormone that helps regulate appetite and slow digestion. They are administered as daily or weekly injections and must be prescribed and monitored by your doctor. Research indicates that they can support weight loss of 5-15% when used in conjunction with lifestyle changes. Pharmac has recently approved Wegovy, which will be available in New Zealand from July 2025.
GLP-1/GIP combination treatments (e.g. Mounjaro)
These newer medications combine two gut hormones, GLP-1 and GIP, to reduce appetite and improve blood sugar control. Early research suggests that this combination can support even greater weight loss, with some individuals losing up to 20% of their body weight. Although approved overseas for both diabetes and weight loss, these treatments are not currently available in New Zealand.
Bupropion/Naltrexone (e.g. Contrave)
This combination of medications includes Bupropion, an antidepressant that also supports smoking cessation, and Naltrexone, which helps reduce side effects like nausea. Together, they work on the brain’s hunger and reward pathways to reduce appetite and manage cravings. Contrave is taken as a daily tablet and may support weight loss when used in conjunction with a healthy diet and regular physical activity. It is available in New Zealand with a prescription.
Add-on treatments
These medications are not prescribed specifically for weight loss but may provide modest support for those with certain conditions:
Metformin
Metformin is a medication used to treat diabetes, prediabetes, and polycystic ovary syndrome (PCOS). It can assist with weight loss, with studies showing an average reduction of 2 to 3 kg. However, it is not prescribed for people with normal blood sugar levels and is not considered a weight loss medication.
SGLT2 Inhibitors (e.g. Jardiance, Forxiga)
Like Metformin, SGLT2 inhibitors are used to treat diabetes and, in some cases, heart or kidney failure. They are associated with a slight reduction in weight and blood pressure. These medications are not prescribed for weight loss alone and are only suitable for people with specific medical conditions.
Topiramate (Topamax/Topitrim)
Topiramate is an antiepileptic medication that doctors prescribe to help prevent migraines. It may reduce appetite in some people and support weight loss. However, it is considered an off-label treatment for obesity and is not FDA-approved for this purpose.
Older generation medications
These treatments were once more commonly used for weight loss but are now prescribed less frequently due to side effects and the availability of newer alternatives.
Phentermine
Phentermine is a stimulant-based medication that can suppress appetite. In the past, doctors prescribed it short-term for quick weight loss ahead of significant events, which led to its nickname “the wedding pill.” Because it can increase heart rate and blood pressure and may contribute to binge eating, it’s typically not prescribed for longer than three months.
Today, phentermine is used less often due to its side effects and the availability of newer, safer options. With rising ADHD diagnoses worldwide, other amphetamine derivatives are now more commonly used to support focus and regulate eating behaviour.
Orlistat (e.g. Xenical)
Orlistat works by reducing the amount of fat the body absorbs from food. The unabsorbed fat passes through the digestive system, which can cause side effects like bloating, cramping, and oily or loose stools. To minimise discomfort, patients need to follow a lower-fat diet. While Orlistat usage was once common, it’s now prescribed less frequently due to side effects and the availability of alternative treatments.
In summary
Treating weight gain requires a multidisciplinary approach. It’s not just about numbers on a scale. It’s about enhancing your overall health through adjustments to your diet, physical activity, and daily routines.
Medications can support these efforts when used in conjunction with lifestyle changes, but they are not a standalone solution. Medications can support these efforts when used in conjunction with lifestyle changes, but they are not a standalone solution. The most effective approach involves experienced physicians who assess your unique needs and provide safe, evidence-based care.
In next month’s blog, I’ll discuss surgical options (such as bariatric or endoscopic procedures) in more detail and explain how they may also play a role in treatment.
If you’re considering weight loss options, I run a dedicated weight loss clinic every Wednesday at Devonport Health Centre. Together, we can create a plan that suits your lifestyle and goals. Please speak to reception for more details.