The mindset and practice of treating obesity have evolved beyond diet and exercise. Obesity is now treated as a chronic disease. Weight loss injections are the most recent treatment reaching millions of U.S. adults dealing with obesity; however, not everyone knows the long-term commitment that’s needed for these injections and that stopping them risks regaining the weight.
“It’s estimated that 50% of Americans qualify to use these injections to improve their health and reduce the associated risks of obesity,” said Deborah B. Horn, DO, MPH, an obesity medicine physician at UT Physicians Minimally Invasive Surgeons of Texas (UTMIST) – Bellaire Station, specializing in medical weight loss management.
Although beneficial, it’s important to understand what using these weight loss injections entails and the possible side effects.
Semaglutide and tirzepatide medications
The body makes a natural hormone called glucagon-like peptide-1 (GLP-1), which helps to regulate blood sugar, digestion, and appetite.
“When you eat something, your body releases GLP-1, which sends a message to your brain that there’s food here, triggering the sensation of fullness and decreasing hunger,” said Horn, an associate professor in the Department of Surgery at McGovern Medical School at UTHealth Houston and the medical director of the UT Physicians Center for Obesity Medicine and Metabolic Performance.
Semaglutide and tirzepatide are medications that mimic GLP-1.
The Food and Drug Administration (FDA) has approved two weight loss injections that can be used to treat obesity and two other weight loss injections to treat Type 2 diabetes. There are no generics available for these medications.
How do weight loss injections work?
The difference between the medicine and the body’s natural hormone is how long it triggers the sensation of feeling full.
“The message from the natural GLP-1 released in your body lasts about two minutes, and then it starts breaking down. The signal of fullness from the GLP-1 medications lasts about five days, which helps people manage hunger, cravings, and portion sizes,” said Horn.
Who qualifies for weight loss injections?
The requirement for a weight loss injection prescription is based on body mass index (BMI), which is a calculation used to determine a diagnosis of overweight or obesity. The BMI calculation is based on height and weight.
Qualifying patients must have a BMI of 27 or greater with a comorbidity (another medical condition besides obesity) or a BMI of 30 or greater without a comorbidity.
There are more than 250 comorbidities, with the most common being cardiovascular disease, Type 2 diabetes, hypertension, elevated cholesterol, arthritis, lymphedema, and depression. GLP-1 medications are also approved for cardiovascular disease, obstructive sleep apnea, and metabolic dysfunction-associated steatotic liver disease, formerly known as fatty liver disease when a patient also has obesity.
Long-term use
Reaching a weight loss goal does not mean an end to the medication.
“Many people think they should just take the medication, get to a goal weight, and then go off the medication,” said Horn.
The GLP-1 injections approved by the FDA have been approved for long-term use because obesity is now treated as a chronic progressive disease.
“The medication supports your body’s physiology, similar to how high blood pressure or diabetes medications work. When you take that support away, your physiology will go back to what it inherently does on its own. In the case of obesity, the body is likely to regain weight,” said Horn.
In short, be prepared for long-term use to keep the weight off.
Reducing use after reaching your health goals
For individuals interested in reducing how much medication they take, work with your health care provider to slowly decrease the dose over time.
“If there’s a point at which the weight begins to come back, then return to the last effective dose and stay there,” said Horn.
The injections stay on the same weekly schedule, but with an adjusted dose.
Risks of using weight loss injections
Semaglutide and tirzepatide medications come with health and safety warnings.
The most common side effects include nausea, diarrhea, vomiting, constipation, stomach pain, headache, fatigue, dizziness, heartburn, or a runny nose. These occur in more than 5% of individuals and are usually mild to moderate and temporary.
Serious potential side effects include a risk of developing thyroid tumors or thyroid cancer, which were seen in rodent studies, but no human cases have been reported after more than a decade of using GLP-1 medications for diabetes patients. Pancreatitis can occur in approximately 2-3 out of every 1,000 patients.
“Extensive clinical trials demonstrate these medications are safe and approved by the FDA for long-term use,” said Horn.
How to get started
An important first step in taking weight loss injections is to have a conversation with your health care provider.
“Have that conversation about your choices, what the right decision is for you, and what it means to stay on the medications long term,” said Horn.
Weight loss injections are proven to be an effective tool to treat obesity, but to maintain this healthier weight, be prepared for lifelong medication. “I am thankful to have this option to help patients,” said Horn. “But each patient needs to take the time to understand the best use of these medications for themselves and their overall health.”
