Side Effects of Wegovy for Teens

Emma Yasinski
Emma Yasinski Staff Writer
Last updated:

Wegovy (semaglutide), a popular diabetes drug, has gotten a lot more popular over the last 18 months. In June 2021, it was approved for a new indication—weight loss for patients with obesity, even if they didn’t have diabetes. While it’s only indicated for those with obesity, celebrities with seemingly healthy weights have claimed to be giving themselves the at-home injections in hopes of fitting into particularly form-fitting outfits for special events.

If you Google “wegovy” even once, you’ll likely start seeing ads on social media for telehealth companies that help manage weight, and of course, have doctors ready to prescribe a variety of drugs, including Wegovy.

Last summer, enthusiasm was high. MedShadow Foundation founder, Su Robotti, wrote an article about the drug in July of 2021, and patients quickly filled the comments section with stories of both dramatic weight loss and debilitating side effects.

Now, there’s a shortage. Try to read about the drug on its official website, Wegovy.com and you’ll be met with a popup that Wegovy is not currently available, but that manufacturing should ramp up to meet demand soon.

In November, researchers published another trial, testing the drug in adolescents with obesity. If your teen has obesity, here’s what you need to know before talking to their healthcare provider about Wegovy or any other weight loss drug.

Challenges in Treating Obesity

For decades, we’ve been living in an obesity epidemic. 

Body mass index (BMI) is a problematic measure of the health of your weight, but it’s still used to identify those that have overweight or fall in the “obesity” category. The Centers for Disease Control and Prevention (CDC) offers a simple BMI calculator here. Everyone’s body is different, however, the CDC explains that for most people, a BMI below 18.5 is considered underweight. A BMI between 18.5 to and 25 is considered healthy. A BMI between 25.0 and 30 denotes someone who has overweight, and a BMI over 30 is to signify that someone has obesity. About 41% of adults fall into that last category, obesity, according to  the CDC (Centers for Disease Control and Prevention).

And it’s not just adults. Nearly 20% of kids age 2-19 have obesity in the U.S. Rates, according to the CDC, are highest among Hispanic children and non-Hispanic Black children, and families with lower incomes. The condition is linked to an increased risk of myriad illnesses from heart disease to cancer.

Unfortunately, it’s becoming more and more clear that, while increasing physical activity and making dietary changes can help shed some extra body weight, in many cases, they may not do enough.

“We have been trying hard as healthcare professionals, and our patients even harder, to tackle obesity by lifestyle modification, and that is extremely difficult,” says Daniel Weghuber, MD, a pediatrician at Paracelsus Medical University in Austria, who was the primary author on the latest trial of Wegovy in teens. “But what we really need is drugs that are used alongside lifestyle treatment that are really effective.”

Weghuber says that NovoNordisk, the company that manufactures Wegovy funded the study, and covers his travel and attendance at conferences that are relevant to the work, but he does not receive other payments or fees for speaking at those conferences from the company.

Melanie Jay MD, a pediatrician and obesity researcher at NYU Langone points out that while diet and exercise play a role in maintaining a healthy weight, “most of the reasons for having obesity are not within the patient’s control. It’s more heritable than height, actually. It’s the interactions of genes and environment.” She adds that there are hormone disruptors in the environment that play a role as well.

Drugs That Treat Obesity

Drugs that target GLP-1 (glucagon-like peptide-1) have been used to treat diabetes since 2005. As patients and doctors started to notice unintentional weight loss that accompanied use of the drugs, scientists started testing these types of drugs for that explicit purpose, rather than just for diabetes treatment.

Wegovy is the first semaglutide FDA approved for weight loss, but another injectible semaglutide, Ozempic, made by the same company (NovoNordisk), approved in 2017 to treat type 2 diabetes, has regularly mentioned the potential for patients to lose weight in its ads since 2018, stating that a study showed that adults lost up to 12 pounds on average while they took the drug for diabetes (with the caveat in small print, of course, that it is not a weight loss drug). Both drugs contain the same active ingredient, semaglutide, but Wegovy is available in higher doses than Ozempic.

There are five other drugs approved for weight loss, but experts say their impacts are modest compared to Wegovy. 

How Wegovy Works for Weight loss 

Wegovy is known as a GLP-1 receptor agonist. Essentially, it mimics a hormone that helps us feel full and tells our stomach to take its time emptying food.

