Dr Nick Fuller
Leading Obesity Expert at the University of Sydney and founder of Interval Weight Loss.
Many women over 40 are told weight loss injections are a quick fix, but is that really true?
Marketing and social media often make it sound simple: take a shot, and the pounds will melt away. These messages can be tempting, especially when weight seems harder to shift than it used to.
But like many claims in the diet and weight loss industry, the promise of easy results isn’t fully backed by evidence. Research shows injections can support weight management, but they also come with risks and limitations that matter more as our bodies age.
In this article, we’ll explore how weight loss injections work, what the research says about their safety for women over 40, and the important factors to weigh up before starting treatment. Read on to discover whether they might be the right fit for your health journey.
If you’ve noticed it’s harder to lose weight than it used to be, you’re not imagining things. After 40, several natural changes in the body make weight management more challenging.
Metabolism slows down. Your resting energy expenditure (the calories your body burns just to keep running) gradually decreases with age. That means the same meals and exercise that used to work may no longer give the same results.
Hormonal shifts also play a big role. In women, declining oestrogen levels around menopause can lead to increased fat storage around the abdomen and changes in appetite regulation. Men experience gradual drops in testosterone, which can reduce muscle mass and lower metabolic rate.
Muscle mass itself naturally declines with age, a process called sarcopenia. Less muscle means fewer calories burned, even when you’re active. Combine that with lifestyle factors, like busier schedules, stress, and less sleep, and it’s easy to see why weight loss feels tougher.
Understanding these changes doesn’t mean you’re stuck. It means weight management strategies need to evolve with your body. Later in this article, we’ll look at how weight loss injections fit into this picture, and what actually works versus what’s just hype.
Weight loss injections aren’t a magic bullet, but for women over 40, they can be a helpful tool when used alongside lifestyle strategies. Here’s how they support your body during a stage when metabolism, hormones, and energy levels make losing weight trickier.
Many injections work by targeting appetite hormones, helping you feel full for longer and reducing cravings. This can make a real difference when old eating habits or hormonal changes push you toward snacking or larger portions. By helping you eat less without feeling deprived, these injections create a more manageable and sustainable approach to weight management.
Some injections improve insulin sensitivity, which helps your body handle carbohydrates more efficiently. Better metabolic function can reduce fat storage and make your weight management efforts more effective, particularly if blood sugar swings have been sabotaging your progress. Over time, this can also help stabilise energy levels and reduce the urge to overeat when your blood sugar dips.
Perimenopause and menopause bring shifts in oestrogen and other hormones that often lead to fat accumulating around the midsection. Certain injections can help mitigate these effects, making it easier to manage weight despite natural hormonal changes. This support is especially valuable for women who struggle with stubborn belly fat that doesn’t respond to diet and exercise alone.
Weight loss injections, such as GLP-1 receptor agonists, can support gradual reductions in body weight over several months. In real-world practice, a study of patients taking liraglutide found that weight loss occurred steadily over 3–6 months, though maintaining adherence was key to sustaining results. This steady approach helps make the changes easier to maintain and can reduce the risk of rapid regain. Gradual fat loss also places less stress on the body and supports the preservation of lean muscle, which is especially important as we age.
Beyond weight loss, some injections can improve cardiometabolic markers. This means they don’t just help you shed kilos; they can also support long-term health. For women over 40, addressing these risks early can make a significant difference in preventing chronic conditions later on.
If you’re over 40, it’s natural to wonder whether weight loss injections are safe for your body. After all, hormones, metabolism, and organ function all change with age, and what works in your 20s or 30s may not work the same way now.
Research shows that many modern injections, such as GLP-1 receptor agonists, can be safe for adults when prescribed and monitored by a healthcare professional. They can help manage appetite, improve blood sugar control, and support gradual fat loss.
That said, safety isn’t just about the medication itself. Your overall health, existing medical conditions, and how your body responds individually all play a role. Some women may experience side effects like nausea, digestive issues, or temporary changes in energy levels.
Because every body is different, especially after 40, it’s crucial to work with a qualified healthcare provider. They can assess your risks, monitor your progress, and adjust the treatment plan to suit your needs.
Weight loss injections can be a useful tool, but they aren’t a one-size-fits-all solution. Understanding how they interact with your body is the first step toward making an informed decision.
Weight loss injections can be helpful, but like any treatment, they come with potential side effects. Understanding them is important, especially after 40, when your body may respond differently than it did in younger years.
The most common side effects involve the digestive system. As mentioned earlier, many people experience nausea, vomiting, or general stomach discomfort, particularly when starting treatment. Some may also notice constipation or diarrhoea as their body adjusts. These symptoms often improve over time, but monitoring and dose adjustments with your healthcare provider can make a big difference.
After age 40, preserving lean muscle and bone density becomes increasingly important. Studies of semaglutide show that while it effectively reduces body weight, it may also lead to small decreases in bone mineral density. This highlights the importance of pairing treatment with adequate protein intake, resistance exercise, and a well-rounded lifestyle to support muscle and bone health.
Weight loss injections can slightly increase the risk of gallbladder issues. Rarely, more serious complications such as pancreatitis, thyroid concerns, or vision problems can occur. While these are uncommon, awareness and regular monitoring help ensure any issues are caught early.
Weight loss injections can be a helpful tool for women over 40, but they’re not risk-free. Changes in metabolism, hormones, and muscle mass mean that managing weight requires a thoughtful, personalised approach.
These injections can support appetite control, metabolism, and overall health when used alongside a balanced plan of nutrition, exercise, and lifestyle habits. Working with a qualified healthcare professional ensures the treatment is safe, tailored to your needs, and more effective in the long term.
Wondering what else can help you lose weight more sustainably after 40? Discover metabolism-boosting tips tailored to women 40+, from strength training to smart meal timing, to support your journey safely and effectively. Read this article now.
Dr Nick Fuller is the founder of Interval Weight Loss and is a leading obesity expert at the University of Sydney with a Ph.D. in Obesity Treatment. Dr Fuller is also the author of three best-selling books and his work been published in top ranked journals in the medical field, including JAMA, Lancet and American Journal of Clinical Nutrition.