Wegovy is a popular once-weekly injectable drug that has been approved for people who are overweight or obese. 

If you’ve been prescribed Wegovy, you may wonder how Wegovy helps people to lose weight and what other effects the medication has on the body. 

This article will tell you what you need to know about Wegovy and weight loss.

Image of scale and tape measure

What is Wegovy?

The Food and Drug Administration (FDA) approved Wegovy in June 2021 for people who are obese or who are overweight and have at least one weight-related condition.

Wegovy’s is the brand name for Novo Nordisk’s version of the drug semaglutide—but Wegovy has the same active ingredient as other drugs like Ozempic.

Wegovy, and other semaglutide drugs, are glucagon-like peptide-1 (GLP-1) receptor agonists. 

GLP-1 medications are essentially synthetic versions of a naturally occurring hormone that works in the body in a number of ways at once.

This hormone helps people reduce the amount of food they eat by decreasing their appetite and by slowing down the digestive process. 

By delaying the emptying of food from your stomach into your small intestine, it helps you to keep feeling full for longer after each meal.

Wegovy also stimulates the pancreas to release insulin and also slows down your liver’s production of glucagon. 

These changes tend to decrease insulin resistance and lower overall blood sugar levels.

Overall, the changes help people who struggle with their weight or who have blood sugar levels that are occasionally too high. 

Wegovy comes in five different sizes of auto-injector pens with pre-measured doses ranging from 0.25 milligrams (mg) up to 2.4 mg. 

People new to the medicine are prescribed a low dose which their doctor gradually increases over time.

It usually takes 17 weeks or more to build from the starting dose to the maximum “maintenance” dose.

Injections of Wegovy are taken one time per week on a consistent day and are not dependent on meal schedules. 

Will my doctor prescribe Wegovy for weight loss?

The FDA approved Wegovy specifically to help people lose weight. 

Its approval is for people to use the drug if they are either obese or if they are overweight with at least one weight-related condition.

Generally speaking, a person needs to have a body mass index (BMI) of 30 or more in order to be prescribed Wegovy. 

If a person has a weight-related condition like hypertension, sleep apnea, or certain heart conditions, then a BMI of 27 or higher will often be eligible too.

Some doctors do prescribe the medication to people who are overweight but do not have a weight-related condition. 

However, this is considered to be an off-label purpose—meaning a prescription for someone who wouldn’t normally be able to get the drug or for a purpose beyond the scope of the FDA’s approval.

Anecdotally, most doctors will not prescribe Wegovy unless you’ve struggled to lose weight through dieting and exercise alone. 

It’s also important to note that Wegovy is intended to be prescribed in conjunction with recommendations around eating a reduced-calorie diet and instructions for increasing physical activity.

How much weight do people lose on Wegovy?

While everyone’s experience is different, Wegovy has been demonstrated to help people to lose a considerable amount of weight. 

Wegovy suppresses the appetite and slows down the digestive process so people taking it tend to eat less without feeling deprived. 

Decreasing the amount of glucose released by the liver also helps to improve metabolic health. 

Taken together, these changes help people to lose weight. 

Clinical trials demonstrated 85% of people taking the drug lost 5% or more of their body weight compared to those who weren’t taking it.

Compared to other drugs that were available historically, this is a high level of effectiveness. 

In the clinical trial known as STEP 4, about 40% of the participants taking the active ingredient in Wegovy lost 20% or more of their body weight while taking the medication. 

The most common amount of weight to lose was 10.6% of their pre-trial weight.

How much weight you would expect to lose also depends in part on how long you’ve been taking the medication. 

How quickly do you see weight loss with Wegovy?

Weight loss takes time—and most of the studies of Wegovy are relatively long-term. 

The three primary clinical trials the FDA relied upon when reviewing Wegovy for approval tested weight loss through 68 weeks.

For most clinical trial participants, weight loss plateaued around 52 weeks (one year) on the medication. 

While a year was about average to see maximum weight loss, some people reached this point earlier, and some continued losing weight through the 68-week trial endpoint.

However, some amount of weight loss can happen quickly.

A clinical trial showed that most people lost 6% of their starting body weight within 12 weeks of starting Wegovy when following diet and exercise recommendations. 

