Wegovy(Semaglutide): Weight Loss Injection FDA Approved with few side effects

Medically reviewed and updated for 2026
Dr. Richard Lipman MD
Board-Certified Internist and Endocrinologist

What is Wegovy and Why is it a Revolutionary Treatment for Obesity–Wegovy vs. Ozempic

Wegovy, a fast-acting weight-loss injection, is a breakthrough treatment for obesity. I have treated hundreds of patients with Wegovy and find it to be safe, offer  rapid weight loss with few side effects. It is an FDA-approved medication in the GLP-1 receptor antagonist class. It obtained FDA approval in June 2021 for the short-term and long-term treatment of obesity.  Surprisingly, it’s not a new drug at all, but simply an increased dosage of the diabetic drug Ozempic (chemical name semaglutide) that millions of people around the world have used for more than 9 years for diabetes. As an endocrinologist and diabetologist, I have treated hundreds of diabetics with Ozempic. 

Ozempic-treated diabetics experience significant weight loss despite the major difficulties diabetics have with obesity.  The Ozempic standard dose is 1 mg injection once a week, while the Wegovy dose is 2.0-2.4 mg injection once a week. Wegovy, a higher dose of semaglutide, produces even greater weight loss than Ozempic. Although Ozempic is available in oral form, greater weight loss is observed with once-weekly injections. The Wegovy Weight Loss Injection, administered once weekly at 2.4 mg, produces the most significant weight loss. I have treated over 150 overweight patients with Wegovy since its release and noted exceptional weight loss with few side effects.  In April 2026 the FDA approved a higher dose of 7,2 mg of Wegovy per week.

How Much Weight Loss Can You Expect from Wegovy and  Ozempic?

Wegovy helps patients lose an average of about 15-20% of their body weight, almost double the rates produced by other prescription treatments. Early studies showed that more than a third of overweight patients lost 20% or more of their body weight when taking Wegovy because people start at different weights. Maybe older with reduced metabolism, and the marked difference in weight loss between men and women, it’s best to evaluate weight loss as a percent of weight loss from the starting or baseline weight.

In a recent trial, 40% of participants lost 20% or more of their body weight over a year (an example might be  a 40 lb. weight loss in a 200 lb. individual).

The amount of weight loss depends on several variables

1. Dose of medications–the higher the dose, the greater the weight loss
2. Initial weight–weight loss is always related to starting weight. The more you weigh, the more you lose per week.
3. Duration of treatment–you do not develop a tolerance to these medications as you do with the typical
weight loss medication like phentermine. You continue to lose weight as long as you take the medication.
4. Age and gender. Men lose weight faster than women, and younger people more than older people.
5.  Individuals with extensive food noises before treatment can lose signficant weght losss.

Note in the graph above, after 10 weekly injections,  the average participant who took Wegovy lost 16% of their body weight, and those receiving a placebo lost only 4% of body weight on the same diet and exercise plan. Note the weight regain after 52 weeks with a placebo.

Who Should Take Wegovy(Semaglutide)

Wegovy is indicated for adults who are obese (body mass index ≥30) or overweight (body mass index ≥27). It can also be used with a BMI >27 in patients with type 2 diabetes, hypertension, and high cholesterol. The drug is used for short-term weight management but has been especially designed and tested for long-term weight loss and control. This is in conjunction with a reduced-calorie meal plan and increased physical activity. FDA approved Wegovy based on phase 3 data, which showed that Wegovy helped 33% of patients lose more than 20% of their body weight over a 68-week clinical trial period. This high-dose version of  Ozempic -semaglutide is a first of it’s kind obesity medication in that it is dosed on a once-weekly basis by injection.

How Does the Wegovy Weight Loss Injection  Produce Weight Loss if it’s only once a week?

Wegovy, like its lower-dose diabetes drug, Ozempic, acts on GLP-1 receptors in the brain, stomach, liver, pancreas, and muscle. The most critical effects occur in the brain, where Wegovy binds to GLP-1 receptors to reduce appetite, hunger, and cravings, especially for sweet and salty pleasure-producing foods.  In the stomach, it reduces gastric emptying time, thereby producing a sense of fullness. This results in reduced hunger and earlier satiety. Wegovy affects muscles by increasing sugar uptake and the pancreas by increasing insulin production and decreasing glucagon secretion (a hormone that causes hunger).  All of these effects result in less food intake and weight loss.

