Key takeaways

  • It’s unlikely that you’ll see noticeable weight changes in the first week of Wegovy. But your doctor might observe improvements in your blood pressure or blood sugar levels.
  • You could experience side effects such as nausea, diarrhea, or constipation in the first week. You might experience some of these or other side effects in later weeks of treatment.
  • With Wegovy treatment, you may notice differences in how you feel about food (appetite, cravings, choices). These may help you lose weight. If you take Wegovy for MASH, you may have less fatigue, reduced pain, and improvement in skin color.

Wegovy (semaglutide) is approved by the Food and Drug Administration (FDA) for weight management in some people who are overweight or have obesity. It comes as a once-weekly injection or a daily pill.

Wegovy is also FDA-approved to reduce the risk of major heart or blood vessel problems in adults.

In 2025, Wegovy received accelerated approval to treat metabolic dysfunction-associated steatohepatitis (MASH) in some adults who have moderate to advanced liver fibrosis. (MASH was formerly known as nonalcoholic steatohepatitis [NASH].) Final approval for MASH may depend on further study.

Read on to learn what you might expect in your first week of treatment with Wegovy and beyond. You can also learn how long it generally takes to see noticeable weight loss.

Continue reading to learn what you might expect in your first week of treatment with Wegovy. Your results and side effects may depend on the condition Wegovy is treating. Other conditions you may have and other medications you take also could affect your results and side effects.

What first-week results can I expect with Wegovy?

You’re unlikely to see any noticeable changes in your weight during the first week of Wegovy treatment. It takes some time for the medication to take effect. Even so, your doctor may notice changes in some of your health markers. These might include blood pressure or blood sugar levels.

Most studies on the effectiveness of Wegovy for weight loss have looked at results over 12 weeks or longer. But some people may have noticeable weight loss in 4 weeks or even less.

Scene viewed through an open door of two dark-skinned women with short, dark hair standing face-to-face in an office that has a small desk, some chairs, and a side table: the woman on the left in a lab coat is measuring the waist of the woman on the right (wearing street clothes) with a tape measureShare on Pinterest
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What first-week side effects can I expect with Wegovy?

In their first week of treatment, some people may develop side effects. These might occur within hours to days of their first dose. But the timing and degree of side effects vary widely among people.

Some of the most common side effects of Wegovy include:

Learn what you might expect with Wegovy once you’ve completed your first week of treatment.

What results can I expect in the first month and later?

It depends. Some people may find that Wegovy is effective for weight loss. Others might not lose much or any weight. Losing weight can take longer for some people, and it may be affected by the dosage of Wegovy and the length of treatment.

A 2021 study compared weight loss in people taking semaglutide and people taking a placebo. (A placebo is a substance with no active drug or ingredient.) Researchers found that weight loss at 4 weeks was statistically significant in those taking semaglutide. They also found that weight loss reached its maximum at 60 weeks of treatment.

What side effects can I expect in the first month and later?

It’s not uncommon to experience side effects after your first week of Wegovy treatment. But keep in mind that the timing and degree of side effects vary widely among people.

If you do develop side effects, it’s important to know that doesn’t mean you are more or less likely to experience weight loss. During Wegovy treatment, common side effects in the first month and later include:

  • nausea and vomiting
  • diarrhea
  • constipation

In clinical studies, some people had side effects that persisted. About 8% of these people discontinued medications containing semaglutide (the active ingredient in Wegovy).

It’s believed that Wegovy decreases appetite due to direct and indirect effects on the brain. This causes you to eat less food (thus taking in fewer calories), which results in weight loss. This may help reduce some cardiovascular and other risks associated with obesity, overweight, and MASH.

During Wegovy treatment, you might notice some things in how you feel. You might experience differences in:

Your appetite: With Wegovy, people generally recognize when they’re full after a snack or a meal. Some also report staying full longer. Others note that they eat less.

Food cravings: Numerous people find that they have fewer cravings for certain foods. They find that they’re able to ignore cravings to snack or eat more easily.

Wanting to eat: Some people are familiar with the desire to eat when they’re not hungry. With Wegovy, they may experience that desire less.

