Breaking Down Medications for Weight Loss: Ozempic, Wegovy, and More
An expert explains how medications for weight loss like Ozempic and Wegovy work, their benefits, risks, and who they’re best for.
Medications for weight loss have soared in popularity since 2017, when Ozempic was first approved by the Food and Drug Administration (FDA). There are now nine types of FDA-approved GLP-1 (glucagon-like peptide-1) agonists — a class of prescription drugs for weight loss.
Scientists are also finding new uses for the breakthrough weight-loss drugs, which were originally designed for diabetic and medically overweight patients. Recently, the FDA announced Ozempic can be used to reduce the risk of chronic kidney disease. Wegovy won FDA approval to reduce the risk of heart attacks, strokes, or cardiovascular death, and Zepbound recently became the first drug approved for obstructive sleep apnea.
Research is still early, but the medications may eventually be used for a host of other medical conditions. A new, large-scale study published in the journal Nature Medicine reported that Ozempic and similar medications for weight loss may lower risk of dozens of health conditions, including Alzheimer’s disease, substance use disorders, and mental health conditions. It also found that it increased risk for other conditions, including pancreatitis (an inflammation of the pancreas) and arthritis.
“Weight affects so many chronic medical conditions, including diabetes, high blood pressure, cholesterol, fatty liver, and certain cancers — as well as issues like sleep apnea and osteoarthritis,” says Dr. Mohini Aras, an obesity medicine specialist at NewYork-Presbyterian/Weill Cornell Medical Center. “Our goal with weight loss is to improve these conditions, and even a modest weight loss of 5% to 10% can make a difference.”
Dr. Aras spoke with Health Matters about how drugs like Ozempic and Wegovy work, who should (and shouldn’t) take them, and their risks and side effects.
Dr. Mohini Aras
How do medications for weight loss work?
Dr. Aras: First, it’s important to understand that our brain is designed to defend against starvation and retain our weight. When we lose weight, naturally occurring hormones send a message to our brain to increase hunger and cravings and slow our metabolism down. Our brain even makes our muscles more efficient, so we don’t burn as many calories with the same activity; this is a starvation response. As a result, people tend to yo-yo: They will lose, regain, lose, and regain weight.
Medications for weight loss activate the hormones that we naturally produce to regulate weight. These medications target appetite and hunger, helping people feel full sooner and stay full longer. They may also impact cravings, thoughts of food, and binge eating.
The first anti-obesity medicines were stimulants that were approved in the late 1950s, and we’ve seen a lot of advances in the field of obesity medicine in the last 10 years.
How are these medicines taken?
Ozempic, Wegovy, Mounjaro, and Zepbound (which all contain the active ingredient semaglutide) are once-weekly injectable medications. They come as a pen, and you do the injection yourself at home. It’s a subcutaneous injection, so you can do it in your upper thigh, in your abdomen, or in your arm, and it’s a tiny needle that is just enough to poke the skin — so it’s not too bothersome for people.
An oral version, Rybelsus (which contains the active ingredient tirzepatide), is taken once a day, typically on an empty stomach when you first wake up. The pills are easier to transport, as opposed to the injectables, which have specific temperature requirements. Both Ozempic and Wegovy may also soon be available in the form of a daily pill, and two recent studies showed that the oral versions are about as effective as the injectables.
How can you get a prescription?
We require a comprehensive medical evaluation, including labs, vitals, and a full medical history. We tailor individual plans for patients, with the foundation being diet and physical activity, and select appropriate weight loss medications that can help support the hard work that they are doing. We also have a team of providers, including registered dieticians, nurse practitioners, and physicians, who aid patients in achieving their health goals.
Patients who have histories of gallbladder disease, pancreatitis, or family histories of medullary thyroid cancer or rare disorders of the endocrine system may not be eligible.
How much do they cost?
These medicines are quite expensive if they’re not covered by insurance — from $900 to $1,400 a month. We have an entire pharmacy team dedicated to processing the authorizations required by insurances to try to obtain these medications for our patients.
Obesity is chronic, so when we start a medication, we have to plan for it long-term. Given the cost of being on these medications, most of my patients wouldn’t be able to afford these drugs without insurance coverage.
Can these medications also help with addiction?
Medications for weight loss improve satiety and reduce cravings. Clinically, many patients do report a reduction in their interest in alcohol — and that’s a type of craving. It’s important to remember that these medicines work while you take them, so the benefit of reduced cravings won’t persist once the medicine is no longer circulating in your body.
How long do patients have to remain on weight-loss medication?
Obesity and type 2 diabetes are chronic medical conditions that require long-term management. I tell my patients to plan for long-term use, which is why cost is important to discuss up front.
What are the side effects of taking medications for weight loss?
These drugs directly act on the gastrointestinal system. One of the ways they work is by slowing the gastric emptying, so the food sits in your stomach longer before it goes into your intestines. That’s how it can make people feel full sooner and stay full longer, but that’s where the side effects come in as well — because food’s sitting there, it can cause some reflux, nausea, a sense of overfullness, diarrhea, or constipation.
The injectable medicines are most potent the first few days after the injection, and that’s when the side effects can be most prominent. In general, we start with the lowest dose and gradually escalate as needed; we always want to use the least amount of medicine possible to facilitate weight loss.
I’ve seen a common misconception that the side effects of drugs like Ozempic are horrible, but, for the most part, that’s not been my clinical experience. The gastric slowing is something that is known about this class of medications and contributes to the gastrointestinal side effects, but for the vast majority of people, they are able to tolerate the medications well. It’s important to reduce portions and eat slowly to mitigate side effects.
Our practice at the Comprehensive Weight Control Center has used these medicines for a long time; we have a lot of tips and tricks that make them more tolerable for patients who are sensitive to the side effects.
What would you say to patients who are interested in these drugs but may be feeling ashamed to ask about them?
Physicians have failed people who struggle with weight for decades. We have told them to eat less and exercise more, and now we know that’s not sufficient for the vast majority of people. Obesity is a chronic disease with several root causes that requires medical management. I would encourage patients to seek more information to understand if they would be good candidates for these medications.