Are the New Weight Loss Drugs for Obesity Care Safe?

Anti-obesity medication news is seemingly everywhere — from celebrities causing #Ozempic to trend on TikTok to the various drugs’ availability, benefits and risks being discussed on the nightly news.  

There are a few anti-obesity drugs that have had FDA-approval for a while, but the new approval of the medication Wegovy (a similar drug to the influencer-promoted Ozempic) is making waves. 

Some have praised these medications for their ability to aid weight loss. But there are also concerns about safety, shortages, cost, rebound weight gain and healthcare inequities. Like most things, these drugs are neither all good or bad — and there’s still more for researchers to discover.  

How common is obesity? 

In the U.S., more than 2 in 5 adults have obesity, defined in medicine as a body mass index of 30 or higher. We also know there is stigma around obesity — including in the medical community — with many people believing it is caused by a lack of willpower. But this isn’t true. Obesity is a chronic disease. It’s caused by a mix of genetic and environmental factors and can require a long-term treatment plan that includes a combination of medication, surgery, and behavioral and lifestyle changes. 

Along with the social media buzz, the prevalence and complexity of obesity are reasons these drugs are drawing so much attention. When prescribed by a doctor as a part of an overarching weight management treatment plan, they offer another way to manage and treat obesity. 

Who can take weight loss medication? 

While you may have heard about celebrities taking weight loss medications to stay slim, most of these drugs are only intended for folks with a BMI over 30 or folks with a BMI over 27 and a weight-related medical condition, like hypertension, type 2 diabetes and high cholesterol. 

“These medications are not an option for people that simply want to lose weight to be a certain size,” says Dr. Delilah Strother, a UW Medicine family medicine doctor at Primary Care at Woodinville.  

This is because some of these medications carry serious risks, such as pancreatitis. To help people stay safe and monitor medication use, almost all of these medications must be prescribed by your doctor.  

So, what are the FDA-approved weight loss drugs and how do they work? 

There are six FDA-approved weight loss medications for long-term use to treat obesity.  

Most of these medications result in about 9-10% body weight loss, with the exceptions of Orlistat, which is much less, and Wegovy, which is slightly more at about 15% total body weight loss.  

Orlistat (brand names: Xenical and Alli) 

There are two types of FDA-approved orlistat: Xenical, which has a higher dose and requires a prescription, and Alli, which has a lower dose and is available over the counter at drug stores. Both medications work by reducing the amount of fat you absorb from a meal, Strother says. The unabsorbed fat moves through your body and exits via bowel movements.  

Pros: Both forms of orlistat are taken orally in a pill form before meals, Alli is over the counter and the medications are relatively low cost.  

Cons: “Oily fecal discharge,” Strother says. (Aw, crap.) In addition, orlistat isn’t the best option for folks already eating low-fat diets, and it doesn’t address some of the root metabolic disturbances that can cause obesity, like increased appetite and insulin resistance. 

Side effects: gas, cramps, loose stools and that oh-so-fun fecal discharge.  

Phentermine/topiramate (brand name: Qysmia) 

As the name indicates, this drug is a combination of two medications: phentermine, which suppresses appetite, and topiramate, which is an anticonvulsant that has been shown to decrease appetite and increase the feeling of satiety.  

“Topiramate also has a dopaminergic effect, so it can help with the reward part of eating and reduce cravings. It will make soda taste flat,” says Dr. Laura Montour, an obesity medicine expert at the Center for Weight Loss and Metabolic Surgery at UW Medical Center – Roosevelt. 

When taken together, the drug suppresses your appetite so that you feel fuller for longer. The FDA approved the medication for chronic weight management for adults in 2012 and kids 12 and up in 2022. 

Pros: It’s a pill you take orally and it may also help with migraines, Strother says.  

Cons: Phentermine is a controlled substance which means the government tightly regulates its use because of its potential for abuse and addiction. It’s not safe for people with irregular heartbeat, structural heart disease and hyperthyroidism to take. And if stopped suddenly, phentermine can cause seizures.  

