A medical expert has issued a caution over weight loss injections as their use continues to rise across the United States.
GLP-1 medications such as semaglutide and tirzepatide were first developed to help treat type 2 diabetes, but they are now also widely used for weight management and related health conditions.
Recent polling suggests that about one in eight U.S. adults is currently taking a GLP-1 drug, while nearly one in five says they have used one at some point. Demand has surged alongside interest in newer obesity treatments and broader awareness of their weight-loss effects.
As access to the injections becomes more widespread, specialists have been highlighting the possible downsides and health risks linked to them, particularly when they are used without proper medical supervision or without enough attention to diet and exercise.
Dr Federica Amati, a medical scientist and nutritionist, recently discussed the issue during an appearance on ITV’s This Morning, where she shared a message she believes people need to pay attention to.
She stressed that the injections were never intended purely as weight loss treatments, and said they should not be viewed as a simple fix or a guaranteed solution for everyone.
“We’re trying to help people achieve better body composition or improve their blood glucose control,” she said.
“And increasingly they have an effect on heart health, kidney health. We’re seeing more applications for this. But this is not a lifestyle drug.
“It’s actually a medicine that demands you to improve your lifestyle and your nutrition because otherwise you really run the risk of malnutrition and of having nutrient deficiencies, and of losing muscle mass in the long term.”
Dr Amati said she strongly supports medication when it is used properly because these drugs can be effective, but added that patient wellbeing must remain the priority.
Dr Amati continued: “The people who take these medicines need to be screened appropriately. They need to be prescribed to the right people. It’s not for everybody to take these.”
She also said that people using the injections need guidance around diet and habits to reduce risks including loss of lean mass and shortages in key nutrients.
According to Dr Amati, strength-based exercise plays an important role for anyone taking these medications, because maintaining muscle and bone health should be a major focus.
Health experts say this is especially important because rapid weight loss can reduce not just fat, but also lean tissue if protein intake, resistance training and overall nutrition are not being managed carefully.
Doctors also caution that the most common side effects of GLP-1 medicines are gastrointestinal, with nausea, vomiting, constipation, diarrhea, reflux and abdominal discomfort frequently reported. In some people, severe stomach symptoms can lead to dehydration and, in rare cases, kidney problems or gallbladder issues.
During the same TV segment, she explained that the side effects most often reported with weight loss jabs are constipation, reflux, nausea and vomiting.
“They’re not life-threatening by any stretch, but they’re not nice to live with,” the healthcare professional continued.
Host Josie Gibson also mentioned knowing people who had slimmed down after taking the drugs, but had also begun losing hair.
“I wouldn’t say their nutrition was the best, they don’t look healthy,” Dr Amati added.
Experts say anyone considering or already taking a GLP-1 medicine should do so under medical supervision, especially if they have diabetes, a history of pancreatitis or gallbladder disease, or if they are taking other medicines that can affect blood sugar. Clinicians also advise regular monitoring, including attention to protein intake, hydration, and signs of excessive or unhealthy weight loss.
While weight loss injections can be an effective tool for some patients, specialists are increasingly urging people to treat them as part of a broader health plan rather than a shortcut, with nutrition, exercise and follow-up care all playing a key role in safer, more sustainable results.