Here is how Wegovy – Ozempic produces such significant weight loss -note the interaction with many organs in the body, the final result being less food intake:

Wegovy Results in a Marked Decrease in Food Intake

 A recent study from Germany, where participants consumed as much food as they desired, found that the placebo participants ate 2676 calories a day while the Wegovy participants ate only 1736 calories, a reduction in energy intake of more than 33%! The major effects in this study were an average of 10% reduction in hunger, 15% increase in satiety, and 17%  increase in fullness. Note this finding is important in that there was no planned diet or exercise program. The weight reduction was due to a marked decrease in daily food intake of more than 900 calories.(Most diet plans strive for a reduction of about 500 calories a day or 1 lb. weight loss.) WEIGHT LOSS REPORTS show MORE THAN 20% OF INDIVIDUALS LOSE 20% OF THEIR EXCESS WEIGHT. WEIGHT LOSS IS ALMOST AS GOOD AS A GASTRIC BYPASS.

Animal studies have shown that Wegovy effects the brain by blocking GLP-1 receptors in the hypothalamus and hindbrain that are involved in appetite regulation, food intake, food preferences, reward and meal termination. This is in the lateral parabrachial nucleus. More recent studies have shown benefits on he brain and other internal organs such as the liver, blood vessels,and even addiction from these semaglutides.

How is Wegovy Taken?
Wegovy is supplied in a single dose pen injector.  It is self administered once a week on the same day of the week subcutaneously to the arm, abdomen or thigh. There are 5 doses ranging from 0.25 mg to 2.4 mg. Dosing starts at the lowest dose of 0.25 mg  weekly for 4 weeks. The dose is increased in 4 week intervals until the 2.4 mg dose is reached. This becomes the maintenance dose. It is taken as long as needed, recent studies have participants taking it for 63 weeks.

Wegovy vs. Ozempic:  Same Drug- but Higher Dose

Both drugs are the same chemical, but Wegovy is taken at higher doses after the initial titration. Max dose of ozempic is 1 mg and max dose of Wegovy is 2.4 mg. that’s the only difference. Same side effects, which are dose-related, as is the weight loss.

Using Ozempic Instead of Wegovy for Weight Loss–May Lower Cost

Lack of insurance coverage and high cost for Wegovy has prompted some overweight individuals to use Ozempic instead of Wegovy.  
Detailed instructions are included in another posting.

The most common side effects reported by more than 5 % of patients include nausea, vomiting, constipation, abdominal pain, headache, fatigue, dyspepsia and reflux. The side effects are due to the effects of Wegovy on the stomach including delaying gastric emptying for hours. This results in fullness for long periods of time and less hunger.

What are Warnings about Wegovy?
Ozempic and Wegovy are the same drug–just a higher dose.  Like Ozempic, the higher dose Wegovy is contraindicated in patients  with Medullary thyroid cancer or in patients with Multiple Endocrine Neoplasia Syndrome. There is increase in thyroid nodules and possible Thyroid C-cell tumors.  Acute pancreatitis has also been reported in this group of medications but is extremely rare.  Wegovy should not be taken with insulin. All of these side effects are extremely rare as evidenced by the widespread use and safety of Ozempic which is the same chemical as Wegovy.

How is Wegovy taken?  Wegovy is taken as a Single Injection Once a Week:
Four self injecting Wegovy pens are supplied in each monthly box.  The pens are all same dose and there is no dose adjustment like Ozempic.  The first month the once a week injection consists of 0.25 mg. There are 5 boxes for the 5 doses from 0.25 mg a week to the strongest of 2.4 mg a week. Each month the dosage is increased to 2.4 mg/week. The is the “maintenance dose.” Wegovy is a prescription drug requiring a personal evaluation by a licensed physician.

Costs of Wegovy Injections for Weight Loss

Wegovy is an expensive medication. The price has been changing recently. The cash price per month is $1600, it can be reduced with easily available coupons  such as supplied by Goodrx.com to about $1200. Some insurance companies pay for it depending upon body weight. Most require a BMI of 30 or more, or 27 or more if you have co-comorbidities like hypertension, arthritis or diabetes.  Novo offers savings cards with a month of medication for either $0 or $25 per month depending on insurance coverage.

Reviews and Ratings of Wegovy from the Literature

Here are some of he early ratings of Wegovy when it first was released in the summer of 2021. My patients have had excellent responses to the drug with 4-5 patients losing more than 100 lbs in 4-6 months. the average weight loss among the first 30 patients over 3 months was  3.5 lbs. per week. The most weight loss I have observed is 130 lbs in a patient who started at over 400 lbs.