Also noteworthy: the phentermine/topiramate pill increases the risk of birth defects and shouldn’t be taken if you are pregnant or breastfeeding. 

Side effects: racing heart, increased blood pressure, increased risk of kidney stones, tingling in hands and feet, insomnia, brain fog, constipation and nervousness.  

Bupropion/naltrexone (brand name: Contrave) 

Another combo drug, this time with bupropion, an antidepressant, and naltrexone, which is used to treat alcohol and opioid addiction. As such, the medication will reduce the reward response in your brain to alcohol (along with other food), making them less appealing, Montour says. 

The combination was FDA approved in 2014 to decrease appetite and reduce cravings.  

Pros: This is another pill taken orally. 

Cons: You can’t take it with opioids, and it also isn’t safe to take if you have a history of seizures, bulimia or anorexia. 

Side effects: nausea, headaches, increased blood pressure and constipation.  

Liraglutide (Saxenda) 

Approved in 2014 for adults and 2020 for children 12 and up, liraglutide mimics the GLP-1 hormone in your body that helps regulate and suppress appetite by connecting your gut and brain so that you feel satisfied after eating. It works by increasing your body’s insulin production so that you are able to better regulate your sugar levels and thus is also used to treat type 2 diabetes.  

Pros: It’s highly effective. 

Cons: It requires daily injections, is pricey and may promote thyroid cancer, Strother says. Plus, the GLP-1 mimicking drug requires life-long use to avoid regaining the lost weight. It’s also unsafe for folks with a history of pancreatitis or multiple endocrine neoplasia (MEN) syndrome type 2.

Side effects: nausea, vomiting, gallstones, constipation and diarrhea.  

Semaglutide (brand name: Wegovy)

AKA, the weight loss drug all the celebrities are talking about. 

Wegovy was approved in 2021 and, like liraglutide, works by mimicking the GLP-1 hormone. The drug suppresses appetite, decreases glucose (sugar) absorption and slows down gut emptying, which means you feel fuller for longer. Semaglutide is also used to treat type 2 diabetes under the brand names Ozempic (an injection) and Rybelsus (a pill). 

Pros: It’s highly effective — trials of Wegovy showed that patients lost on average 15% body weight. (There is some weight regain if you stop the medication. Two years after stopping medications, studies found patients regained 10% of the lost weight and kept off 5%.) 

Cons: It requires a weekly injection and there have been shortages, so up until recently it’s been difficult to get the medication. Another reason it’s hard to get ahold of? The medication is pricey (as in, over a thousand dollars a month if not covered by insurance). 

Side effects: nausea, vomiting, constipation, diarrhea and fatigue. 

Setmelanotide (Imcivree) 

This medication is only approved for people 6 and older who have obesity from three rare genetic conditions: pro-opiomelanocortin deficiency, proprotein subtilisin-kexin type 1 deficiency or leptin receptor deficiency. 

“In patients with these genetic conditions, it helps control appetite since these people are constantly hungry due to a genetic disturbance of the hormones that control appetite,” Montour says.   

Pros: It’s a useful weight loss medication if you have a rare inherited condition. 

Cons: It requires a daily injection and is not an option if you do not have one of the above rare inherited conditions. 

Side effects: nausea, diarrhea, patches of darker skin, depression and unwanted erections. 

The bottom line 

New weight loss medications offer exciting advances in how we can treat obesity, but they aren’t magic. 

“Treatment of obesity, like any chronic disease, requires anti-obesity medication in conjunction with lifestyle modification,” Montour says. 

For many low-income patients, the medications’ prices and the fact that they are often not covered by insurance puts them out of reach. 

Plus, if you want to keep the weight off, most people will need to take the medications for the rest of their lives.  

“Weight loss requires a lifelong treatment plan. These are medications like blood pressure medication that will need to be continued. The body does not reset at a lower weight once weight is lost. Maintenance takes as much if not more to remain at a healthy weight,” Strother says. 

But the advances in these medications offer better weight management tools for people with chronic obesity. The new drugs are a safer and more effective way for the disease to be treated with medication, and that’s pretty exciting.