Weight Loss Medications: Are They Effective?

There’s a reason why healthcare professionals may recommend weight loss prescription drugs, and it’s not just about achieving a certain look. It’s because on average, those who take medications as part of a weight management plan lose up to 12 percent more of their starting body weight than people who don’t.

There are plenty of FDA-approved weight loss drugs these days. But do they actually work or is it all hype? And which one is the best? Below, we’ll take a look at the best weight loss medications and how effective they really are.

Medications FDA-approved for weight loss are primarily intended for people with obesity or overweight plus an obesity-related condition. 

Whether you have obesity is generally determined by your body mass index (BMI), which uses your height and weight to see where you fall on the spectrum of what’s healthy. A BMI of 25 to 30 is considered overweight, and a BMI over 30 signifies obesity.

You’ve probably heard of some medications people use to manage their weight, like Wegovy® (semaglutide). But there are several different weight loss medications available. 

Semaglutide (Ozempic, Wegovy, Rybelsus)

You’re probably familiar with one of semaglutide’s brand names: Ozempic. Other brand names for this drug include Wegovy and Rybelsus®.

Ozempic and Rybelsus are FDA-approved to treat type 2 diabetes, but they’re sometimes prescribed off-label to help with weight loss. (Off-label is when a provider prescribes a drug for a purpose other than what it was FDA-approved to treat). 

Wegovy is a prescription medication approved for weight loss in people with obesity or people who are overweight with an obesity-related condition, like high blood pressure.

Ozempic and Wegovy are in a class of medication called GLP-1 receptor agonists. These drugs mimic a naturally occurring hormone called glucagon-like peptide-1, which affects areas of the brain responsible for appetite regulation.

Ozempic was approved by the FDA in 2017, while Wegovy was granted approval to pharmaceutical company Novo Nordisk more recently, in 2021.

Metformin

Although only approved by the FDA to treat diabetes, metformin is often used off-label for weight loss, as well as gestational diabetes (a type of diabetes that develops during pregnancy) and polycystic ovary syndrome (PCOS).

It isn’t exactly clear how metformin helps people lose weight, but researchers think the drug works as an appetite suppressant. Similar to semaglutide, metformin may increase how much GLP-1 hormone your body makes. This can send a signal to your brain that you’re full, which means you eat fewer calories.

Naltrexone-bupropion (Contrave®)

If you’ve dealt with depression or looked into medication to quit smoking, bupropion may sound familiar to you.

For weight loss, it can be combined with the drug naltrexone, which is used to treat alcohol and drug dependence, to curb your hunger or make you feel fuller sooner. Together, these medications work on two areas of the brain, the hunger center and the reward system, to reduce appetite and help control cravings.

Along with a reduced calorie diet and exercise plan, naltrexone-bupropion can also help keep excess weight off.

Phentermine-topiramate (Qsymia®)

Phentermine-topiramate is actually two separate medications that are combined in Qsymia, but are offered separately in other applications. 

While phentermine is considered an anorectic and topiramate is an anticonvulsant, both help with appetite suppression.

Topiramate offers the added benefit of helping you feel fuller longer after you eat.

When used specifically with a healthy exercise regimen and a reduced calorie diet, these medications — either together or separately — have been shown to help people lose weight and keep it off.

Orlistat (Xenical®, Alli®)

Orlistat, which belongs to a class of medications known as lipase inhibitors, reduces the amount of fat your body absorbs from the food you eat.

Orlistat is used for weight loss in conjunction with exercise and a reduced-calorie diet, as well as after weight loss to help people keep from gaining back that weight.

While the brand name Xenical requires a prescription, another brand called Alli is available in a lower dosage without one.

Liraglutide (Saxenda®)

Like Ozempic and Wegovy, liraglutide is an injected medication. It’s a GLP-1 receptor agonist that works to suppress appetite and regulate hunger hormones. Saxenda is FDA-approved for weight management in people with obesity. 

Liraglutide is also available under the brand name Victoza, which is FDA-approved to treat type 2 diabetes.

These weight loss drugs are all available with a prescription from a healthcare professional, but how effective are they really?

• One study on Wegovy found that when people without diabetes took 2.4 mg of semaglutide weekly they lost more weight — almost a 15 percent average decrease in weight — than people who took a placebo.

• Metformin has also demonstrated clinically significant weight loss. A 2020 meta-analysis of 21 trials testing metformin found the drug had a modest impact on lowering BMI, especially for those who are considered to have obesity.

• A smaller study on metformin also found that the average amount of weight lost in 154 patients was between 5.6 and 7 kgs (that’s roughly between 13 and 15 pounds).

It’s also worth mentioning cost here — if you can’t afford the drug you need to take, it’s effectiveness essentially drops to zero percent. That said, there’s some wide price disparity between weight loss drugs. 

For instance, injectables like Ozempic and Wegovy are generally more expensive than metformin — namely because metformin is a generic medication that’s been around for decades, and Ozempic and Wegovy are newer. 

Because everyone’s weight loss journey is different, weight loss medications may work slowly for some people and faster for others.

How long you need to take a weight loss prescription drug depends on various factors such as what side effects you experience, how much weight you need to lose, whether the drug helps keep the weight off and more.

Generally, weight loss occurs within the first few months of using a weight loss medication.

Sometimes your health care professional may recommend long-term use of the medication, while other people may be advised to stop the drug if they don’t lose a certain amount of weight after 12 weeks.

If you’re taking a weight loss medication, your healthcare provider will likely suggest that you also increase your physical activity and make healthy lifestyle changes like eating lots of protein and fiber and getting enough sleep. These medications are the most effective when combined with healthy habits.

Just like any medication, weight loss drugs also come with the possibility of side effects.

The most common side effects of many of these medications include:

• Stomach pain or constipation

• Diarrhea

• Nausea

• Vomiting

Some, like liraglutide and naltrexone-bupropion, may cause an increased heart rate or headaches.

Liraglutide and semaglutide may also increase the risk of pancreatitis (swelling of the pancreas). You may also have a higher risk of developing tumors or thyroid cancer when using liraglutide or semaglutide, although these serious side effects are very rare.

There’s a good chance you’ve heard of weight loss medications like Ozempic or even Wegovy, but there’s also a good chance that the headlines and celebrity-focused articles didn’t answer all your questions. Here’s what you need to know about whether they’re effective.

• There are several FDA-approved weight loss drugs, including Wegovy, orlistat, phentermine-topiramate, naltrexone-bupropion, and liraglutide. Metformin is another common medication used off-label for weight management.

• These drugs all work slightly differently, but many decrease your appetite and help you stick to a lower-calorie diet. Healthcare providers often recommend they be used alongside regular exercise and healthy habits to maximize sustained weight loss.

• However, there are side effects such as nausea, vomiting, diarrhea, and constipation. Often, these are mild and serious side effects are rare.

• Cost is also worth considering. Injectables like Ozempic and Wegovy can be costly, while a generic medication like metformin can be had for a fraction of the price — usually for under $100 a month.

There’s no one “best weight loss medication” — there’s only what’s best for your particular needs. If you’re curious about medication for weight loss, you can talk to your healthcare provider for medical advice and to explore your options. 

If you’re interested in weight loss medications, Hers can help. Consider taking our free online assessment to see if you qualify.