“The main mechanism of action is in the brain,” says Weghuber. “Patients will tell us that now that they’re on the drug for the first time ever they’re in the position to adhere to lifestyle recommendations that they have understood all the time.”

When you’re taking a GLP-1 drug such as Wegovy, you’ll likely feel full after eating much smaller quantities of food than you’re used to consuming.

Side Effects of Wegovy

In both the adult and adolescent clinical trials, patients commonly reported the following side effects of Wegovy:

  • Nausea
  • Diarrhea
  • Vomiting
  • Heartburn
  • Rashes
  • Hives

GLP-1 drugs could raise your risk for certain types of thyroid cancer, and the manufacturer recommends that people with a family history of medullary thyroid cancer in particular avoid the drug.  

Some researchers are drawing attention to the fact that it may increase your risk for an intestinal obstruction. That’s when food is blocked from making it all the way through your digestive tract, and you may need surgery to correct it. However, more research is needed to understand the assocation.

Any weight loss regimen, including GLP-1 drugs, can cause you to lose muscle mass, so some scientists recommend making sure you incorporate weight training into your exercise routine.

Users have taken to TikTok to describe the nausea they’ve had with Wegovy and how they’ve handled it.

TikToker Izzi1434 describes her first week, saying she’s had “very bad heartburn” and fatigue. She also describes intense fullness after eating, including two times severe enough that she threw up. Eating several smaller meals and snacks throughout the day has helped her manage the nausea.


Another TikToker, Bossfidence, says she’s often extremely nauseous on the day she takes the injections. She also has migraine-like headaches and serious constipation. She has to remind herself to drink water to maintain hydration on Wegovy.


Other TikTokers have posted about lesser-known side effects such as rage and feeling cold.

Despite the side effects, most people in the clinical trial continued taking the drug. Jay suggests that it’s likely because clinical trials are designed to provide the patients with support and education about how to manage nausea and other effects that people in the real world may not get. 

“We don’t have data on it,” she says, “but I think a lot more people in the real world go off of it.”  

The TikTokers often mentioned eating smaller meals more frequently in order to avoid nausea. Jay explains that one of the ways that the drug works is by keeping food in your stomach longer than it would typically stay there. In addition to eating smaller portions, she says high-fat foods can worsen side effects because they naturally stay in the stomach longer even without the drug. 

The Teen Wegovy Study

Just a little more than a year after the FDA approved Wegovy for adults, researchers published a trial testing the drug in adolescents.

The study included 131 teens who were given Wegovy, and 62 who were given a weekly placebo injection for 68 weeks (about a year and four months.) Both groups met with dieticians as part of a lifestyle intervention. Those teens who were given semaglutide lost 16% of their BMI, compared to only 0.6% in the placebo group. Adults lost only 6-12.4% of their body weight in clinical trials.

A pediatrician called the results of the trial “mind-blowing”. It’s not clear why, but the drug seemed to cause even more weight loss in the teens than the adults. Weghuber says there’s some speculation that it could be because the “reward systems” that the drug acts on are more sensitive in the adolescent brains than those of adults.

“There were no new safety signals. The side effects in teens were very, very comparable to those that we have seen in adults,” says Weghuber, adding that the most common side effects were gastrointestinal distress and rashes or hives. He did point out that five adolescents taking Wegovy developed gallstones, a known risk of rapid weight loss by any means.

Weghuber says that the gastrointestinal side effects were “expected,” adding that “they were more frequent in the first weeks, which is well known, and they fade away after six to eight weeks.”

He also emphasized that along with improvements in body weight, blood sugar, and other measures of health, the teens who took Wegovy reported better quality of life. 

“A 14-year-old does not ask ‘how are my cardiovascular risk factors?’ So it’s good to see quality of life is improving,” he says.

Who Can Get a Prescription for Wegovy* 

In June 2021, the FDA approved Wegovy for weight loss in adults who have a BMI higher than 30, or who have a BMI between 27 and 30 alongside a weight-related condition such as diabetes or high cholesterol.

However, once a drug is approved, it can be prescribed “off-label” at the prescriber’s discretion. That means that a provider may suggest it for someone who has a BMI of 26 alongside a weight-related condition or for an adolescent. This is a frequent practice, especially in pediatrics, explains Jay, because fewer drugs are tested in children than in adults. However, she emphasizes that many people have had trouble getting insurance to cover the drug, and many doctors are unlikely to prescribe it to younger patients because they don’t perceive obesity as an emergency.