Food choices: Compared with their before-treatment choices, many people report that they choose healthier foods to eat. They also note that they can account for why they made these choices.

Some day-to-day choices: With Wegovy, people sometimes find that they make different choices about activities. Some make choices that are not centered around food, such as going out but not necessarily going out to eat.

It’s possible that you could experience other health-related differences in how you feel. Some may be obvious and others not. Examples include:

  • weight loss
  • improved heart health
  • lowered blood pressure
  • lowered blood sugar
  • lower cholesterol
  • reduced inflammation
  • improved overall functioning of the body

Some differences concerning weight loss and heart health will depend on your specific condition. They also may depend on other medications you take and other conditions you may have.

You can help increase or promote weight loss with Wegovy in several ways. This section discusses a few of those.

Choose nutritious foods to help reduce calories

For several of Wegovy’s prescribed uses, doctors also prescribe a diet with fewer calories. To intake fewer calories, you can choose foods that are dense in nutrients. These include:

  • fruits
  • vegetables
  • whole grains
  • healthy protein sources

Rightsize your portions

You can help intake fewer calories when you control portion sizes. Try to form the habit of checking serving sizes on nutrition labels to guide your portion sizes. Rather than using a dinner plate, you can select a smaller dish and fill it with one serving.

Eat slowly

Eat at a slower pace. Enjoy the textures, aromas, and flavors of your food.

Keep water handy

Water can help you feel full. Plus, it can keep you energized and hydrated. Keep a water bottle nearby and even in several places so you’ll always have one handy.

Increase your physical activity

Along with prescribing fewer calories, doctors also may prescribe increased physical activity with Wegovy. Some suggestions are:

  • Find what’s fun in fitness: Discover ways to stay active that you can enjoy. Explore by walking, dancing, jogging, weightlifting, playing tennis, or doing other activities that keep you moving.
  • Go with a buddy: Plan physical activities with family and friends. While you spend time together, you can work toward your weight-management goals.
  • Bundle the activity with what interests you: Do your workout or activity with something that makes you want to do it. You could try working out or other physical activity while you:
    • listen to music you love
    • catch up on your favorite TV program
    • listen to a podcast
    • explore your favorite park
  • Change up activities: Try changing activities here and there to keep your interest high. You could try walking vigorously one day and then running lightly the next. Or use weights while you walk or dance instead of just weightlifting.
Medical Perspective

How does exercise affect blood sugar levels and insulin sensitivity?

“Exercise increases uptake of glucose by your muscles and liver so that your body can use it for energy. Your body then takes glucose from your blood to rebuild these stores, thereby lowering blood sugar. Exercise also makes your body more sensitive to insulin, so you will need less insulin during and after activity.”

— Kelly Wood, MD

Learn more about exercising safely if you take insulin.

Quotes represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

Wegovy is an FDA-approved medication for weight loss in certain people who are overweight or have obesity. It is also FDA approved for other uses, including MASH.

You’re not likely to notice weight loss within your first week of treatment. But your doctor may notice changes in some of your health markers, such as your blood pressure or blood sugar. Over time, you could notice other differences in your appetite, how you feel, and more.

You may develop side effects during the first week of treatment or later. The most common side effects of Wegovy affect your gastrointestinal tract. These include:

  • nausea
  • vomiting
  • constipation
  • diarrhea

Side effects may ease as your body becomes used to the medication.

Your doctor may be able to lessen some side effects of Wegovy by adjusting your dose. Be sure to discuss adjusting your dose with your doctor rather than adjusting it on your own. Your doctor also might recommend OTC treatments for some side effects if you find that home remedies aren’t effective.

Disclaimer: While Healthline strives for factual, comprehensive, and current information, this article is not a substitute for a licensed healthcare professional’s expertise. Always consult a doctor before taking or discontinuing any medication. Drug information is subject to change and may not cover all uses, directions, precautions, warnings, interactions, reactions, or adverse effects. The lack of a warning does not guarantee a drug’s safety, effectiveness, or appropriateness for all patients or specific uses. Learn more about our approach to content integrity.