In recent years, GLP-1 medications such as Ozempic, Wegovy, and Saxenda have moved rapidly into the public spotlight, reshaping conversations around weight management. For some people, these medications can serve as a valuable adjunct to lifestyle change — helping to enhance weight loss and metabolic outcomes when used appropriately.

As with any medication, it’s important to weigh the potential benefits against the risks and consider each person’s individual situation. GLP-1 receptor agonists work by slowing stomach emptying, reducing appetite, and regulating blood sugar — and in doing so, they can influence almost every system in the body.

If you’re considering or already using a GLP-1 medication, here’s what you need to know to protect your health and achieve sustainable results.

The Common (and Manageable) Side Effects

The most frequent side effects of GLP-1 receptor agonists are gastrointestinal — nausea, bloating, constipation, or diarrhoea — particularly when first starting or increasing the dose. These symptoms usually improve with time.

Eating slowly, avoiding large or high-fat meals, and staying hydrated can make a big difference. Less common effects include burping, reflux, and abdominal discomfort. Rarely, people may experience gastroparesis (delayed stomach emptying) or intestinal blockage, especially if they already have digestive issues.

Gallbladder and Pancreas: What We Watch For

Because GLP-1s slow digestion and can lead to rapid weight loss, they slightly increase the risk of gallstones and gallbladder inflammation. This is more likely if you’ve had gallstones before or lose weight quickly.

Pancreatitis (inflammation of the pancreas) is another rare but recognised complication. Seek medical review if you experience severe abdominal pain that doesn’t settle, particularly if it radiates to your back.

Eyes and Vision: Understanding the Evidence

Recent media coverage has raised concern about a possible link between GLP-1 medications and vision loss — specifically a condition called non-arteritic anterior ischemic optic neuropathy (NAION).
So far, large studies show that this complication is very rare, and rates are not statistically higher than in non-users. A few observational reports suggest a possible association, but the overall risk remains extremely low.

If you experience sudden visual changes, seek urgent medical review. At this stage, there’s no evidence to suggest people should avoid or stop treatment based on this concern alone.

The Muscle Factor: Why Strength Matters More Than the Scale

When people lose weight — by any method — they lose a combination of fat, water, and muscle. Because GLP-1s can produce significant weight loss, the loss of lean muscle can also be substantial.

Muscle is crucial for metabolism, strength, and long-term weight stability. Less muscle means a lower metabolic rate and a greater risk of regaining fat once treatment stops.

Protect your muscle:

• Aim for resistance exercise at least three times a week (minimum 60 minutes each session).
• Include adequate dietary protein at each meal.
• Work with a GP, exercise professional, or dietitian who understands body-composition goals, not just weight loss.

Nourishment, Not Neglect: Preventing Nutrition Deficiencies

Many people on GLP-1s find their appetite drops dramatically — sometimes to the point of eating less than 1200 calories per day. While that may sound effective, it can quickly lead to nutrient deficiencies, especially if meals are skipped or limited to small, repetitive foods.

Deficiencies in iron, vitamin D, B12, calcium, magnesium, zinc, and fat-soluble vitamins (A, E, K) are among the most common concerns.

Practical steps:

• Prioritise nutrient-dense meals, not just smaller portions.
• Consider a daily multivitamin if your intake is low.
• Have your vitamin D, B12, and iron levels checked periodically.
• Seek advice from a registered dietitian for a personalised plan.

 Energy, Mood, and the Hidden Cost of Skipped Meals

GLP-1s suppress hunger so effectively that some people forget to eat. Over time, this can lead to energy deficiency, fatigue, low mood, and even bone density loss.

Think of food as fuel, not an optional extra. Even if you’re not hungry, aim for regular, balanced meals to stabilise energy, hormones, and mood.

When Appetite Disappears: Recognising Eating-Disorder Risk

Because these medications blunt appetite, they can sometimes trigger or worsen restrictive eating patterns in people who are vulnerable. Anyone with a history of disordered eating or body-image concerns should approach GLP-1 use with professional support.

If you notice fear around food, excessive focus on weight, or a loss of enjoyment in eating, it’s worth seeking help early — your GP, psychologist, or dietitian can guide you toward safe and sustainable habits.

Long-Term Use and the Challenge of Coming Off

Studies show that maintaining weight loss with GLP-1 therapy usually requires continued, long-term use. Once treatment stops, appetite and weight typically rebound — in many cases, most or all weight is regained within a year.

At present, the cost of long-term therapy is not subsidised in New Zealand, making indefinite use economically unfeasible for most people.

If you’re planning to stop treatment, it’s best to taper gradually under medical guidance, with a plan to support your metabolism and eating patterns through the transition. Continuing resistance exercise, prioritising protein, and maintaining structured meals can help minimise rebound weight gain.

The Bottom Line: Empowerment Through Knowledge and Support

GLP-1 medications can be helpful when used carefully— but they’re not a shortcut or a stand-alone fix. The best results come when medical treatment is combined with balanced nutrition, resistance exercise, and attention to whole-person wellbeing.

At ERH Associates, our goal is to help people understand the bigger picture — how to achieve healthy, sustainable weight loss while preserving muscle, mood, and metabolic health.

We’re also developing our Go Lite program, designed to support confident, evidence-based, and sustainable body transformation — so watch this space for more details in 2026. 

Understanding both sides of the needle — the promise and the precautions — is the key to long-term success.