Wegovy (semaglutide) is a brand-name subcutaneous auto-injector pen prescribed to help with weight loss and long-term weight management in certain people. It’s a type of drug called a GLP-1 receptor agonist.

Wegovy is available as a liquid solution inside a prefilled, single-dose injection pen. Wegovy belongs to a drug class called glucagon-like peptide-1 (GLP-1) receptor agonists. The medication is not available in a generic version.

Read on for more information about Wegovy. You can also refer to this article for a comprehensive look at Wegovy.

The use of Wegovy for weight loss (its only approved use) may cause side effects that are mild or serious. The lists below include some of the main side effects that have been reported with Wegovy. For information about other potential side effects of the drug, talk with your doctor or pharmacist. You can also see our side effect article about Wegovy or refer to Wegovy’s prescribing information.

Note: After the Food and Drug Administration (FDA) approves a medication, it tracks and reviews side effects of the drug. If you develop a side effect while taking Wegovy and would like to inform the FDA, visit MedWatch.

Mild side effects

Like other medications, Wegovy can cause mild side effects. When the drug is used to aid weight loss, mild side effects may include:

These side effects of Wegovy may be temporary, lasting a few days to weeks. But if they last longer than this, or if they bother you or become severe, it’s important to talk with your doctor or pharmacist.

Serious side effects

Serious side effects can also occur with Wegovy. But in clinical studies, these weren’t common. Serious side effects reported with Wegovy include:

Call your doctor right away if you develop serious side effects while using Wegovy. If the side effects seem life threatening or you think you’re having a medical emergency, call 911 or your local emergency number immediately.

* Wegovy has a boxed warning for this side effect. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). To learn more, see the “Before using Wegovy” section below.
† An allergic reaction is possible after using Wegovy. However, this side effect wasn’t reported in clinical trials.

Find the answers to some frequently asked questions about Wegovy.

Is Wegovy the strongest weight loss drug? How does it compare with other drugs used for weight loss?

Wegovy is used to help with weight loss and long-term weight management. Other drugs prescribed for this use include:

  • liraglutide (Saxenda)
  • phentermine/topiramate (Qsymia)
  • naltrexone/bupropion (Contrave)
  • orlistat (Xenical, Alli)

Wegovy and Saxenda are in the same class of drugs (glucagon-like peptide-1 (GLP-1) receptor agonists). These drugs act similarly to a hormone in your body that regulates your appetite. Both drugs are given as a subcutaneous injection. Saxenda is used daily, whereas Wegovy is used weekly. These drugs have similar side effects. The most common include digestive problems such as nausea, indigestion, and flatulence (gas).

Qysmia and Contrave both act on various chemical messengers in your brain. They work in different ways to suppress your appetite and reduce food cravings. Both are taken daily by mouth. Common side effects of both these drugs include insomnia (trouble sleeping), dizziness, and dry mouth.

Xenical and Alli reduce the amount of fat your body absorbs from meals. These drugs are taken with meals containing fat, up to three times per day. Common side effects include frequent, sometimes uncontrollable bowel movements, oily stools, and gas with oily discharge.

All these drugs are effective for weight loss and long-term weight management. However, Wegovy appears to be the most effective. Recent guidelines recommend that doctors consider prescribing Wegovy before other medications for long-term weight management.

In clinical trials, Wegovy was slightly less effective in people with type 2 diabetes. And it may not be suitable for everyone.

To learn more about how Wegovy compares with other weight management drugs, talk with your doctor. They can help you determine the best treatment option for you.

How fast do you lose weight on Wegovy?

Wegovy starts working as soon as you begin taking it. Your dosage is increased slowly, so it may take a few weeks before you start losing weight. In clinical trials, people who took Wegovy steadily lost weight over a 68-week period.

In these trials, most people who took Wegovy lost at least 5% of their body weight over 68 weeks. And about half of the people who took Wegovy lost at least 15% of their body weight over this time.

Not everyone taking Wegovy will have the same experience with this drug. To learn more about what you can expect while taking Wegovy, talk with your doctor.

Do I have to take Wegovy long term?

Yes, Wegovy is meant to be a long-term treatment to help you manage your weight. You’ll take it as part of a long-term treatment plan that includes following a low calorie diet and regular exercise.

If you have questions about using Wegovy long term, talk with your doctor.

The cost of Wegovy is based on several factors. These can include your prescribed treatment regimen, your insurance plan, the pharmacy you use, and your location.

Wegovy is a brand-name drug. It’s not currently available as a generic. Brand-name drugs usually cost more than generics.

How to buy Wegovy

If you think Wegovy could be a weight management option for you, talk with your doctor. They can help determine whether Wegovy might be right for you and provide a prescription.