Since the drug was approved for weight loss, there has been a Wegovy shortage in the U.S. One of the TikTokers above mentioned she’d need to switch drugs within two weeks because a refill of her Wegovy was no longer available. Production is expected to ramp up in early 2023.

But Jay still expects it’ll be difficult to come by for many people, shortage or not. 

“It’s very, very expensive and not covered by a lot of insurance,” says Jay.

*as of December 2022

What to Expect with Wegovy

Wegovy is a weekly injection that you can give yourself at home. You can place it in your arm, stomach or thigh. TikToker bigdawg_lifestyle shows how in this video. (A reminder from MedShadow: The creator in this video discusses using a supplement to reduce side effects of Wegovy. Before you take that advice, be sure to research the companies manufacturing any supplements you purchase and discuss them with your healthcare provider before using them.)

When you start taking Wegovy, your healthcare provider may recommend starting with a low dose and raising it over several weeks. Most people, (90% of the patients in the adolescent trial) will end up taking the highest dose, 2.4mg.

As you take the drug, you will start to feel full very quickly after eating and may not have much of an appetite or even the desire to drink water. Dehydration can be a serious complication of diarrhea and vomiting, so staying hydrated is very important. In the first several weeks, many patients experience nausea, vomiting, constipation, and other gastrointestinal side effects. For some people it lessened after the first six weeks or so.

There is risk inherent with any new drug, because our knowledge of potential adverse events associated with the drug is limited by the length of the trials, which in this case, lasted 1-2 years. On the positive side, lower doses of semaglutide, the active ingredient in Wegovy, have been used to treat diabetes for several years now, though UpToDate, a site that aggregates research about treatments to support decision-making by physicians, notes that there have been very few trials lasting more than four years, so the long term safety of these drugs is not yet established. 

Most clinical trials for Wegovy for weight loss lasted a little over a year. A two-year study in adults showed that weight loss tended to plateau at about 68 weeks, but that those who continued to take the drug, maintained their weights. Unfortunately, that does not mean that most people can take it for a year and stop taking it. “The effect does fade away as soon as you stop taking the drug,” says Weghuber. Typically, adults who stopped taking the drug started to gain weight again. We don’t yet know if this is also true for adolescents, but experts say they expect it will be.

“Obesity is a chronic disease and should be treated that way,” says Jay. You should be prepared for the possibility that you’ll need to take the drug long-term. 

Before Your Teen Tries Wegovy

Jay was generally optimistic about the potential for Wegovy and similar drugs to help both adults and adolescents lose weight, but she emphasized that “the first step is not medications.” People looking to lose weight should start with lifestyle modifications such as increased physical activity and dietary interventions.

MedShadow offers several resources for those looking for guidance:

Mediterranean Diet guide

Strength Training for Beginners

Outdoor Workouts When You Don’t Feel Like Running

If you’re not seeing weight loss trying these interventions alone, then you might consider enrolling your teen in a comprehensive behavioral program. The National Institutes of Health (NIH) offers tips for finding a program that’s right for you or your teen. Make sure the program is designed to lead to slow and steady weight loss (no more than 1-2 lbs per week), and isn’t using extremely restrictive diets to promise quick, short-term solutions. The program should help establish a lifestyle change over the course of six months or more, that you or your child can stick with for life.

Finally, you might consider combining an intensive program with drugs like Wegovy.   

DISCLAIMER: MedShadow provides information and resources related to medications, their effects, and potential side effects. However, it is important to note that we are not a substitute for professional medical advice, diagnosis, or treatment. The content on our site is intended for educational and informational purposes only. Individuals dealing with medical conditions or symptoms should seek guidance from a licensed healthcare professional, such as a physician or pharmacist, who can provide personalized medical advice tailored to their specific circumstances.

While we strive to ensure the accuracy and reliability of the information presented on MedShadow, we cannot guarantee its completeness or suitability for any particular individual's medical needs. Therefore, we strongly encourage users to consult with qualified healthcare professionals regarding any health-related concerns or decisions. By accessing and using MedShadow, you acknowledge and agree that the information provided on the site is not a substitute for professional medical advice and that you should always consult with a qualified healthcare provider for any medical concerns.

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