We know obesity is a chronic disease, but it was previously considered a behavioral problem, and there was a lack of resources surrounding it. However, because it’s taken more seriously, many new drugs are emerging to help fight an epidemic projected to affect almost 64 percent of the U.S. population by 2025, according to a study published in 2018 in the journal PLOS One.
This is where Wegovy® and Saxenda® come in. Both drugs seem pretty similar—they belong to the drug class glucagon-like peptide 1 (GLP-1) receptor agonists; they are approved by the U.S. Food and Drug Administration (FDA) for weight loss; and they’re both injectable.
Both weight loss medications’ efficacy in weight management has caused them to trend and resulted in shortages. Their manufacturer Novo Nordisk has improved the supply issues for Saxenda; however, the FDA lists Wegovy as currently in shortage.
So, if they’re so similar, then are they interchangeable? Or is one better than the other? Let’s explore.
Although both weight loss meds are GLP-1 receptor agonists and work in similar ways, the compounds are different. First, Saxenda is the brand name for liraglutide, while Wegovy is semaglutide. Those generic names may sound familiar to you because they’re also the active ingredients in the FDA-approved type 2 diabetes medicationsVictoza® (liraglutide) and Ozempic® (semaglutide). Also, consider that Saxenda and Wegovy come in higher doses than their counterparts.
Liraglutide has a shorter half-life than semaglutide, meaning it doesn’t stay in the body as long, so it doesn’t work as long. The difference in timing is pretty vast—the half-life of liraglutide is 13 to 15 hours, while semaglutide’s half-life is 165 hours. Both mimic the naturally occurring GLP-1 hormone that stimulates insulin secretion after eating and regulates appetite to support weight loss.
Liraglutide and semaglutide also help with gastric or stomach emptying—slowing the digestion of food through your stomach, causing you to feel full longer.
Another key difference is that Wegovy is only FDA-approved to treat adults with a body mass index (BMI) of 30 or higher or a BMI of 27 or higher with a weight-related condition like high blood pressure or high cholesterol. However, Saxenda is FDA-approved to treat adults and, as of December 2020, children ages 12 to 17 with obesity who weigh at least 132 pounds
With the current research, semaglutide is more effective for weight loss in some people. The results of a placebo-controlled clinical trial published in 2022 in JAMA, the journal of the American Medical Association, found that after 68 weeks, 338 participants had an average body weight loss of about 16 percent with semaglutide and about 6 percent with liraglutide (in combination with lifestyle counseling for diet and physical activity). That’s a big difference. Greater weight loss was definitely achieved with semaglutide.
Additionally, results from a 68-week trial of semaglutide versus a placebo (with lifestyle intervention) reported in The New England Journal of Medicine (NEJM) found that of 1,961 participants experienced an average weight loss of almost 15 percent with semaglutide and about 2 percent with the placebo.
Compare this to the results of a double-blind 56-week clinical trial published in the NEJM in 2015 on liraglutide with 3,731 patients who didn’t have type 2 diabetes but had a body mass index (BMI) of 30 or greater or a BMI of 27 or greater with treated or untreated dyslipidemia (high cholesterol) or hypertension (high blood pressure). The study found that 33.1 percent of participants on liraglutide lost at least 10 percent of their body weight versus only 10.6 percent of participants in the placebo group (both received counseling on lifestyle modification).
Saxenda and Wegovy are injectable medications, but the dosing schedules differ. Here’s how:
Liraglutide doses come in prefilled injectable pens. You’ll receive a 30-day supply of Saxenda; the injections occur once daily. Liraglutide doses are upped every week accordingly, depending on tolerance. Here is the recommended dosing schedule:
Week one: 0.6 mg
Week two: 1.2 mg
Week three: 1.8 mg
Week four: 2.4 mg
Week five: 3.0 mg (full dose)
Semaglitude also comes in prefilled injectable pens. But you’ll inject yourself once weekly, and your prescription will come with a 28-day supply. Your health care provider will decide what dose is right for you and where to begin.
Here is Wegovy’s recommended dosing schedule:
Month one: 0.25 mg/week
Month two: 0.5 mg/week
Month three: 1 mg/week
Month four: 1.7 mg/week
Month five (and beyond): 2.4 mg/week (full dose)
In the clinical trial of semaglutide vs liraglutide, some participants quit because liraglutide’s side effects were too severe. In fact, about 27 percent of participants who were on liraglutide quit compared to about 13 percent of those on semaglutide.
While most side effects are similar, the liraglutide side effects may be more extreme. JAMA noted that the shorter half-life of liraglutide may be “causing a more abrupt, and thus noticeable, return in hunger.” This may have caused some people to stop the trial instead of pursuing it further.
With that said, here are the most common side effects for liraglutide and semaglutide:
The general recommendation is to not take any GLP-1 drugs in combination with one another. So, the answer is no. Tell your health care provider about any meds you’re currently taking, whether they’re supplements and vitamins or prescription drugs, to ensure you don’t have any negative interactions.
The fact is, that’s entirely up to what’s best for you individually. Both weight loss drugs have been FDA-approved for weight loss and can help people manage their weight. It depends on how you tolerate the side effects and how they work for you. The good news is, if one doesn’t work out, you can always try the other.
Additionally, some people prefer the ease of only remembering a once-weekly injection with Wegovy instead of the once-daily Saxenda. Still, if that’s not a problem for you, it comes down to what’s the most sustainable and maintainable in your weight loss journey. Your health care professional will discuss the best option to help you.
*GLP-1 Note: "Found is not currently prescribing GLP-1 medications for weight loss, but we are considering it as a part of our strategy to help members meet their weight-loss goals in the future. Stay tuned for updates on a potential GLP-1 rollout at Found. Until then, we can still help you meet your weight-loss goals with our current online weight-loss program."
Found offers a science-backed approach to weight care that's based on your unique biology, psychology, lifestyle, and prescription medication needs. The average Found member loses 10 percent of their body weight during their first 12 months on the program. In total, members have lost 800,000 pounds to date. To start your journey with Found, take our quiz.