Another easy way to purchase Wegovy is by using a telemedicine provider such as Calibrate or Ro Body. Through these services, a licensed telehealth professional will give you a health evaluation. If the evaluation shows that Wegovy could be helpful for you, the telehealth professional will provide an electronic prescription. You can then use this prescription to order the medication through the service’s site. After you start taking the medication, the service will provide coaching and other support to help you manage your weight.

If you get a Wegovy prescription through Calibrate or Ro Body, we encourage you to tell your doctor. It’s important that your doctor know about all medications you take.

Wegovy is prescribed to help with weight loss and long-term weight management in the following people:

Wegovy is meant to be used alongside a low calorie diet and increased physical exercise. Your doctor or nutritionist can help you create a diet and exercise plan that works for you.

It’s not known whether it’s safe or effective to use Wegovy with other weight loss drugs. It should not be used with other glucagon-like peptide-1 (GLP-1) receptor agonists, such as liraglutide (Saxenda).

Wegovy and children

Wegovy is prescribed to help with weight loss and long-term weight management in certain children.

Specifically, it’s prescribed for children ages 12 years and older with a BMI in the 95th percentile or higher for their age and sex (obesity).

Wegovy is used to help with weight loss and long-term weight management.

The way Wegovy works

Wegovy is a type of drug called a glucagon-like peptide-1 (GLP-1) receptor agonist. It works by acting similarly to the action of a natural hormone in your body called GLP-1.

GLP-1 helps regulate your appetite and blood sugar levels. It produces the following effects:

  • slowed movement of food from your stomach to your intestine, making you feel fuller after eating
  • reduced appetite

Wegovy acts on the same sites in the brain as GLP-1. It produces the same effects as this hormone, which helps you consume fewer calories. Over time, this helps you lose weight and keep it off.

Clinical trials found Wegovy to be effective in helping long-term weight loss. Most people who took Wegovy in these trials lost at least 5% of their body weight over 68 weeks. And about half lost at least 15% of their body weight over this time.

In these trials, people who took Wegovy also had a reduced waist circumference and lowered blood pressure.

Note that in these trials, Wegovy was slightly less effective in people with type 2 diabetes.

To learn more about how Wegovy performed in clinical studies, see the drug’s prescribing information.

If lifestyle changes haven’t helped with weight management, several guidelines recommend using medications such as Wegovy to help with weight loss. The American Gastroenterological Association (AGA) recommends doctors consider prescribing semaglutide, in addition to lifestyle modifications, before other medications for the long-term management of obesity. Semaglutide is the active drug in Wegovy.

Wegovy comes as a liquid solution inside prefilled, single-dose injection pens. The pens are available in several different strengths.

Dosage

Your doctor will typically start you on a low dosage of Wegovy. This allows your body to get used to the medication and helps reduce the risk of digestive side effects. Your doctor will typically increase your dosage over time, as described in the table below. Doses are measured in milligrams (mg).

WeekUsual dosage for adults and children ages 12 years and older
1 to 40.25 mg once per week
5 to 80.5 mg once per week
9 to 121 mg once per week
13 to 161.7 mg once per week
17 and onward2.4 mg once per week

How to use

Wegovy is given as a subcutaneous injection in your abdomen, thigh, or upper arm.

Your doctor or another healthcare professional will teach you how to use a Wegovy pen to inject the medication yourself. You can also find instructions for using Wegovy on the manufacturer’s website.

How often to use

You should inject Wegovy once per week, on the same day each week. You can inject your dose at any time on that day.

Before you use Wegovy, there’s some important information to keep in mind. The drug may not be a safe option if you have certain medical conditions or other factors that affect your health. Some of these are mentioned below.

Boxed warning: Risk of thyroid cancer

Wegovy has a boxed warning for the risk of thyroid cancer. This is a serious warning from the Food and Drug Administration (FDA).

In animal studies, semaglutide (the active drug in Wegovy) caused thyroid tumors in rodents. However, animal studies don’t always predict what will happen in humans. It’s not known if Wegovy increases the risk of thyroid tumors in humans.

Due to this possible risk, your doctor will likely not prescribe Wegovy if:

  • you or someone in your family have ever had a type of thyroid cancer called medullary cell carcinoma
  • you have a rare condition that causes various types of tumors, called multiple endocrine neoplasia syndrome type 2 (MEN 2)

While taking Wegovy, you should contact your doctor if you develop symptoms of thyroid cancer. These may include persistent hoarseness, trouble swallowing, talking, or breathing, or a lump in your neck.

Other warnings

In addition to boxed warnings, Wegovy has other warnings.

If any of the following medical conditions or other health factors are relevant to you, talk with your doctor before using Wegovy:

Now that you’ve learned about Wegovy for weight loss, you may still have some questions. Talk with your doctor or pharmacist to find out whether Wegovy might be right for you.

Here are some other helpful references:

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.