By one year in this trial, the average weight loss was nearly 16% of starting body weight.

It’s always a good idea to plan for the long game when trying to lose weight. 

However, Wegovy has shown good outcomes across short, medium, and long terms. 

Talk with your doctor before starting the medication. They can tell you what to expect and how long it might be before you should expect results.

How much Wegovy do you need to take for weight loss?

Clinical trials of people who are overweight or obese and begin taking semaglutide—the active ingredient in Wegovy—experienced considerable weight loss at higher doses of the medication. 

People who took the maximum 2.4 mg dose per week saw their average body weight drop by nearly 15%, compared to just 2.4% with a placebo. 

This was despite both groups being given the same guidance to eat a restricted diet and get exercise.

For this reason, the recommended target dose of Wegovy is 2.4 mg per week. It usually takes 17 weeks or so to work up to this dose. 

Other clinical trials of semaglutide show that even lower doses can lead to weight loss and have other benefits. 

However, the approved treatment modality of Wegovy is one of “building” towards the maximum weekly dose of 2.4 mg and then maintaining it over time.

The FDA advises medical providers to discontinue treatment with Wegovy if a patient cannot tolerate the full 2.4 mg dose after building it over time. 

Some people will experience nausea or digestive issues at the maximum dose. 

Doctors may decrease their dose temporarily before attempting to go back up to the 2.4 mg dose, which has the strongest evidence base for significant weight loss.

Will I gain the weight back if I stop taking Wegovy?

Some weight loss during Wegovy does appear to be long-lasting, even if you stop taking the medication. 

However, most people do regain a significant amount of weight after stopping Wegovy. 

Research has shown that one year after stopping treatment with the drug, most people will regain about two-thirds of the weight that they lost while taking it.

So while Wegovy can be an important weight loss tool, the drug needs to be paired with dietary changes and increased exercise to be maximally effective. 

If you stop taking the medication, you should expect to see some weight gain.

Your doctor, nutritionist, and other medical providers can give you more information about how starting or stopping Wegovy could impact your weight and overall health. 

What is the largest dose of Wegovy for weight loss?

The largest weekly dose of Wegovy comes in the 2.4-milligram dose pen. This pen usually has a dark gray label.

While a doctor might prescribe more “off-label” in some limited circumstances, the largest dose that is currently available is 2.4 milligrams per week. 

Above this weekly dose, many people experience more noticeable side effects.

All the clinical trials that led to Wegovy’s approval pointed to this 2.4 mg per week dose as being the most effective for weight loss. 

At this weekly dose, the average person loses more than 10% of their starting weight.

What is the best time to take Wegovy?

There is no clinically demonstrated best time of day to take Wegovy. 

Rather, the most important thing is to select a day of the week and consistently take it on that same day each week.

If you decide to take Wegovy on a Monday, you can take it any time of day—but you should plan to take your weekly dose of Wegovy each Monday for as long as you use the medication.

Many people decide to write the day of the week they take the drug on a calendar or on the box that their Wegovy pen comes in. 

Phone reminders are also helpful to make sure you don’t miss a dose. 

What are the side effects of Wegovy?

Many people who take Wegovy will experience some side effects. 

The most common side effects are:

  • Nausea
  • Vomiting 
  • Diarrhea 
  • Stomach pain
  • Constipation 
  • Heartburn
  • Gas or bloat
  • Tiredness 

Some people will also experience hypoglycemia (low blood sugar), especially if they take insulin at the same time. 

It’s important to be aware of the symptoms of low blood sugar and know how to act to correct it.

Low blood sugar can be dangerous if untreated, so be on the lookout for:

  • Dizziness or light-headedness 
  • Confusion 
  • Sudden changes in your mood or perception 
  • Shakiness 
  • A fast heartbeat 
  • Any of the other symptoms of hypoglycemia

There are also rare—but more serious—side effects and complications that you should be aware of:

  • Thyroid tumors, including cancer  
  • Pancreatitis 
  • Changes in vision 
  • Kidney problems 
  • Mental changes or depression
  • Serious allergic reactions

Talk with your doctor about potential side effects. 

They can answer the questions you have about Wegovy and its potential risks and benefits.