How does Wegovy work for weight loss?

Approximately 70% of adults in the United States are considered overweight or obese. Obesity is a serious health issue associated with complications such as cardiovascular disease, stroke, diabetes, and death. It is also linked to an increased risk of certain types of cancer. Diet and exercise are the first steps in losing weight and getting healthy. If diet and exercise aren’t enough, your doctor may prescribe a medication such as Wegovy (semaglutide) to help with weight management. Keep reading to find out more about Wegovy and how it works to help you lose weight.

What is Wegovy (semaglutide)?

Wegovy is a glucagon-like peptide-1 or GLP-1 receptor agonist that is manufactured by Novo Nordisk. It is approved by the U.S. Food and Drug Administration (FDA) along with a reduced calorie diet and increased physical activity for chronic weight management in adults with a body mass index (BMI) of:

• 30 kg/m^2 or greater (obesity)
• 27 kg/m^2 or greater (overweight) with at least 1 weight-related condition such as high blood pressure, type 2 diabetes (T2DM), or high cholesterol

It is also used in pediatric patients 12 years of age and older with a BMI at the 95th percentile or greater for their age and sex, which is considered obese.

The active ingredient in Wegovy is semaglutide. Semaglutide is available in other versions used to manage blood glucose levels in patients with T2DM. It is marketed as a subcutaneous injection under the brand name Ozempic and as an oral tablet under the brand name Rybelsus. Ozempic and Rybelsus are not FDA-approved as weight loss drugs.

How does Wegovy work for weight loss?

Wegovy is a brand-name weight loss medication that belongs to the class of medications called glucagon-like peptide-1 (GLP-1) receptor agonists. It stimulates your pancreas to release insulin while preventing the release of glucagon. These 2 hormones work together to regulate your blood sugar levels. Insulin is released in response to food and helps your body absorb sugar to use for energy. Glucagon is released when your blood sugar is low signaling to your liver to break down and secrete stored sugars into your bloodstream.

So how does it work for weight loss? In addition to increasing the production of insulin, GLP-1 also targets areas of your brain that help regulate appetite after eating. Wegovy injections also slow down have fast the food you eat leaves your stomach, which makes you feel full (satiety) for longer. By helping you feel full and satisfied after a meal, it can lead to reduced cravings and food intake. Wegovy works best when it is used along with lifestyle changes including a healthy diet and regular exercise.

How effective is Wegovy for weight loss?

The safety and efficacy of Wegovy have been demonstrated in several clinical trials. It found that when used along with diet and exercise:

• 83% of adult patients using Wegovy lost 5% or more body weight, compared to 31% taking a placebo
• 66% of adult patients using Wegovy lost 10% or more body weight, compared to 12% taking a placebo
• 48% of adult patients using Wegovy lost 15% or more body weight, compared to 5% taking a placebo

How much weight can you lose with Wegovy?

In a clinical study of almost 2,000 adults with obesity or excess weight that lasted 68 weeks, those taking Wegovy lost more weight when compared to placebo. The average starting weight in each group was around 232 pounds. Adults taking Wegovy lost an average of 35 pounds or around 15% of their body weight. Those taking placebo lost an average of 6 pounds or around 2.5% of their body weight.

How fast do you lose weight with Wegovy? 

You may start to see a decrease in your appetite and some weight loss within the first 4 weeks of Wegovy treatment but its full effects can take several months or longer. In one clinical study, some people were switched to placebo after 20 weeks while others stayed on Wegovy. Between weeks 20 to 68, Wegovy patients continued to lose weight while those on placebo saw weight gain.

What are some side effects of Wegovy?

The most common side effects of Wegovy seen in clinical trials when compared to placebo include:

• Nausea
• Vomiting
• Constipation
• Diarrhea
• Abdominal pain
• Headache
• Fatigue
• Bloating
• Heartburn
• Acid reflux
• Gas
• Burping
• Common cold symptoms
• Increased heart rate

Wegovy can sometimes cause serious side effects such as:

• Serious, life-threatening allergic reactions (hives, swelling of the tongue or throat, and trouble breathing)
• Pancreatitis (inflammation of your pancreas)
• Acute gallbladder disease including gallstones
• Increased risk of thyroid cancer or thyroid tumors
• Hypoglycemia (low blood sugar levels), especially if used along with other diabetes drugs such as an insulin secretagogue or insulin
• Diabetic retinopathy complications
• Acute kidney injury and worsening of chronic renal failure
• Increased risk of suicidal thoughts and behaviors

Speak with your healthcare provider about the possible drug interactions with any other prescription drugs, over-the-counter products, vitamins, and supplements you are taking. These are not all of the possible side effects of Wegovy. You should always seek medical advice for any questions or concerns relating to your medical condition or treatment. You can report side effects to FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

How do you take Wegovy?

• Read the Prescribing Information, Instructions for Use, and Medication Guide that comes with Wegovy.
• Use this medication exactly as your doctor prescribes it to you. Do not change your dose or stop taking Wegovy without discussing it with them first.
• Your doctor should demonstrate how to use Wegovy before you give your first dose.
• Wegovy is injected under the skin of your abdomen, thigh, or upper arm. You should not inject this medication into a muscle or vein. Rotate your injection site with each Wegovy injection.
• Wegovy is injected once a week on the same day each week. You can inject this medication at any time of the day. You can change the day of the week you use Wegovy as long as the last dose was given at least 2 days before.

What should you tell your doctor before starting Wegovy?

Before beginning Wegovy treatment, tell your doctor about all your medical conditions, including:

• Kidney or pancreas problems
• Type 2 diabetes and a history of diabetic retinopathy
• Current or history of depression, suicidal thoughts, or mental health issues
• Personal or family history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia syndrome type 2 (MEN 2)
• Are pregnant, plan to become pregnant, or are breastfeeding 

Does Wegovy cause hair loss?

According to the manufacturer, hair loss was seen in 3% of obese or overweight adults taking Wegovy for chronic weight management. It was seen in 1% of adults taking placebo in the same study.

What foods can you eat while on Wegovy?

To get the best results from a weight loss program, medications such as Wegovy should be taken along with a healthy diet and regular exercise. This means avoiding foods processed foods that are high in sugar, cholesterol, trans fats, and saturated fats. Instead, you should make healthy food choices that can include:

• Lean meats that are high in protein such as turkey, chicken, tuna, lentils, and chickpeas
• Fresh fruits and vegetables
• Whole grains such as whole-wheat pasta, quinoa, and brown rice

How often can you take Wegovy?

Wegovy is given as a subcutaneous injection (under the skin) in your stomach, thigh, or upper arm once a week. It should be given on the same day of the week each week.